Chronic Wasting Disease CWD TSE PrP, Cervid, Genetic Manipulation, Unforeseen Circumstances
Chronic Wasting Disease CWD TSE PrP, Cervid, Genetic Manipulation, Unforeseen Circumstances
ENGROSSED HOUSE BILL NO. 3270 By: Archer, Humphrey, Kannady, Lowe, Sterling, Schreiber, Townley, and Cantrell of the House and Murdock of the Senate
An Act relating to farmed cervidae; amending 2 O.S. 2021, Sections 6-507, as amended by Section 1, Chapter 47, O.S.L. 2023 (2 O.S. Supp. 2025, Section 6-507) and Section 1, Chapter 271, O.S.L. 2024 (2 O.S. Supp. 2025, Section 6-520), which relate to the Oklahoma Farmed Cervidae Act; exempting certain actions from violating act; allowing bred deer with certain genetic resistance to be released into native cervidae populations; changing department that issues permit from the Oklahoma Department of Wildlife Conservation to the Oklahoma Department of Agriculture, Food, and Forestry; and declaring an emergency...
https://www.oklegislature.gov/cf_pdf/2025-26%20ENGR/hB/HB3270%20ENGR.PDF
OKLAHOMA JUST RELEASED A CAPTIVE WHITETAIL DEER INTO THE WILD...ON PURPOSE
JORDAN SILLARS
Apr 10, 2026
For the first time ever, a captive-raised deer has been released into the wild whitetail population to slow the spread of Chronic Wasting Disease (CWD).
The historic move is part of a program instituted by the Oklahoma state legislature in 2024. The Chronic Wasting Disease Genetic Improvement Program is intended to bolster wild deer genetics by releasing captive deer that have a resistance—though not an immunity—to the always-fatal disease.
But opponents say that meaningfully improving wild herd genetics would require releasing hundreds of thousands of deer. What’s more, those releases could have the opposite effect: captive deer are not tested for CWD prior to release and may end up spreading the disease to new areas or introducing novel strains.
“That's not how you mitigate the disease,” said Catherine Appling-Pooler, the director of policy for the National Deer Association. “People have grabbed onto this research because it offers hope against a disease that is 100 percent fatal. But hope should not get in the way of science. We need to make sure this can be repeated, that it’s peer reviewed, and that it’s accepted by more than just one scientist.”
The concept of fighting CWD by improving the genetics in the wild herd has been pioneered by a Texas biologist named Dr. Chris Seabury. However, while farmers did something similar to eliminate scrapie in sheep herds, the technique has never been proven effective—or even tested—in wild populations.
State veterinarian Dr. Rod Hall confirmed in an email to MeatEater that a captive-raised deer was released in Wagoner County, Oklahoma. The animal met the genetic requirements of the state’s new genetic improvement program but was not tested for CWD. Appling-Pooler tells MeatEater as many as five more deer could be released on low-fence properties in Oklahoma before the April 15, 2026, deadline.
The release of this deer was not approved by wildlife professionals at the Oklahoma Department of Wildlife Conservation (ODWC). Instead, as per the language in the 2024 bill, the Oklahoma Department of Agriculture, Food, and Forestry (ODAFF) okayed the release according to their one-page list of requirements.
As MeatEater reported at the time, wildlife officials and hunting groups were shocked when the Genetic Improvement Program sailed through the Sooner State legislature. But not only did the bill pass on a nearly unanimous basis, it also left the ODWC with little input on whether and how these captive deer should be released into the wild. The bill said the wildlife agency “may” charge a one-time permit fee, but it gave the ODAFF the authority to promulgate rules for the program. It was unclear whether the ODWC also had the ability to impose permit requirements, and the agency never went through the rulemaking process. Frustrated by this perceived lack of action, Oklahoma Representative Nick Archer introduced House Bill 3270 during this legislative session. This bill entirely removes the ODWC from the decision-making process and grants permitting authority solely to the Department of Agriculture (ODAFF).
At the same time, the ODAFF is moving forward with deer releases.
“It's completely removing wildlife professionals from the program and from the conversation and from, most importantly, the decision making. And that's what NDA and others oppose. Wildlife professionals should be involved in decisions that directly impact wildlife in the state,” Appling-Pooler said. “It's not just about CWD. It's an overreach by the legislature on the department's authority to do their job.”
The Oklahoma Wildlife Conservation Commission has not historically endorsed or opposed specific pieces of legislation, but they have come out against HB 3270.
“HB 3270 would authorize a practice that has never been implemented in Oklahoma and has not been adopted by any state wildlife agency as a management tool,” the commission wrote in a position statement. “The Commission finds that such action warrants comprehensive scientific review and careful consideration of all potential unintended consequences before any implementation.”
One of those unintended consequences is the potential exclusion of all Oklahoma deer from the Boone & Crockett and Pope & Young record books. These organizations have always excluded genetically manipulated animals from their records, and releasing captive deer into Oklahoma’s wild herd might disqualify the entire herd.
The Oklahoma Department of Wildlife Commission held a meeting April 6, to which they invited several wildlife biologists to speak to this issue. (It’s worth checking out in its entirety here). One of them, Dr. Jennifer Malmberg of the National Wildlife Research Center, laid out a model showing how many deer would need to be released in order to improve the genetics of the wild herd.
susceptibility
Releasing a number of deer equal to 1% of the wild population would have almost no effect on the wild herd. There are an estimated 750,000 deer in Oklahoma, which means even if 7,500 CWD-resistant deer were released every year for 10 years, it would have a negligible effect on wild deer. Releasing 75,000 deer each year over 10 years would have a greater effect, but it still wouldn’t make the entire herd resistant (which, again, doesn’t make them immune).
What’s more, this model assumes a best-case scenario. It assumes captive deer will breed and survive at the same rate as wild deer (which is unlikely) and that there will be no landscape fragmentation that will affect gene flow (roads, cities, etc.).
While releasing a realistic number of captive deer would create very little benefit, it could result in significant cost. Dr. Malmberg noted it could spread CWD into new areas of the state, but it would also dramatically alter the behavior of deer in the Sooner State.
“It can alter deer density and resource selection. It’s very likely that deer that are released from captivity into the wild will use human resources, and we know that that results in more CWD,” she told the commission.
The Oklahoma State House voted to remove the ODWC from the whitetail release program on a 68-21 vote. This might seem one-sided, but it represents a significant uptick in opposition from 2024, when only three legislators voted against the program. HB 3270 now heads to the Senate, where it sits before the Agriculture and Wildlife Committee.
Appling-Pooler says despite the large margin of “Yes” votes in the House, the Senate might present more difficulties for this legislation.
“I am more optimistic than I usually am on this issue,” she said. “I have heard more opposition from legislators. They've been hearing from their constituents, and they are listening to their constituents, which is always really appreciated. I'm encouraged by the constituent engagement we've had.”
If you’d like to be one of those constituents—which include residents of neighboring states who might have an opinion on pen-raised deer mingling with wild animals—you can contact state legislators here. https://www.oklegislature.gov/FindMyLegislature.aspx
https://www.themeateater.com/wired-to-hunt/whitetail-management/oklahoma-just-released-a-captive-whitetail-deer-into-the-wild-on-purpose
Genetic Resistance CWD, or CWD TSE Prion Poker? 2026
are you all in$$$
putting the cwd cart before the horse, and at what cost, what could go wrong, right?
remember this;
PRIORITY, PROJECT FINAL REPORT
*** 14) Concluding that atypical scrapie can transmit to Humans and that its strain properties change as it transmits between species ***
see that reference below…end…TSS…2026
BY genetically manipulating genes for different species, trying to study Transmissible Spongiform Encephalopathy TSE in different species, has proven to be results, of unforeseen and unwanted circumstances. we also saw this with studies of scrapie research pens, where many say cwd was born. but, genetic manipulation of some species with the Transmissible Spongiform Encephalopathy TSE Prion disease, has shown to be a very dangerous game of TSE Prion Poker, and the end product can be aces and eights, a dead mans hand. so, who’s all in$
*** Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.
IN CONFIDENCE, REPORT OF AN UNCONVENTIONAL SLOW VIRUS DISEASE IN ANIMALS IN THE USA 1989
http://webarchive.nationalarchives.gov.uk/20080102193705/http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf
The Release of Farmed Genetically Manipulated Cervid, into the wild, manipulated to be less resistant or resistant, maybe, (no cervid to date has been documented to be totally resistant) to Chronic Wasting Disease CWD TSE Prion, without doing extensive research, and without testing for CWD TSE PrP, WHAT COULD POSSIBLY GO WRONG, in the short term, and long term, vertical, horizontal, environmental, zoonotic, zoonosis, species, specific ramifications from CWD? these studies must be done first. this is just another example of pay to play, legislative CWD, tse prion poker that was shoved down the throats of the fine people of Oklahoma, and it’s wild cervid population, of which every hunter should be very concerned with, i don’t care which side of the fence your from…
TSE Prion Poker is a no win game.
CWD Genetic Resistance?
“CWD positive animals with extended time before they succumb to disease likely represent a source of chronic prion shedding within populations and may contribute to environmental contamination.”
Experimental Oronasal Inoculation of the Chronic Wasting Disease Agent into White Tailed Deer
Author list: Sarah,b , S. Jo Moorea,b , Jifeng Biana , Eric D. Cassmanna , and Justin J. Greenleea . a. Virus and Prion Research Unit, National Animal Disease Center, ARS, United States Department of Agriculture, Ames, IA, US b. Oak Ridge Institute for Science and Education (ORISE), U.S. Department of Energy, Oak Ridge, TN, United States
Aims: The purpose of this experiment was to determine whether white-tailed deer (WTD) are susceptible to inoculation of chronic wasting disease (CWD) via oronasal exposure.
Materials and methods: Six male, neutered WTD were oronasally inoculated with brainstem material (10% w/v) from a CWD-positive wild-type WTD. The genotypes of five inoculated deer were Q95/G96 (wild-type). One inoculated deer was homozygous S at codon 96 (96SS). Cervidized (Tg12; M132 elk PrP) mice were inoculated with 1% w/v brainstem homogenate from either a 96GG WTD (n=10) or the 96SS WTD (n=10).
Results: All deer developed characteristic clinical signs of CWD including weight loss, regurgitation, and ataxia. The 96SS individual had a prolonged disease course and incubation period compared to the other deer. Western blots of the brainstem on all deer yielded similar molecular profiles. All deer had widespread lymphoid distribution of PrPCWD and neuropathologic lesions associated with transmissible spongiform encephalopathies. Both groups of mice had a 100% attack rate and developed clinical signs, including loss of body condition, ataxia, and loss of righting reflex. Mice inoculated with material from the 96SS deer had a significantly shorter incubation period than mice inoculated with material from 96GG deer (Welch two sample T-test, P<0.05). Serial dilutions of each inocula suggests that differences in incubation period were not due to a greater concentration of PrPCWD in the 96SS inoculum. Molecular profiles from western blot of brain homogenates from mice appeared similar regardless of inoculum and appear similar to those of deer used for inoculum.
Conclusions: This study characterizes the lesions and clinical course of CWD in WTD inoculated in a similar manner to natural conditions. It supports previous findings that 96SS deer have a prolonged disease course. Further, it describes a first pass of inoculum from a 96SS deer in cervidized mice which shortened the incubation period.
Funded by: This research was funded in its entirety by congressionally appropriated funds to the United States Department of Agriculture, Agricultural Research Service. The funders of the work did not influence study design, data collection, analysis, decision to publish, or preparation of the manuscript.
Acknowledgement: We thank Ami Frank and Kevin Hassall for their technical contributions to this project.
=====end
PRION 2023 CONTINUED;
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: Update: CWD genetic resistance project at NADC
Author item Cassmann, Eric item Greenlee, Justin
Submitted to: North American Deer Farmer Publication
Type: Trade Journal Publication Acceptance Date: 11/5/2023 Publication Date: 11/15/2023
Citation: Cassmann, E.D., Greenlee, J.J. 2023. Update: CWD genetic resistance project at NADC. North American Deer Farmer. P. 83. Interpretive Summary:
Technical Abstract: In March of 2020, we began a study to examine the susceptibility of whitetail deer with rare prion protein genotypes to chronic wasting disease (CWD). In the sequence of amino acids that make up the deer prion protein, there are several locations that are variable. These variations are sometimes called polymorphisms. In the data collected from depopulations, whitetail deer with certain prion gene polymorphisms were not positive for CWD. In 2019, Dr. Nick Haley published a paper that showed H95/S96, HH95, and S96/K226 deer from depopulated herds in the US were not CWD positive. Based on the overall low number of deer with these genotypes () we’re unable to determine if they were resistant to CWD or if there were too few deer with these genotypes to be statistically represented in the positive cases. It’s also possible that they could be partially susceptible with longer incubation times than deer with generic (wild type) prion genotypes.
Samples gathered at depopulation represent a snapshot of the herd. It is possible these rare genotypes were exposed, but had not yet accumulated abnormal prion protein to a level detectable by the detection methods used. The NADC susceptibility study was initiated to help answer these questions. We studied deer with polymorphisms at 3 amino acid locations (codons): 95, 96, and 226. Wild type deer are QQ95GG96QQ226. Whitetail deer with wild type prion genotypes were inoculated with CWD and co-housed with other whitetail deer (contact deer) that had rare prion protein genotypes. The genotypes of contact deer included QH95GS96QQ226, QH95GG96QK226, QQ95GS96QQ226, QQ95SS96QQ226, Q95GS96QK226, and QQ95GG96KK226 (bolded text indicates a prion gene polymorphism).
During the first year, we collected feces, saliva, nasal swabs, skin, blood, and rectal biopsies from the inoculated and contact deer to determine if deer are CWD positive and the period of CWD shedding. After the first year, we started collecting rectal biopsies annually on the contact deer, but all other samples are still collected every three months.
Eight out of ten (8/10) inoculated deer developed clinical signs for CWD and tested positive after necropsy (Figure 1). The average time from inoculation to euthanasia of these eight inoculated deer was 23 months. Two inoculated deer are still on-study; one of these deer has tested positive for CWD on rectal biopsy IHC.
To date, two deer from the contact group have developed CWD clinical signs and tested positive (Figure 2).
The positive deer from the contact group had the GS96QK226 and KK226 genotypes.
We have detected CWD prions in rectal biopsies with IHC in three other contact deer as of October 2023.
Their prion genotypes are GS96, QH95GS96, and GS96QK226.
As the experiment continues, we hope to answer 2 main questions.
(1) Are there any prion protein polymorphisms that make deer resistant to CWD, and
(2) what are the CWD shedding dynamics in deer with detectable CWD.
One potential outcome of the study would be identifying genotypes with very long incubation periods that, while susceptible to CWD, still could be used to manage CWD.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=410188
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Experiments have commenced to adapt the assays to differentiate classical scrapie prions in small ruminants from the prions that replicate in small ruminants after experimental exposure to chronic wasting disease prions from elk. Research has continued with aims to improve the application of current protocols and validate standardized novel protocols in the diagnosis of prion infection. The tonsil can be sampled by biopsy in living animals and a study in white-tailed deer was completed using a two-bite tonsil biopsy technique. The diagnostic sensitivity of immunohistochemistry on this tissue source was significantly reduced in deer with early-stage infection and in those carrying the G96S polymorphism.
https://www.ars.usda.gov/research/project/?accnNo=441236&fy=2025
Volume 30, Number 10—October 2024
Research
Temporal Characterization of Prion Shedding in Secreta of White-Tailed Deer in Longitudinal Study of Chronic Wasting Disease, United States
Our findings suggest that deer expressing alternative PRNP polymorphisms might live longer and, although they shed fewer prions throughout CWD course, might over their extended lifespan increase CWD prions in the environment
https://wwwnc.cdc.gov/eid/article/30/10/24-0159_article
Research Paper
Prion protein gene sequence and chronic wasting disease susceptibility in white-tailed deer (Odocoileus virginianus)
Received 21 Sep 2015, Accepted 23 Oct 2015, Accepted author version posted online: 03 Dec 2015, Published online: 21 Dec 2015
The presence of aa96S has been associated with slowed disease progression, longer life span among captive deer,Citation26,27 and does not appear to affect the rate at which prions are shed from infected individuals.Citation38 Additionally, CWD infected mule deer have been found to excrete pathogenic prions while asymptomatic.Citation39 This contributes to concerns that wild deer with aa96S may be shedding infectious prions into the environment for longer periods of time than deer lacking the mutation, but are not symptomatic or detectable by immunohistochemical procedures.
https://www.tandfonline.com/doi/full/10.1080/19336896.2015.1115179#d1e354
https://pmc.ncbi.nlm.nih.gov/articles/PMC4964855/pdf/kprn-09-06-1115179.pdf
Review on PRNP genetics and susceptibility to chronic wasting disease of Cervidae
Review
Open access
Published: 07 October 2021
Volume 52, article number 128, (2021)
“It seems so far that all deer, irrespective of their PRNPgenotype, are susceptible to CWD, but natural selection of the less susceptible alleles has been identified.”
“CWD positive animals with extended time before they succumb to disease likely represent a source of chronic prion shedding within populations and may contribute to environmental contamination.”
https://link.springer.com/article/10.1186/s13567-021-00993-z
Unrealistic Hopes
CAN SCIENCE BREED CWD OUT OF DEER? NOT LIKELY March 22, 2022 By: Patrick Durkin
Proponents of selective breeding hope CWD could be controlled in the wild by producing and releasing disease-proof deer from captive herds, but Samuel thinks that’s unrealistic.
“You’ll never produce enough genetically manipulated deer to overwhelm breeding in a wild population,” he said. “Maybe you could get 40%, 50% or 60% of the less susceptible genotypes out there, but that wouldn’t control CWD.”
Schuler and Samuel also note that science doesn’t yet know if CWD-resistant genotypes also carry physical or behavioral traits that would cause other problems.
“I’m not a geneticist, but these CWD-resistant genotypes aren’t found frequently in natural populations,” Schuler said. “The most CWD-resistant genotypes occur at very low rates, and there’s probably a reason for that. Those genotypes might carry traits that cause other population-limiting problems not yet documented.”
Snip…
Skeptical Scientists
But Krysten Schuler, a wildlife disease ecologist at New York’s Cornell University, is skeptical CWD can be controlled through selective breeding, inside or outside captive facilities.
“I doubt we’re going to breed our way out of this problem,” Schuler said. “It’s a pie-in-the-sky hope. No one has documented a deer surviving CWD, so no one has a truly CWD-resistant deer. Some deer take longer to get CWD, and they might live longer once they get it, but they still get CWD and it still kills them. So how can anyone say they can selectively breed more of something that doesn’t exist?”
Schuler said the most anyone has done is identify deer with relatively uncommon genotypes that delay CWD infection and prolong the deer’s life. “Those deer just take longer to get CWD, and they live maybe three years with it instead of the traditional one or two years,” she said. “You can separate deer in a captive facility, and maybe breed some of them to be more resistant, but that challenge is more problematic in wild herds.” “We have to be certain we’ve found a solution before we waste time and money trying to implement a plan that’s not going to work.” Schuler and Mike Samuel, professor emeritus at the University of Wisconsin-Madison, also worry that longer-lived CWD-infected deer could actually worsen CWD’s spread.
“Be careful what you wish for,” Samuel said. “CWD still has many unknowns and uncertainties. The longer an infected deer lives, the more contact it will have with other deer, and the more prions it will shed on the landscape. CWD prevalence in that herd would likely go up and you’d get more infections in younger deer. And if that happens, those younger deer would spread it farther and faster when dispersing.”
https://deerassociation.com/deer-resistance-cwd/#:~:text=Proponents%20of%20selective%20breeding%20hope%20CWD%20could%20be,overwhelm%20breeding%20in%20a%20wild%20population%2C%E2%80%9D%20he%20said.
Experimental transmission of ovine atypical scrapie to cattle
This study demonstrates for the first time that a TSE agent with BSE-like properties can be amplified in cattle inoculated with atypical scrapie brain homogenate.
https://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-023-01224-3
Timm Konold, John Spiropoulos, Janet Hills, Hasina Abdul, Saira Cawthraw, Laura Phelan, Amy McKenna, Lauren Read, Sara Canoyra, Alba Marín-Moreno & Juan María Torres
Veterinary Research volume 54, Article number: 98 (2023)
Abstract
Classical bovine spongiform encephalopathy (BSE) in cattle was caused by the recycling and feeding of meat and bone meal contaminated with a transmissible spongiform encephalopathy (TSE) agent but its origin remains unknown. This study aimed to determine whether atypical scrapie could cause disease in cattle and to compare it with other known TSEs in cattle. Two groups of calves (five and two) were intracerebrally inoculated with atypical scrapie brain homogenate from two sheep with atypical scrapie. Controls were five calves intracerebrally inoculated with saline solution and one non-inoculated animal. Cattle were clinically monitored until clinical end-stage or at least 96 months post-inoculation (mpi). After euthanasia, tissues were collected for TSE diagnosis and potential transgenic mouse bioassay. One animal was culled with BSE-like clinical signs at 48 mpi. The other cattle either developed intercurrent diseases leading to cull or remained clinical unremarkable at study endpoint, including control cattle. None of the animals tested positive for TSEs by Western immunoblot and immunohistochemistry. Bioassay of brain samples from the clinical suspect in Ov-Tg338 and Bov-Tg110 mice was also negative. By contrast, protein misfolding cyclic amplification detected prions in the examined brains from atypical scrapie-challenged cattle, which had a classical BSE-like phenotype. This study demonstrates for the first time that a TSE agent with BSE-like properties can be amplified in cattle inoculated with atypical scrapie brain homogenate.
snip...
This is the first study in cattle inoculated with naturally occurring scrapie isolates that found the presence of prions resembling classical BSE in bovine brain although this was limited to detection by the ultrasensitive PMCA. The results from thermostability assay confirmed that the isolates were as thermoresistant as the BSE agent as proven in other studies [36, 48]. Previous PMCA studies with various British atypical scrapie isolates did not find any evidence of amplification [49, 50]. This may be explained by the use of ovine brain as substrate rather than brain from Bov-Tg110 mice, which may facilitate conversion to classical BSE prions.
Two hypotheses for prion strain propagation in cross-species transmission experiments have been proposed: conformational selection favours a particular strain conformation out of a mixture of conformations in a scrapie isolate whilst mutation results in the conformational shift of one conformation into another [51]. Following on from the study in mice [17], it has been subsequently suggested that classical BSE properties that arise in atypical scrapie isolates transmitted to cattle may be due to conformational mutation in a new host [52]. It does not confirm that the atypical scrapie agent is the origin of the classical BSE epidemic and further transmission studies would be required to see whether classical BSE can be generated.
Would PMCA applied to brains from cattle exposed to TSE agents other than classical BSE and atypical scrapie also produce a classical BSE-like molecular phenotype? The PMCA product obtained in the thermostability test using a thermosensitive classical scrapie control showed a profile unlike classical BSE. Atypical BSE has been linked to the origin of classical BSE because of its conversion into classical BSE following serial passages in wild-type mice (L-type BSE [11]) and bovine transgenic mice (H-type BSE [53]). Although we have not tested PMCA products of atypical BSE isolates as part of this study, there is no evidence that PMCA products from atypical BSE convert into classical BSE, at least for H-type BSE using bovine brain as substrate [54]. In fact, we were unable to propagate H-type BSE using the same methodology (S Canoyra, A Marín-Moreno, JM Torres, unpublished observation).
The study results support the decision to maintain the current ban on animal meal in feedstuffs for ruminants, particularly as atypical scrapie occurs world-wide, and eradication is unlikely for a sporadic disease.
In summary, experimental inoculation of cattle with the atypical scrapie agent may produce clinical disease indistinguishable from classical BSE, which cannot be diagnosed by conventional diagnostic tests, but prions can be amplified by ultrasensitive tests in both clinically affected and clinically unremarkable cattle, which reveal classical BSE-like characteristics. Further studies are required to assess whether a BSE-like disease can be confirmed by conventional tests, which may initially include a second passage in cattle.
https://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-023-01224-3
Classical BSE prions emerge from asymptomatic pigs challenged with atypical/Nor98 scrapie
Transmission of atypical scrapie to bovinized mice resulted in the emergence of C-BSE prions.
https://www.nature.com/articles/s41598-021-96818-2
Belén Marín, Alicia Otero, Séverine Lugan, Juan Carlos Espinosa, Alba Marín-Moreno, Enric Vidal, Carlos Hedman, Antonio Romero, Martí Pumarola, Juan J. Badiola, Juan María Torres, Olivier Andréoletti & Rosa Bolea
Scientific Reports volume 11, Article number: 17428 (2021) Cite this article
Abstract
Pigs are susceptible to infection with the classical bovine spongiform encephalopathy (C-BSE) agent following experimental inoculation, and PrPSc accumulation was detected in porcine tissues after the inoculation of certain scrapie and chronic wasting disease isolates. However, a robust transmission barrier has been described in this species and, although they were exposed to C-BSE agent in many European countries, no cases of natural transmissible spongiform encephalopathies (TSE) infections have been reported in pigs. Transmission of atypical scrapie to bovinized mice resulted in the emergence of C-BSE prions. Here, we conducted a study to determine if pigs are susceptible to atypical scrapie. To this end, 12, 8–9-month-old minipigs were intracerebrally inoculated with two atypical scrapie sources. Animals were euthanized between 22- and 72-months post inoculation without clinical signs of TSE. All pigs tested negative for PrPSc accumulation by enzyme immunoassay, immunohistochemistry, western blotting and bioassay in porcine PrP mice. Surprisingly, in vitro protein misfolding cyclic amplification demonstrated the presence of C-BSE prions in different brain areas from seven pigs inoculated with both atypical scrapie isolates. Our results suggest that pigs exposed to atypical scrapie prions could become a reservoir for C-BSE and corroborate that C-BSE prions emerge during interspecies passage of atypical scrapie.
snip...
Discussion The outbreak of C-BSE was followed by the appearance of TSE in species that had never been diagnosed with prion diseases and the emergence in humans of vCJD16,17,18. However, no natural prion disease has been described in pigs, even though they were exposed to C-BSE contaminated feed12. Posterior experimental challenges in pigs and mice expressing porcine PrP have demonstrated that, although they are not completely resistant, pigs present a robust transmission barrier for C-BSE prions4,14,19.
However, the possible transmission of a TSE to swine is a public health concern due to the wide use of pork as a source of human food, and the increasing use of pigs as tissue donors, being reported a case of vCJD in a human patient receiving a swine dura mater graft20. Although pigs are apparently non-susceptible to C-BSE after oral challenge4,5,21, infectivity has been detected in tissues from pigs orally inoculated with classical scrapie or CWD10,11. In addition, these positive orally inoculated pigs are often subclinical, what could represent a public health concern, considering that these animals could reach the slaughterhouse without showing signs suggestive of prion disease.
In the present study, we evaluated the transmissibility of atypical scrapie to pigs. Pigs were euthanized between 22- and 72-months post inoculation (mpi), and their tissues tested for PrPSc accumulation and infectivity. We did not find evidence of transmission of atypical scrapie to any of the animals by EIA (Table 2), western blotting, or mouse bioassay (Table 3). PrPSc accumulation can be detected in BSE-challenged pigs at 34 mpi4, and at 22 mpi when inoculated with SBSE7. Although scrapie or CWD-inoculated pigs do not show clinical signs, PrPSc presence can be found in scrapie-challenged animals at 51 mpi11 and as early as 6 mpi in the case of CWD10.
Our main goal was to test the ability of atypical scrapie/Nor98 strain to propagate in swine, given that mice expressing porcine PrP (PoPrP-Tg001/tgPo mice) showed to be susceptible to atypical scrapie inoculation. One atypical scrapie isolate adapted to this transgenic line, reaching a 100% attack rate and rapid incubation periods in serial passages13, a similar adaptation to that observed with the C-BSE agent19. However, when this atypical scrapie isolate was tested for propagation in tgPo mice again, together with other atypical scrapie isolates, no positive results were obtained, in vitro nor in vivo14. These results, together with the negative transmissions showed in the present study, reinforce the conclusion that porcine species is highly resistant to atypical scrapie. However, we only performed one passage in tgPo mice, and further passages in this line and/or PMCA analysis of tgPo brains to detect any possible prion replication would be of interest.
However, it was demonstrated that C-BSE prions can be present as a minor variant in ovine atypical scrapie isolates and that C-BSE can emerge during the passage of these isolates to bovine PrP mice15. Considering that the aforementioned atypical scrapie isolate also acquired BSE-like properties when transmitted to tgPo mice13, and that C-BSE is the only prion that efficiently propagates in swine PrP4,7,14, we decided to investigate whether C-BSE prions could emerge from atypical scrapie during the ovine-porcine interspecies transmission.
Interestingly, PMCA reactions seeded with brain material from 7 pigs propagated in tgBov substrate showing PrPres with identical biochemical characteristics to those of C-BSE (Fig. 1). Positive C-BSE amplification was detected in the brain of pigs inoculated with either the PS152 or TOA3 atypical scrapie isolates, at minimum incubation periods of 28- and 35-months post inoculation, respectively. From each animal, positive reactions were not obtained from all brain areas tested (Supplementary table 1). Although PrPres amplified from the pigs showed C-BSE biochemical characteristics, further bioassays in tgBov mice are required to know whether these prions replicate the neuropathological features of C-BSE.
Altogether, our results and data obtained from transmission studies of prions to pigs, tgPo mice and in vitro studies using porcine substrate have shown that pig PrP has a very limited ability to sustain prion replication. No significant polymorphisms have been described for pig PRNP22, and it has been suggested that the conformational flexibility of pig PrP sequence is very low, limiting the number of PrPSc conformations able to produce misfolding14. No differences have been found between pig and minipig PrP sequences either23, suggesting that the conclusions obtained here could be extrapolated to domestic, non-experimental pigs. However, using tgBov substrate, we have demonstrated in vitro the presence of C-BSE seeding activity in some pig brain areas, suggesting that C-BSE prions emerged during the transmission of ovine atypical scrapie prions to pigs. Interestingly, C-BSE prions did not emerge from brain material of all the pigs, and, of those from which it did emerge, it was not detected in all brarsain areas tested. No correlation between time after inoculation and BSE emergence was found either. When the emergence of C-BSE from atypical scrapie in PMCA was described, it was associated to low levels of C-BSE prions that were present in the original atypical scrapie isolates15. It is possible that this result is related to the great resistance that pigs present to prion diseases, making the penetrance of the BSE prions that could be present in the original inoculum incomplete. In addition, considering that the amount of C-BSE conformers in the atypical scrapie inocula is probably very reduced and perhaps not homogeneously distributed throughout the isolate, it is also possible that not all the pigs received a sufficient amount of C-BSE conformers capable of being detected by PMCA. Finally, we should consider that PMCA amplification of prions is sometimes a stochastic phenomenon, which could explain why no C-BSE propagation was obtained from some of the pigs. It could be also discussed that C-BSE emergence from the pig brains could be related to persistence of the original atypical scrapie inoculum. However, C-BSE amplification was not obtained from all of the pigs and, in some of them (i.e. P-1217 and P-1231) C-BSE propagation was detected in caudal regions of the brain (cerebellum or occipital cortex) but not in more rostral areas (such as parietal cortex). If C-BSE amplification from pig brain samples were associated to inoculum persistence and not bona fide propagation of C-BSE prions it would be expected that such amplification would be detected mainly in the most rostral areas of the brain. Finally, even though the titer generated was not enough to produce disease in the pigs, these results evidence again the issue that pigs could act as subclinical reservoirs for prion diseases as observed with scrapie and CWD, and that the presence of prions can be detected in pigs short after exposure to prions7,10,11.
In conclusion, our findings suggest that, although pigs present a strong transmission barrier against the propagation of atypical scrapie, they can propagate low levels of C-BSE prions. The prevalence of atypical scrapie and the presence of infectivity in tissues from atypical scrapie infected sheep are underestimated24,25. Given that pigs have demonstrated being susceptible to other prion diseases, and to propagate prions without showing signs of disease, the measures implemented to ban the inclusion of ruminant proteins in livestock feed must not be interrupted.
https://www.nature.com/articles/s41598-021-96818-2
https://www.hjortevilt.no/bekrefter-atypisk-skrantesjuke-pa-hjort-i-etne/?fbclid=IwAR3MGseZb7apE5WXo34vyLRzaElC1OGPn95J-7Q_WQbD93pe-yuWK40N5YM
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
Title: Transmission of the atypical/nor98 scrapie agent to suffolk sheep with VRQ/ARQ, ARQ/ARQ, and ARQ/ARR genotypes
Author
item Cassmann, Eric
item MAMMADOVA, JAJIBA - Orise Fellow
item BENESTAD, SYLVIE - Norwegian Veterinary Institute
item MOORE, SARA JO - Orise Fellow
item Greenlee, Justin
Submitted to: PLoS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2021
Publication Date: 2/11/2021
Citation: Cassmann, E.D., Mammadova, J., Benestad, S., Moore, S., Greenlee, J.J. 2021. Transmission of the atypical/nor98 scrapie agent to suffolk sheep with VRQ/ARQ, ARQ/ARQ, and ARQ/ARR genotypes. PLoS ONE. 16(2). Article e0246503. https://doi.org/10.1371/journal.pone.0246503.
DOI: https://doi.org/10.1371/journal.pone.0246503
Interpretive Summary: Atypical scrapie is a prion disease that affects sheep. Unlike classical scrapie, atypical scrapie is thought to occur spontaneously, and it is unlikely to transmit between sheep under natural conditions. Another notable distinction between classical and atypical scrapie is the prion protein genotype of afflicted sheep and the locations in the brain where misfolded prions accumulate. Atypical scrapie generally occurs in sheep that are resistant to classical scrapie. Misfolded prions are predominantly found in the cerebellum for atypical scrapie and not in the brainstem as seen with classical scrapie. Atypical scrapie is a relevant disease because of its potential association with other prion diseases. Some research has shown that the atypical scrapie agent can undergo a transformation of disease forms that makes it appear like classical scrapie or classical bovine spongiform encephalopathy (mad cow disease). Therefore, atypical scrapie is thought to be a possible source for these prion diseases. We investigated the transmission of the atypical scrapie agent to sheep with three different prion protein genotypes. A diagnosis of atypical scrapie was made in all three genotypes of sheep. Misfolded prion protein was detected earliest in the cerebellum and the retina. This is the first report describing the early accumulation of misfolded prions in the retina of sheep with atypical scrapie. Understanding where misfolded prions accumulate in cases of atypical scrapie can lead to better detection earlier in the disease. Furthermore, the materials derived from this experiment will aid in investigating origins of other prion diseases.
Technical Abstract: Scrapie is a transmissible spongiform encephalopathy that occurs in sheep. Atypical/Nor98 scrapie occurs in sheep with that tend to be resistant to classical scrapie and it is thought to occur spontaneously. The purpose of this study was to test the transmission of the Atypical/Nor98 scrapie agent in three genotypes of Suffolk sheep and characterize the distribution of misfolded prion protein (PrPSc). Ten sheep were intracranially inoculated with brain homogenate from a sheep with Atypical/Nor98 scrapie. All sheep with the ARQ/ARQ and ARQ/ARR genotypes developed Atypical/Nor98 scrapie confirmed by immunohistochemistry, and one (1/3) sheep with the VRQ/ARQ genotype had detectable PrPSc consistent with Atypical/Nor98 scrapie at the experimental endpoint of 8 years. Sheep with mild early accumulations of PrPSc in the cerebellum had concomitant retinal PrPSc. Accordingly, large amounts of retinal PrPSc were identified in clinically affected sheep and sheep with dense accumulations of PrPSc in the cerebellum.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=379280
Research article
Open Access
Goat K222-PrPC polymorphic variant does not provide resistance to atypical scrapie in transgenic mice
Patricia Aguilar-Calvo1, 6, Juan-Carlos Espinosa1, Olivier Andréoletti2, Lorenzo González3, Leonor Orge4, Ramón Juste5 and Juan-María Torres1Email author Veterinary Research201647:96 DOI: 10.1186/s13567-016-0380-7
© The Author(s) 2016
Received: 11 June 2016
Accepted: 1 September 2016
Published: 22 September 2016
Abstract Host prion (PrPC) genotype is a major determinant for the susceptibility to prion diseases. The Q/K222-PrPC polymorphic variant provides goats and mice with high resistance against classical scrapie and bovine spongiform encephalopathy (BSE); yet its effect against atypical scrapie is unknown. Here, transgenic mice expressing the goat wild-type (wt) or the K222-PrPC variant were intracerebrally inoculated with several natural cases of atypical scrapie from sheep and goat and their susceptibility to the prion disease was determined. Goat wt and K222-PrPC transgenic mice were 100% susceptible to all the atypical scrapie isolates, showing similar survival times and almost identical disease phenotypes. The capacity of the K222-PrPC variant to replicate specifically the atypical scrapie strain as efficiently as the goat wt PrPC, but not the classical scrapie or cattle-BSE as previously reported, further suggests the involvement of concrete areas of the host PrPC in the strain-dependent replication of prions.
snip...
Susceptibility to prions and disease phenotypes are likely modulated by conformational properties of prion strains and the PrPC and PrPSc amino acid sequence [13]. Some host PrPC amino acid sequences may have greater “plasticity” or ability to misfold—as proposed for the unique susceptibility of bank voles to a wide variety of prion diseases [14] and to “in vitro” conversion experiments [15]—while others may show the opposite situation, locking PrPC and preventing its conversion by different prion strains. Nonetheless, the plasticity of the host PrPC would not explain why certain amino acid substitutions inhibit the replication of some prion strains but not others. A clear example is the goat K222 variant which provides high resistance against classical scrapie and bovine spongiform encephalopathy (BSE) from cattle—being protective even in heterozygous mice and goats [5, 6, 9]—but it is as efficient as the goat wt PrPC in replicating sheep and goat-BSE [5] and atypical scrapie when intracerebrally inoculated. The resistance of the K222 variant to classical scrapie was associated to the additional positive charge at codon 222 provided by the lysine amino acid, which could interfere with the PrPC:PrPSc interaction, abolishing or lowering the conversion rates of PrPC [16]. Similarly, the perturbations in the PrPC surface charge distribution and structural rearrangements mainly localized at the β2–α2 loop region (residues 169–179 in goat PrPC numbering) are likely to underlie the resistance of the human E/K219 variant against CJD [17].
More recently, the existence of critical initial PrPC–PrPSc interaction sites during the templating of PrPC by different prions was proposed [18]. The involvement of specific PrPC areas in the strain-dependent replication of prions could account for the variable role of the K222-PrPC variant in the susceptibility to scrapie. While for classical scrapie polymorphic variants along the PrPC have been associated to modulate the susceptibility to the disease, for atypical scrapie only few have been reported—A/V136, F/L141, R/H154 and Q/R171 [4, 19]— that, interestingly, are all located within β1–α1 and β2–α2 loops. This area could be the critical segment for atypical scrapie interaction with the host PrPC and therefore any amino acid exchange outside this segment would not affect the capacity of replication of the atypical scrapie, as observed in our transmission study in goat wt and K222-PrPC mice. In fact this area seems to be accessible in the abnormally folded aggregate of the atypical scrapie agent as suggested by the observation that the C-terminal part of atypical scrapie PrPSc can be specifically trimmed by PK [20]. In conclusion, although more information is still needed to decipher the mechanisms of prion conversion, our study points to the involvement of specific PrPC areas in the strain-dependent replication of prions. Thus, strategies to fight prion diseases based on genotype breeding programs should be prion strain targeted.
http://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-016-0380-7
*** Grant Agreement number: 222887 ***
*** Project acronym: PRIORITY ***
*** Project title: Protecting the food chain from prions: shaping European priorities through basic and applied research Funding ***
Scheme: Large-scale integrating project Period covered: from Oct. 1, 2009 to Sept. 30, 2014
Name of the scientific representative of the project's co-ordinator1, Title and Organisation: Jesús R. Requena, Ph.D., Associate Professor, Department of medicine, University of Santiago de Compostela, Spàin. Tel: 34-881815464 Fax: 34-881815403 E-mail: jesus.requena@usc.es
Project website¡ Error! Marcador no definido. address: www.prionpriority.eu
PRIORITY, PROJECT FINAL REPORT
*** 14) Concluding that atypical scrapie can transmit to Humans and that its strain properties change as it transmits between species ***
snip...
http://cordis.europa.eu/docs/results/222/222887/final1-priority-final-report.pdf
see;
https://nor-98.blogspot.com/2016/09/goat-k222-prpc-polymorphic-variant-does.html
Block D: Prion epidemiology
Studies on atypical scrapie were identified as a key element of this block, given the potential risk associated to this agent. We studied the permeability of Human, bovine and porcine species barriers to atypical scrapie agent transmission. Experiments in transgenic mice expressing bovine, porcine or human PrPC suggest that this TSE agent has the intrinsic ability to propagate across these species barriers including the Human one. Upon species barrier passage the biological properties and phenotype of atypical scrapie seem to be altered. Further experiments are currently ongoing (in the framework of this project but also in other projects) in order to: (i) characterize the properties of the prion that emerged from the propagation of atypical scrapie in tg Hu; (ii) to confirm that the phenomena we observed are also true for atypical scrapie isolates other than the ones we have studied.
In parallel, studies in sheep have concluded that:
*** Atypical scrapie can be transmitted by both oral and intracerebral route in sheep with various PRP genotypes
*** Low but consistent amount of infectivity accumulates in peripheral tissue (mammary gland, lymph nodes, placenta, skeletal muscles, nerves) of sheep incubating atypical scrapie.
*** The combination of data from all our studies leads us to conclude that:
*** Atypical scrapie passage through species barriers can lead to the emergence of various prions including classical BSE (following propagation in porcine PRP transgenic mice).
*** Atypical scrapie can propagate, with a low efficacy, in human PrP expressing mice. This suggests the existence of a zoonotic potential for this TSE agent.
snip...
We advance our main conclusions and recommendations, in particular as they might affect public policy, including a detailed elaboration of the evidence that led to them. Our main recommendations are:
a. The issue of re-introducing ruminant protein into the food-chain The opinion of the members of Priority is that sustaining an absolute feed ban for ruminant protein to ruminants is the essential requirement, especially since the impact of non-classical forms of scrapie in sheep and goats is not fully understood and cannot be fully estimated. Therefore, the consortium strongly recommends prohibiting re-introduction of processed ruminant protein into the food-chain. Arguments in support of this opinion are:
• the large (and still uncharacterized) diversity of prion agents that circulate in animal populations;
• the uncertainties related to prion epidemiology in animal populations;
• the unknown efficacy of industrial processes applied to reduce microbiological risk during processed animal protein (PAP) production on most prion agents; • the intrinsic capacity of prions to cross interspecies transmission barriers; • the lack of sensitive methodology for identifying cross contamination in food.
• the evolution of natural food chains in nature (i.e. who eats whom or what) has generated an efficient barrier preventing, to some extent, novel prion epidemies and that this naturally evolved ecology should be respected.
The consortium is also hesitant to introduce processed ruminant proteins into fish food considering the paucity of data on prion infections in fishes and sea animals including those of mammalian origin, and the risk of establishing an environmental contamination of the oceans that cannot be controlled.
b. Atypical prion agents and surveillance
Atypical prion agents (see below) will probably continue to represent the dominant form of prion diseases in the near future, particularly in Europe.
*** Atypical L-type BSE has clear zoonotic potential, as demonstrated in experimental models.
*** Similarly, there are now some data that seem to indicate that the atypical scrapie agent can cross various species barriers.
*** Moreover, the current EU policy for eradicating scrapie (genetic selection in affected flocks) is ineffective for preventing atypical scrapie.
*** The recent identification of cell-to-cell propagation and the protein-encoded strain properties of human neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, suggest that they bear the potential to be transmissible even if not with the same efficiency as CJD. More epidemiological data from large cohorts are necessary to reach any conclusion on the impact of their transmissibility on public health. Re-evaluations of safety precautions may become necessary depending on the outcome of these studies. In that context it would appear valuable
• to develop knowledge related to the pathogenesis and inter-individual transmission of atypical prion agents in ruminants (both intra- and inter-species)
• to improve the sensitivity of detection assays that are applied in the field towards this type of agent
• to maintain a robust surveillance of both animal and human populations
c. The need for extended research on prions
Intensified searching for a molecular determinants of the species barrier is recommended, since this barrier is a key for many important policy areas - risk assessment, proportional policies, the need for screening of human products and food. In this respect, prion strain structural language also remains an important issue for public health for the foreseeable future. Understanding the structural basis for strains and the basis for adaptation of a strain to a new host will require continued fundamental research. Prions maintain a complex two-way relationship with the host cell and fundamental research is needed on mechanisms for their transmission, replication and cause of nervous system dysfunction and death.
Early detection of prion infection, ideally at preclinical stage, also remains crucial for development of effective treatment strategies in humans affected by the disease.
Position of the Priority consortium
Nearly 30 years ago, the appearance in the UK of Bovine Spongiform Encephalopathy (BSE) quickly brought the previously obscure “prion diseases” to the spotlight. The ensuing health and food crises that spread throughout Europe had devastating consequences. In the UK alone, there were more than 36,000 farms directly affected by BSE and the transmission of BSE prions to humans via the food chain has caused over 200 people in Europe to die from variant Creutzfeldt-Jakob disease (vCJD) (http://www.cjd.ed.ac.uk
Origins of prion epidemies
Classical BSE now appears to be under control, with 18 EU Member States having achieved the World Organisation for Animal Health (Office International Epizooties) „negligible risk‟ status (May 2014; http://www.oie.int/en/animal-health-in-the-world/official-disease-status/bse/list-of-bse-risk-status/), and the remaining MS assessed as „controlled‟ risk. Of note, research, including EU-funded research, has played a key role in this success: while the origin of the infection was never defined, the principle driver of the epidemic was identified as prions in Meat and Bone Meal (MBM). Tests based on prion protein-specific antibodies were developed, allowing detection of infected animals, and a better understanding of disease pathogenesis and the distribution of infectivity in edible tissues; experimental investigation of transmission barriers between different species allowed a rational estimation of risks, etc. All of this led to the implementation of rational and effective policies, such as the MBM ban to protect the animal feed chain, and the Specified Risk Material (SRM) regulations to protect the human food chain.
In spite of this progress, prions are still a threat. Epidemiological re-assessment indicates that the ∼10 year incubation period separating the peaks of the BSE and the vCJD epidemics is probably too short. In addition, results from a large number of human tonsil and appendix analyses in the UK suggest that there may be a high number of asymptomatic individuals who are positive for the disease-associated conformer prion protein PrPSc. While vCJD is the only form of human prion disease that has been consistently demonstrated to have lymphoreticular involvement, there has been no systematic investigation of lymphoid tissue in cases with other prion diseases.
The human prion problem
The clinical cases of vCJD identified to date have all shared a common PrP genotype (M129M), although one pre-clinical case was confirmed as an M129V heterozygote, and it has been mooted that perhaps only the M129M proportion of the population is susceptible. However, in the UK appendix study, PrP accumulation was described in samples representing every codon 129 genotype, raising the possibility that genotype does not confer resistance but instead modulates incubation period. Apart from the two UK studies, the lymphoid tissues of non-CJD patients have not been examined for the presence of PrPSc, so, these cases may not solely represent pre-clinical vCJD, but also other forms of prion disease.
Recent experiments in highly susceptible mouse models indicate the presence of infectivity in blood or blood components at late disease stages in sporadic CJD. The significance of this experimental finding for humans has to be explored in more detail and, at the present time, there is no evidence for the transmission of prions via blood in sporadic CJD. However a likely scenario is that all those with signs of infection or abnormal PrP accumulation in peripheral tissue could have infective blood, posing the risk for transmission via blood products, which has been clearly demonstrated in experimental models, and confirmed in several cases of vCJD in man. Altogether, these data clearly demonstrate the potential risk of a second wave of vCJD, particularly when the number people identified with lymphoid accumulation of PrPSc (16/32,411) gives a prevalence estimate in the UK of 493 per million, much higher than the number of clinical cases seen to date.
The animal prion problem
An increasing number of reports on cases of “atypical” BSE in cattle throughout the EU and beyond may lead to a new epidemic, particularly since we still do not understand all factors determining the species barrier. Ovine scrapie is another concern, because it could mask ovine BSE, presumably transmissible to humans. Scrapie is endemic and not likely to be eradicated soon, although current control measures are effective at greatly reducing disease incidence. Atypical forms, which may be spontaneous, are not affected by these control measures and these forms of disease will persist in the global animal population. The low prevalence of these disease forms makes effective surveillance very challenging. However, there is a clear risk attendant on ignoring these cases without an understanding of their possible zoonotic potential, particularly when most forms of human disease have no established aetiology. In summary, atypical cases of BSE and scrapie presently clearly outnumber classical cases in cattle and sheep in all member states.
We will highlight the state-of-the-art knowledge and point out scientific challenges and the major questions for research. Strategic objectives and priorities in Europe in the future for research that aims to control, eliminate or eradicate the threat posed by prions to our food and health are also indicated.
The Priority project has focused on 4 themes, namely the structure, function, conversion and toxicity of prions; detection of prions; mechanisms of prion transmission and spreading and epidemiology of prion diseases. This paper summarizes the opinions/positions reached within these themes at the end of the project.
http://cordis.europa.eu/docs/results/222/222887/final1-priority-final-report.pdf
see;
https://nor-98.blogspot.com/2016/09/goat-k222-prpc-polymorphic-variant-does.html
***> CWD TSE PrP Environmental Factors <***
Chronic wasting disease (CWD) prion detection in environmental and biological samples from a taxidermy site and nursing facility, and instruments used in surveillance activities
Available online 9 April 2025
Highlights
• CWD prions were identified in a taxidermy and deer nursing facility.
• Contaminated samples included waters, soils, dermestid beetles, domestic flies and a dumpster.
• Surgical instruments used to collect deer samples can get contaminated with CWD prions.
• Some of the infectious particles are readily released from surgical instruments when washed.
• Our results suggest that taxidermy practices actively contribute in the spreading of CWD.
Snip…
In summary, the information provided in this report demonstrate how anthropogenic activities, specifically taxidermy practices, animal processing, and rehabilitation of CWD susceptible species, may facilitate CWD transmission through the environmental dissemination of CWD prions. This study, along with future research efforts characterizing the overall level of infectivity, provides relevant information on managing CWD and to control its rapid geographic expansion. …
https://www.sciencedirect.com/science/article/abs/pii/S0048969725009544
Chronic wasting disease detection in environmental and biological samples from a taxidermy site
Results: The PMCA analysis demonstrated CWD seeding activity in some of the components of this facility, including insects involved in head processing, soils, and a trash dumpster.
Conclusions: Different areas of this property were used for various taxidermy procedures. We were able to detect the presence of prions in
i) soils that were in contact with the heads of dead animals, ii) insects involved in the cleaning of skulls, and iii) an empty dumpster where animal carcasses were previously placed.
This is the first report demonstrating that swabbing is a helpful method to screen for prion infectivity on surfaces potentially contaminated with CWD. These findings are relevant as this swabbing and amplification strategy may be used to evaluate the disease status of other free-ranging and captive settings where there is a concern for CWD transmissions, such as at feeders and water troughs with CWD-exposed properties. This approach could have substantial implications for free-ranging cervid surveillance as well as in epidemiological investigations of CWD.
Prion 2022 Conference abstracts: pushing the boundaries
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
Artificial mineral sites that pre-date endemic chronic wasting disease become prion hotspots
The Ames Research and Educational Center property, centrally located within the CWD zone of southwest Tennessee, contains 49 historical mineral supplementation sites that were decommissioned in 2012. Here, we demonstrate that 32 of the 49 (65%) mineral sites within Ames established prior to the regional CWD outbreak, serve as foci of environmental PrPCWD contamination. Detection of PrPCWD in soils from these artificial mineral sites was dependent on site-specific management efforts. Soil physical properties were very similar across sites and no correlation between PrPCWD detection and soil physical properties was found. The detection of PrPCWD in soils at attractant sites within an endemic CWD zone significantly advances our understanding of environmental PrPCWD accumulation dynamics, providing valuable information for advancing adaptive CWD management approaches.
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf
Shedding of Chronic Wasting Disease Prions in Multiple Excreta Throughout Disease Course in White-tailed Deer
Conclusions: These studies demonstrate: (a) CWD prion excretion occurs throughout infection; (2) PRNP genotype (GG≫GS/NT) influences the excreta shedding; and (3) detection sensitivity in excreta can vary with different RT-QuIC protocols. These results provide a more complete perspective of prion shedding in deer during the course of CWD infection.
Prion 2022 Conference abstracts: pushing the boundaries
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
"Additionally, we have determined that prion seeding activity is retained for at least fifteen years at a contaminated site following attempted remediation."
15 YEARS!
Detection of prions in soils contaminated by multiple routes
Results: We are able to detect prion seeding activity at multiple types of environmental hotspots, including carcass sites, contaminated captive facilities, and scrapes (i.e. urine and saliva). Differences in relative prion concentration vary depending on the nature and source of the contamination. Additionally, we have determined that prion seeding activity is retained for at least fifteen years at a contaminated site following attempted remediation.
Conclusions: Detection of prions in the environment is of the utmost importance for controlling chronic wasting disease spread. Here, we have demonstrated a viable method for detection of prions in complex environmental matrices. However, it is quite likely that this method underestimates the total infectious prion load in a contaminated sample, due to incomplete recovery of infectious prions. Further refinements are necessary for accurate quantification of prions in such samples, and to account for the intrinsic heterogeneities found in the broader environment.
Funded by: Wisconsin Department of Natural Resources
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
***> Infectious agent of sheep scrapie may persist in the environment for at least 16 years
***> Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded.
JOURNAL OF GENERAL VIROLOGY Volume 87, Issue 12
Infectious agent of sheep scrapie may persist in the environment for at least 16 years Free
https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.82011-0
Rapid recontamination of a farm building occurs after attempted prion removal
First published: 19 January 2019 https://doi.org/10.1136/vr.105054
The data illustrates the difficulty in decontaminating farm buildings from scrapie, and demonstrates the likely contribution of farm dust to the recontamination of these environments to levels that are capable of causing disease. snip...
This study clearly demonstrates the difficulty in removing scrapie infectivity from the farm environment. Practical and effective prion decontamination methods are still urgently required for decontamination of scrapie infectivity from farms that have had cases of scrapie and this is particularly relevant for scrapie positive goatherds, which currently have limited genetic resistance to scrapie within commercial breeds.24 This is very likely to have parallels with control efforts for CWD in cervids.
https://bvajournals.onlinelibrary.wiley.com/doi/abs/10.1136/vr.105054
***>This is very likely to have parallels with control efforts for CWD in cervids.
https://pubmed.ncbi.nlm.nih.gov/30602491/
I remember what “deep throat” told me about Scrapie back around 2001, during early days of my BSE investigation, after my Mom died from hvCJD, I never forgot, and it seems it’s come to pass;
***> Confidential!!!!
***> As early as 1992-3 there had been long studies conducted on small pastures containing scrapie infected sheep at the sheep research station associated with the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are documented...I don't know. But personal recounts both heard and recorded in a daily journal indicate that leaving the pastures free and replacing the topsoil completely at least 2 feet of thickness each year for SEVEN years....and then when very clean (proven scrapie free) sheep were placed on these small pastures.... the new sheep also broke out with scrapie and passed it to offspring. I am not sure that TSE contaminated ground could ever be free of the agent!! A very frightening revelation!!!
---end personal email---end...tss
and so it seems…
Chronic Wasting Disease CWD TSE Prion
THE CWD TSE Prion aka mad cow type disease is not your normal pathogen.
The TSE prion disease survives ashing to 600 degrees celsius, that’s around 1112 degrees farenheit.
You cannot cook the TSE prion disease out of meat. In fact new data now shows that exposure to high temperatures used to cook the meat increased the availability of prions for in vitro amplification.
you can take the ash and mix it with saline and inject that ash into a mouse, and the mouse will go down with TSE.
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production as well.
the TSE prion agent also survives Simulated Wastewater Treatment Processes.
IN fact, you should also know that the TSE Prion agent will survive in the environment for years, if not decades.
you can bury it and it will not go away.
The TSE agent is capable of infected your water table i.e. Detection of protease-resistant cervid prion protein in water from a CWD-endemic area.
it’s not your ordinary pathogen you can just cook it out and be done
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
http://www.pnas.org/content/97/7/3418.full
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2493038/
Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals
https://bmcvetres.biomedcentral.com/track/pdf/10.1186/1746-6148-9-134.pdf
THURSDAY, FEBRUARY 28, 2019
BSE infectivity survives burial for five years with only limited spread
https://link.springer.com/content/pdf/10.1007%2Fs00705-019-04154-8.pdf
Chronic wasting disease prions on deer feeders and wildlife visitation to deer feeding areas
First published: 10 February 2025
Snip…
Finally, we swabbed 19 feeders in 2 areas where CWD was newly detected, finding prion contamination on swabs from 4 feeders. We show that deer feeders in free-ranging populations with high CWD prevalence become contaminated with CWD prions quickly, becoming a potential site of exposure of deer to CWD prions. Our results also demonstrate the ability to find evidence of prion contamination on deer feeders, even in areas where CWD is newly detected.
Snip…
We found that supplemental feeding increased the risk of exposure to CWD prions due to contamination of feeders, increased deer visitation, and increased deer-to-deer contact.
The 12-fold increase in deer visitation to feeders compared to mast trees and 2-fold increase compared to food plots demonstrates increased risk for direct disease spread.
https://wildlife.onlinelibrary.wiley.com/doi/10.1002/jwmg.70000
Chronic Wasting Disease in Texas A Real Disease with Proven Impacts
Produced by a coalition of concerned hunters, landowners, & conservationists (last update 1/2025)
storymaps.arcgis.com/stories/b93f528938ac48e9b56dcc79953cbec0
Aug 18, 2021
Oh, Deer
Heading Off a Wildlife Epidemic
CWD poses a significant threat to the future of hunting in Texas. Deer population declines of 45 and 50 percent have been documented in Colorado and Wyoming. A broad infection of Texas deer populations resulting in similar population impacts would inflict severe economic damage to rural communities and could negatively impact land markets. Specifically, those landowners seeking to establish a thriving herd of deer could avoid buying in areas with confirmed CWD infections. As they do with anthrax-susceptible properties, land brokers may find it advisable to inquire about the status of CWD infections on properties that they present for sale. Prospective buyers should also investigate the status of the wildlife on prospective properties. In addition, existing landowners should monitor developments as TPWD crafts management strategies to identify and contain this deadly disease.
Dr. Gilliland (c-gilliland@tamu.edu) is a research economist with the Texas Real Estate Research Center at Texas A&M University.
www.recenter.tamu.edu/articles/tierra-grande/oh-d
Scrapie, Humans, Zoonotic, what if?
=====
Transmission of scrapie prions to primate after an extended silent incubation period
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
https://www.nature.com/articles/srep11573
https://www.ars.usda.gov/research/publications/publication/?seqNo115=361032
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
==============
PRION 2015 CONFERENCE
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5019500/
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-68961933-690X
WS-01: Prion diseases in animals and zoonotic potential
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
Comparing the Distribution of Ovine Classical Scrapie and Sporadic Creutzfeldt-Jakob Disease in Italy: Spatial and Temporal Associations (2002-2014)
Ru G1 ., Pocchiari M2 ., Bertolini S. 1, Pite L.1 , Puopolo M.2 , Ladogana A.2 , Perrotta M.G.3 , Meloni D 1 . (1) National reference center for the study and research on animal encephalopathies and comparative neuropathologies (CEA). Experimental Zooprophylactic Institute of Piemonte, Liguria and Valle d'Aosta, Torino, Italy.
(2) Department of Cellular Biology and Neuroscience, Istituto Superiore di Sanità, Roma, Italy. (3) Office 3 National center for the fight and emergency against animal diseases. Ministry of Health, Roma, Italy.
Aim: This study aims to investigate potential spatial and temporal associations between Creutzfeldt-Jakob disease (CJD) in humans (2010-2014) and ovine classical scrapie (CS) (2002- 2006) in Italy, serving as a proxy for exposure.
Materials and Methods: National data from prion disease surveillance in humans (sporadic CJD) and small ruminants (CS) in Italy were utilized. A descriptive geographic analysis was conducted for each disease individually. Subsequently, an ecological study was performed to compare the occurrence of both diseases at the district and regional levels. Standardized incidence ratios (SIR), adjusted for confounders, were calculated for CJD and CS by district and region, respectively, representing the outcome and proxy of exposure. Considering a possible long incubation period of CJD, two study periods were analysed: 2010-2014 for CJD and 2002-2006 for CS. Eight alternative linear regression models were developed using SIR in humans as the dependent variable and SIR in sheep as the independent variable. These models varied in the scale of SIR data (continuous vs. categorical), geographical level (district vs. region), and the potential past exposure of sheep in specific areas to a known source of infection (via a contaminated vaccine).
Results: The analysis of data at the district level revealed no significant association. However, when considering aggregated regional data, all four models consistently indicated a statistically significant positive association, suggesting a higher incidence of the disease in humans as the regional incidence of sheep scrapie increased.
Conclusions: While the results are intriguing, it is important to acknowledge the inherent limitations of ecological studies. Nevertheless, these findings provide valuable evidence to formulate a hypothesis regarding the zoonotic potential of classical scrapie. Further investigations are necessary, employing specific designs such as analytical epidemiology studies, to test this hypothesis effectively.
Funded by: Italian Ministry of Health Grant number: Realizzazione del programma epidemiologico finalizzato a dare evidenza del potenziale zoonotico delle TSE animali diverse dalla BSE. Prot. N. 0018730-17/07/2015-DGSAFCOD_UO-P
''Nevertheless, these findings provide valuable evidence to formulate a hypothesis regarding the zoonotic potential of classical scrapie. Further investigations are necessary, employing specific designs such as analytical epidemiology studies, to test this hypothesis effectively.''
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
=====
Transmission of Idiopathic human prion disease CJD MM1 to small ruminant mouse models (Tg338 and Tg501).
Enric Vidal1,2, Samanta Giler1,2, Montse Ordóñez1,2, Hasier Eraña3,4, Jorge M. Charco3,4, Guillermo Cantero1,2, Juan C. Espinosa5 , Juan M. Torres5 , Vincent Béringue6 , Martí Pumarola7 and Joaquín Castilla3,8,9
Aims: About 90% of Creutzfeldt-Jakob disease cases are classified as sporadic (sCJD), that is, occur infrequently, randomly and without a known cause. It is a fatal neurodegenerative disease with an incidence of 1-1.5 cases per million per year. Epidemiological studies have been so far unable to establish a causal relationship between sCJD and prion diseases in animals.
The zoonotic potential of sheep scrapie was demonstrated in 2014 (Cassard et al., Nature Communications) through inoculation of transgenic mice overexpressing the human prion protein with scrapie isolates. The resulting prion disease was indistinguishable from that occurring after sCJD inoculation in the same model and, while these results do not demonstrate that sCJD is caused by scrapie prions, they do show that the transmission barrier between ovine and human prions is not absolute. Our aim is to further assess this zoonotic risk.
Materials and methods: we have prepared inocula from 3 sCJD cases (MM1, MV2 and VV2) and 2 VPSPr cases (MM and MV) to verify if it is possible to recover the scrapie phenotype upon inoculation in Tg338 and Tg501 ovinized mouse models. Additionally, two different inocula gCJD (E200K) and GSS (A117V) have been also included in the bioassays as controls for classical and atypical genetic human prions, respectively.
Results: No evidence of transmission was found on a first passage in Tg338 nor Tg501 ovinized mice, but on second passage, 4/10 Tg338 mice succumbed to CJDMM1 (40% attack rate after 645 dpi) and 1/12Tg501 mice (519dpi, 10 still alive). The remaining 2nd passages are still ongoing. Conclusions: In this poster, the neuropathological features of the resulting strain are discussed.
Funded by: MINECO grant number AGL2017-88535-P and PID2021-1222010B-C22 and by Interreg POCTEFA grant number EFA148/16 (RedPRION)
''but on second passage, 4/10 Tg338 mice succumbed to CJDMM1 (40% attack rate after 645 dpi) and 1/12 Tg501 mice (519dpi, 10 still alive). The remaining 2nd passages are still ongoing. Conclusions: In this poster, the neuropathological features of the resulting strain are discussed.''
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates. One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias"
Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously.
snip...
76/10.12/4.6
http://web.archive.org/web/20010305223125/www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
2026 TSE PrP
chronic wasting disease cwd, TSE, cattle, sheep, pigs, cervid, primates, humans, oh my! update 2026
Transmissible Spongiform Encephalopathy TSE
Prion Prp
Chronic Wasting Disease CWD, TSE, PrP
TSE cattle
Price of TSE Prion Poker goes up substantially, all you cattle ranchers and such, better pay close attention here...terry
"Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material."
Transmission of the chronic wasting disease agent from elk to cattle after oronasal exposure
Justin Greenlee, Jifeng Bian, Zoe Lambert, Alexis Frese, and Eric Cassmann Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
Aims: The purpose of this study was to determine the susceptibility of cattle to chronic wasting disease agent from elk.
Materials and Methods: Initial studies were conducted in bovinized mice using inoculum derived from elk with various genotypes at codon 132 (MM, LM, LL). Based upon attack rates, inoculum (10% w/v brain homogenate) from an LM132 elk was selected for transmission studies in cattle. At approximately 2 weeks of age, one wild type steer (EE211) and one steer with the E211K polymorphism (EK211) were fed 1 mL of brain homogenate in a quart of milk replacer while another 1 mL was instilled intranasally. The cattle were examined daily for clinical signs for the duration of the experiment. One steer is still under observation at 71 months post-inoculation (mpi).
Results: Inoculum derived from MM132 elk resulted in similar attack rates and incubation periods in mice expressing wild type or K211 bovine PRNP, 35% at 531 days post inoculation (dpi) and 27% at 448 dpi, respectively. Inoculum from LM132 elk had a slightly higher attack rates in mice: 45% (693 dpi) in wild type cattle PRNP and 33% (468) in K211 mice. Inoculum from LL132 elk resulted in the highest attack rate in wild type bovinized mice (53% at 625 dpi), but no K211 mice were affected at >700 days. At approximately 70 mpi, the EK211 genotype steer developed clinical signs suggestive of prion disease, depression, low head carriage, hypersalivation, and ataxia, and was necropsied. Enzyme immunoassay (IDEXX) was positive in brainstem (OD=4.00, but non-detect in retropharyngeal lymph nodes and palatine tonsil. Immunoreactivity was largely limited to the brainstem, midbrain, and cervical spinal cord with a pattern that was primarily glia-associated.
Conclusions: Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Prion Conference 2023
Transmission of the chronic wasting disease agent from elk to cattle after oronasal exposure
Conclusions: Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material.
Strain characterization of chronic wasting disease in bovine-PrP transgenic mice
Conclusions: Altogether, these results exhibit the diversity of CWD strains present in the panel of CWD isolates and the ability of at least some CWD isolates to infect bovine species. Cattle being one of the most important farming species, this ability represents a potential threat to both animal and human health, and consequently deserves further study.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
TSE sheep
ARS Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies 2025
“ARS researchers in Ames, Iowa, showed that white-tailed deer sick with scrapie from sheep can infect other deer under conditions mimicking natural exposure. Furthermore, this work shows that CWD is difficult to differentiate from WTD infected with scrapie. WTD scrapie prions accumulate in the lymphoreticular system in a manner similar to CWD, meaning that environmental contamination may occur through feces, saliva, and other body fluids of scrapie affected WTD as has been shown for CWD. The presence of WTD infected with scrapie could confound mitigation efforts for chronic wasting disease. This information informs regulatory officials, the farmed cervid industry, and officials tasked with protecting animal health such as state Departments of Agriculture, Natural Resources, or Parks and Wildlife with regard to a disease similar to CWD but arising from sheep scrapie that could be present in WTD that have contact with scrapie affected sheep and/or goats.”
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
2025 Annual Report
snip…
Accomplishments
1. 01 Determined that white-tailed deer (WTD) infected with scrapie from sheep can transmit the disease to other deer under conditions mimicking natural exposure. It has long been suggested that prion disease in deer (chronic wasting disease (CWD)) was caused by the prion agent from sheep. The prion disease that affects sheep, scrapie, has been recognized for hundreds of years. However, chronic wasting disease, a similar disease found in WTD, has only been recognized since the 1960s. ARS researchers in Ames, Iowa, showed that white-tailed deer sick with scrapie from sheep can infect other deer under conditions mimicking natural exposure. Furthermore, this work shows that CWD is difficult to differentiate from WTD infected with scrapie. WTD scrapie prions accumulate in the lymphoreticular system in a manner similar to CWD, meaning that environmental contamination may occur through feces, saliva, and other body fluids of scrapie affected WTD as has been shown for CWD. The presence of WTD infected with scrapie could confound mitigation efforts for chronic wasting disease. This information informs regulatory officials, the farmed cervid industry, and officials tasked with protecting animal health such as state Departments of Agriculture, Natural Resources, or Parks and Wildlife with regard to a disease similar to CWD but arising from sheep scrapie that could be present in WTD that have contact with scrapie affected sheep and/or goats.
snip…
https://www.ars.usda.gov/research/project/?accnNo=440677&fy=202
Component 6: Transmissible Spongiform Encephalopathies
Sheep scrapie agent can infect white-tailed deer after oronasal exposure.
The origin of chronic wasting disease (CWD) is not known, but it has many similarities to the sheep prion disease called scrapie. It has long been hypothesized that CWD arose through transmission of sheep scrapie to deer. ARS researchers in Ames, Iowa, conducted research to determine if scrapie derived from sheep could be transmitted to white-tailed deer. The deer inoculated with sheep scrapie developed clinical signs and the abnormal prion protein could be detected in a wide range of tissues. These results indicate that deer may be susceptible to sheep scrapie if exposed to the disease in natural or agricultural settings. In addition, several strong similarities between CWD in white-tailed deer and the experimental cases of scrapie in white-tailed deer suggests that it would be difficult to distinguish scrapie from CWD in deer or identify scrapie if a case occurs. This information should be considered by deer farmers for keeping their herds free from prion diseases.
https://www.ars.usda.gov/ARSUserFiles/np103/AnnualReports/NP103%20FY2023%20Annual%20Report_Final.pdf
Chronic Wasting Disease CWD vs Scrapie TSE Prion
Volume 30, Number 8—August 2024
Research
Scrapie Versus Chronic Wasting Disease in White-Tailed Deer
Zoe J. Lambert1, Jifeng Bian, Eric D. Cassmann, M. Heather West Greenlee, and Justin J. Greenlee
Author affiliations: Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA (Z.J. Lambert); US Department of Agriculture, Ames, Iowa, USA (Z.J. Lambert, J. Bian, E.D. Cassmann, J.J. Greenlee); Iowa State University, Ames (Z.J. Lambert, M.H. West Greenlee) Suggested citation for this article
Abstract
White-tailed deer are susceptible to scrapie (WTD scrapie) after oronasal inoculation with the classical scrapie agent from sheep. Deer affected by WTD scrapie are difficult to differentiate from deer infected with chronic wasting disease (CWD). To assess the transmissibility of the WTD scrapie agent and tissue phenotypes when further passaged in white-tailed deer, we oronasally inoculated wild-type white-tailed deer with WTD scrapie agent. We found that WTD scrapie and CWD agents were generally similar, although some differences were noted. The greatest differences were seen in bioassays of cervidized mice that exhibited significantly longer survival periods when inoculated with WTD scrapie agent than those inoculated with CWD agent. Our findings establish that white-tailed deer are susceptible to WTD scrapie and that the presence of WTD scrapie agent in the lymphoreticular system suggests the handling of suspected cases should be consistent with current CWD guidelines because environmental shedding may occur.
snip…
The potential for zoonoses of cervid-derived PrPSc is still not well understood (6,18,45–47); however, interspecies transmission can increase host range and zoonotic potential (48–50). Therefore, to protect herds and the food supply, suspected cases of WTD scrapie should be handled the same as cases of CWD.
https://wwwnc.cdc.gov/eid/article/30/8/24-0007_article
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
2025 Annual Report
https://transmissiblespongiformencephalopathy.blogspot.com/2025/12/ars-research-elucidating-pathobiology.html
atypical Nor-98 Scrapie USA
SATURDAY, FEBRUARY 28, 2026 atypical Nor-98, CH1641, Scrapie, TSE Prion, Update 2026 atypical Nor-98, CH1641, Scrapie, TSE Prion, Update 2026
atypical Nor-98 Scrapie Update 2025 Scrapie typical and atypical USA
FY 2023, 16,646 from sheep and 8,726 from goats.
* There have been 491 NVSL confirmed positive animals (474 classical cases – 471 sheep and 3 goats) and
19 Nor98- like cases since the beginning of RSSS. Figure 3 depicts RSSS collection sites in FY 2023.
https://www.aphis.usda.gov/sites/default/files/scrapie-annual-report.pdf
In 2023, APHIS collected samples from more than 26,000 sheep and goats for scrapie testing. Out of the total number of animals tested in 2023, no animals tested positive for classical scrapie and
one sheep tested positive for non-classical scrapie (Nor98-like)...
https://www.usda.gov/sites/default/files/documents/22-APHIS-2025-ExNotes.pdf
In 2022, APHIS collected samples from more than 23,000 sheep and goats for scrapie testing. Out of the total number of animals tested in 2022, no animals tested positive for classical scrapie and
one sheep tested positive for non-classical scrapie (Nor98-like).
https://www.usda.gov/sites/default/files/documents/23-2024-APHIS.pdf
In FY 2021, APHIS collected samples from more than 30,000 sheep and goats for scrapie testing. Out of the total number of samples processed and reported in FY 2021,
one sheep tested positive for classical scrapie and one sheep tested positive for non-classical scrapie (Nor98-like).
https://www.usda.gov/sites/default/files/documents/23-2023-APHIS.pdf
In FY 2020, APHIS collected samples from 33,839 sheep and goats for scrapie testing. This number represents sample results reported by October 15, 2020 and is expected to slightly increase as the remaining results are processed and reported. No animals tested positive for classical scrapie.
Two sheep tested positive at slaughter for non-classical scrapie (Nor98-like).
https://www.usda.gov/sites/default/files/documents/22APHIS2022Notes.pdf
In FY 2019, APHIS collected samples from 34,730 sheep and goats for scrapie testing, detecting 7 classical scrapie positive animals. Of these animals, five sheep and one goat were from a source flock in Pennsylvania that was found in August 2018, depopulated in October 2018, and tested for scrapie in November 2018. A second goat, which was from an Indiana herd, was sampled at slaughter in June 2019. The source flock completed a cleanup plan and was placed on a 5-year monitoring plan. The source herd of the positive Indiana goat no longer contained any exposed animals and was also placed on a 5-year monitoring plan. A trace-back investigation narrowed the goat’s birth herd to two possible herds. Animals in both herds tested negative for scrapie and were placed on 5-year monitoring plans. There were no classical scrapie cases detected in slaughter sheep in FY 2019.
Also in FY 2019, two sheep tested positive at slaughter for non-classical scrapie (Nor98-like) and were traced back to Colorado flocks.
https://www.usda.gov/sites/default/files/documents/20aphis2021notes.pdf
In FY 2018, APHIS collected samples from 43,625 sheep and goats for scrapie testing, detecting three positive (0.0068%) cases. These figures are based on sample submissions and testing completed by September 30, 2018. FY 2018 values are expected to change when testing is completed for all animals sampled in FY 2018.
In October 2017, a non-classical scrapie case was detected in a sheep from Virginia sampled at slaughter. As a result, the non- classical scrapie affected flock was placed on a 5-year monitoring plan.
https://www.usda.gov/sites/default/files/documents/20aphis2020notes.pdf
In FY 2016, the program identified one flock infected with classical scrapie and one infected with Nor98-like scrapie through slaughter surveillance, and two flocks infected with classical scrapie through on-farm surveillance.
An additional 10 sheep were confirmed with classical scrapie through testing of sheep depopulated from these infected flocks as part of flock clean-up activities conducted in FY 2016.
The Nor98-like scrapie affected flock will be placed on a 5-year monitoring plan.
https://www.usda.gov/sites/default/files/documents/20aphisexnotes2018.pdf
Atypical Nor-98 Scrapie TSE Prion USA State by State Update January 2021
Atypical Nor-98 Scrapie TSE Prion USA State by State Update January 2021
Nor98 cases Diagnosed in the US. To Date
Nor98 cases Diagnosed in the US.
Flock of Origin State FY
Wyoming 2007
Indiana 2007
Pennsylvania 2008
Oregon 2010
Ohio 2010
Pennsylvania 2010
Untraceable 2010
California 2011
Montana 2016
Utah 2017
Montana 2017
Virginia 2018
Colorado 2019
Colorado 2019
Wyoming 2020
Montana 2020
Pennsylvania 2021
Personal Communication from USDA et al Mon, Jan 4, 2021 11:37 am...terry
TUESDAY, SEPTEMBER 22, 2020
APHIS USDA MORE SCRAPIE ATYPICAL Nor-98 Confirmed USA September 15 2020
17 cases of the Nor98 in the USA to date, location, unknown...tss
17 Nor98-like cases since the beginning of RSSS.
https://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_report.pdf
17 Nor98-like cases since the beginning of RSSS. No animals have tested positive for classical scrapie in FY 2021.
https://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_report.pdf
TUESDAY, SEPTEMBER 22, 2020
APHIS USDA MORE SCRAPIE ATYPICAL Nor-98 Confirmed USA September 15 2020
https://scrapie-usa.blogspot.com/2020/09/aphis-usda-more-scrapie-atypical-nor-98.html
MONDAY, JULY 27, 2020
APHIS USDA Nor98-like scrapie was confirmed in a sheep sampled at slaughter in May 2020
https://nor-98.blogspot.com/2020/07/aphis-usda-nor98-like-scrapie-was.html
MONDAY, JULY 13, 2020
Efficient transmission of classical scrapie agent x124 by intralingual route to genetically susceptible sheep with a low dose inoculum
https://scrapie-usa.blogspot.com/2020/07/efficient-transmission-of-classical.html
*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics of BSE in Canada Singeltary reply ;
https://journals.plos.org/plosone/article/comment?id=10.1371/annotation/4f9be886-69fe-4c7c-922b-85b0ecbe6d53
WEDNESDAY, MAY 29, 2019
***> Incomplete inactivation of atypical scrapie following recommended autoclave decontamination procedures
https://nor-98.blogspot.com/2019/05/incomplete-inactivation-of-atypical.html
THURSDAY, DECEMBER 31, 2020
Autoclave treatment of the classical scrapie agent US No. 13-7 and experimental inoculation to susceptible VRQ/ARQ sheep via the oral route results in decreased transmission efficiency
https://scrapie-usa.blogspot.com/2020/12/autoclave-treatment-of-classical.html
Snip…see full text;
https://nor-98.blogspot.com/2021/01/atypical-nor-98-scrapie-tse-prion-usa.html
SATURDAY, FEBRUARY 28, 2026
atypical Nor-98, CH1641, Scrapie, TSE Prion, Update 2026
https://nor-98.blogspot.com/2026/02/atypical-nor-98-ch1641-scrapie-tse.html
TSE Pigs
WEDNESDAY, JANUARY 28, 2026
***> CWD TSE Prions in cervids and wild pigs in North America Preliminary Outbreak <***
Chronic wasting disease prions in cervids and wild pigs in North America Preliminary Outbreak
https://assets.publishing.service.gov.uk/media/697a3b013c71d838df6bd413/CWD_Prions_in_Cervids_and_Wild_Pigs_in_North_America.pdf
https://transmissiblespongiformencephalopathy.blogspot.com/2026/01/chronic-wasting-disease-prions-in.html
THURSDAY, JANUARY 08, 2026
Confucius Ponders, what about Wild Pigs (Sus scrofa) and CWD TSE Prion, and the Environment, what if?
Confucius Ponders, what about Wild Pigs (Sus scrofa), they can cover some distance rather quickly, what about Wild Pigs (Sus scrofa) digging up the terrain, and as they do it, what if these Wild Pigs (Sus scrofa) were exposed to CWD TSE Prion, and then they go on exposing and saturating the land with CWD TSE Prion, then the soil becomes contaminated with CWD TSE Prion, then what about the plants that grow from that soil for the decades to come, what if???
https://prpsc.proboards.com/thread/190/confucius-ponders-wild-pigs-scrofa
https://chronic-wasting-disease.blogspot.com/2026/01/confucius-ponders-what-about-wild-pigs.html
TSE Cattle
USA BSE Testing and Surveillance?
Bottom line, USA is testing so few cows for BSE (<25k tested annually)
https://www.aphis.usda.gov/livestock-poultry-disease/cattle/bse/bse-surveillance-program
BUT, even at those low testing figures, the USA did just confirm another case of BSE just here recently. Feed ban has failed terribly, and CWD is spreading in the USA, at an alarming rate. Recent transmission studies show oral transmission of CWD of Cervid to cattle. Studies also show links of sporadic CJD to BSE, Scrapie, and CWD. It’s a Whole new game of Prion poker now$$$
Wednesday, May 24, 2023
***> WAHIS, WOAH, OIE, United States of America Bovine spongiform encephalopathy Immediate notification
https://wahis.woah.org/#/in-review/5067
https://woahoie.blogspot.com/2023/05/wahis-woah-oie-united-states-of-america.html
https://prpsc.proboards.com/thread/125/wahis-woah-oie-immediate-notification
SATURDAY, MAY 20, 2023
***> Tennessee State Veterinarian Alerts Cattle Owners to Disease Detection Mad Cow atypical L-Type BSE
https://bse-atypical.blogspot.com/2023/05/tennessee-state-veterinarian-alerts.html
https://prpsc.proboards.com/thread/123/tennessee-veterinarian-alerts-cattle-confirmed
MAY 19, 2023
https://www.aphis.usda.gov/aphis/newsroom/stakeholder-info/sa_by_date/sa-2023/bse
2 weeks before the announcement of this recent mad cow case in the USA, i submitted this to the APHIS et al;
***> APPRX. 2 weeks before the recent mad cow case was confirmed in the USA, in Tennessee, atypical L-Type BSE, I submitted this to the APHIS et al;
Document APHIS-2023-0027-0001 BSE Singeltary Comment Submission May 2, 2023
''said 'burden' cost, will be a heavy burden to bear, if we fail with Bovine Spongiform Encephalopathy BSE TSE Prion disease, that is why this information collection is so critical''...
https://www.regulations.gov/comment/APHIS-2023-0027-0002
https://downloads.regulations.gov/APHIS-2023-0027-0002/attachment_1.pdf
Bovine Spongiform Encephalopathy BSE TSE Prion Origin USA?, what if?
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: Sheep are susceptible to the agent of TME by intracranial inoculation and have evidence of infectivity in lymphoid tissues
Author item CASSMANN, ERIC - Oak Ridge Institute For Science And Education (ORISE) item MOORE, SARA - Oak Ridge Institute For Science And Education (ORISE) item SMITH, JODI - Iowa State University item Greenlee, Justin
Submitted to: Frontiers in Veterinary Science Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/14/2019 Publication Date: 11/29/2019 Citation: Cassmann, E.D., Moore, S.J., Smith, J.D., Greenlee, J.J. 2019.
Sheep are susceptible to the agent of TME by intracranial inoculation and have evidence of infectivity in lymphoid tissues.
Frontiers in Veterinary Science. 6:430. https://doi.org/10.3389/fvets.2019.00430. DOI: https://doi.org/10.3389/fvets.2019.00430
Interpretive Summary: Prion diseases are protein misfolding diseases that are transmissible between animals. The outcome of prion infection is irreversible brain damage and death. Transmission can occur between animals of the same or different species, however, transmission between different species is usually less efficient due to the species barrier, which results from differences in the amino acid sequence of the prion protein between the donor and recipient species. The present work evaluated whether transmissible mink encephalopathy (TME) can infect sheep. Our results demonstrate that sheep are susceptible to the TME agent and that the TME agent has similar properties to the agent of L-type atypical bovine spongiform encephalopathy (L-BSE). This work supports the ideas that L-BSE is a possible source for TME in mink and that the practice of feeding cattle with neurologic disease to mink should be avoided. This information is important to farmers who raise cattle, sheep, or mink.
Technical Abstract: Transmissible mink encephalopathy (TME) is a food borne prion disease. Epidemiological and experimental evidence suggests similarities between the agent of TME and L-BSE. This experiment demonstrates the susceptibility of four different genotypes of sheep to the agent of TME by intracranial inoculation. The four genotypes of sheep used in this experiment had polymorphisms corresponding to codons 136 and 171 of the prion gene: VV136QQ171, AV136QQ171, AA136QQ171, and AA136QR171. All intracranially inoculated sheep without comorbidities (15/15) developed clinical scrapie and had detectable PrPSc by immunohistochemistry, western blot, and enzyme immunoassay (EIA). The mean incubation periods in TME infected sheep correlated with their relative genotypic susceptibility. There was peripheral distribution of PrPSc in the trigeminal ganglion and neuromuscular spindles; however, unlike classical scrapie and C-BSE in sheep, ovine TME did not accumulate in the lymphoid tissue. To rule out the presence of infectious, but proteinase K susceptible PrPSc, the lymph nodes of two sheep genotypes, VV136QQ171 and AA136QQ171, were bioassayed in transgenic ovinized mice. None of the mice (0/32) inoculated by the intraperitoneal route had detectable PrPSc by EIA. Interestingly, mice intracranially inoculated with RPLN tissue from a VV136QQ171 sheep were EIA positive (3/17) indicating that sheep inoculated with TME harbor infectivity in their lymph nodes. Western blot analysis demonstrated similarities in the migration patterns between ovine TME and the bovine TME inoculum. Overall, these results demonstrate that sheep are susceptible to the agent of TME, and that the tissue distribution of PrPSc in TME infected sheep is distinct from classical scrapie.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=363305
https://www.ars.usda.gov/research/publications/publication/?seqNo115=360665
https://www.ars.usda.gov/research/publications/publication/?seqNo115=373668
Previous work has shown that the Stetsonville, WI outbreak of TME could have been precipitated by feeding mink a downer cow with atypical BSE; therefore, it very well may have originated from a cow with L-BSE. The agent of TME appears to remain stable, and it has a high transmission efficiency after a sequence of interspecies transmission events. Although C-BSE is the archetypal foodborne TSE, our findings indicate that L-BSE and bTME have greater transmission efficiencies in bovinized mice. Previous work has demonstrated that L-BSE also is more virulent than C-BSE in mice expressing the human prion protein [46, 55]. Although the documented incidence of L-BSE is low, the propensity of L-BSE and the TME agent to cross species barriers support the continued monitoring for atypical BSE.
https://bmcvetres.biomedcentral.com/articles/10.1186/s12917-020-02611-0
***>This work supports the ideas that L-BSE is a possible source for TME in mink and that the practice of feeding cattle with neurologic disease to mink should be avoided. This information is important to farmers who raise cattle, sheep, or mink.<***
1985
Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.
snip...
The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...
https://web.archive.org/web/20090506002258/http://www.bseinquiry.gov.uk/files/mb/m09/tab05.pdf
https://web.archive.org/web/20090506001031/http://www.bseinquiry.gov.uk/files/mb/m09a/tab01.pdf
https://web.archive.org/web/20090506024922/http://www.bseinquiry.gov.uk/files/yb/1987/06/10004001.pdf
Re-USA BSE Surveillance, BSE Testing, BSE Feed Regulation (21 CFR 589.2000), SRMs, and CWD
“Conclusion: These results demonstrate the oral transmission potential of atypical BSE in cattle. Surprisingly, regardless of which atypical type of BSE was used for P1 oral challenge, Prpsc in the P2 animals acquired biochemical characteristics similar to that of Prps in C-BSE, suggesting atypical BSE as a possible origin of C-BSE in UK.”
Abstract for Prion 2023
Title: Transmission of atypical BSE: a possible origin of Classical BSE in cattle…end…TSS
TSE cervid
PLoS One. 2020 Aug 20;15(8):e0237410. doi: 10.1371/journal.pone.0237410. eCollection 2020.
Very low oral exposure to prions of brain or saliva origin can transmit chronic wasting disease
Nathaniel D Denkers 1 , Clare E Hoover 2 , Kristen A Davenport 3 , Davin M Henderson 1 , Erin E McNulty 1 , Amy V Nalls 1 , Candace K Mathiason 1 , Edward A Hoover 1
PMID: 32817706 PMCID: PMC7446902 DOI: 10.1371/journal.pone.0237410
Abstract
The minimum infectious dose required to induce CWD infection in cervids remains unknown, as does whether peripherally shed prions and/or multiple low dose exposures are important factors in CWD transmission. With the goal of better understand CWD infection in nature, we studied oral exposures of deer to very low doses of CWD prions and also examined whether the frequency of exposure or prion source may influence infection and pathogenesis. We orally inoculated white-tailed deer with either single or multiple divided doses of prions of brain or saliva origin and monitored infection by serial longitudinal tissue biopsies spanning over two years. We report that oral exposure to as little as 300 nanograms (ng) of CWD-positive brain or to saliva containing seeding activity equivalent to 300 ng of CWD-positive brain, were sufficient to transmit CWD disease. This was true whether the inoculum was administered as a single bolus or divided as three weekly 100 ng exposures. However, when the 300 ng total dose was apportioned as 10, 30 ng doses delivered over 12 weeks, no infection occurred. While low-dose exposures to prions of brain or saliva origin prolonged the time from inoculation to first detection of infection, once infection was established, we observed no differences in disease pathogenesis. These studies suggest that the CWD minimum infectious dose approximates 100 to 300 ng CWD-positive brain (or saliva equivalent), and that CWD infection appears to conform more with a threshold than a cumulative dose dynamic.
Snip…
Discussion
As CWD expands across North America and Scandinavia, how this disease is transmitted so efficiently remains unclear, given the low concentrations of prions shed in secretions and excretions [13, 14]. The present studies demonstrated that a single oral exposure to as little as 300nmg of CWD-positive brain or equivalent saliva can initiate infection in 100% of exposed white-tailed deer. However, distributing this dose as 10, 30 ng exposures failed to induce infection. Overall, these results suggest that the minimum oral infectious exposure approaches 100 to 300 ng of CWD-positive brain equivalent. These dynamics also invite speculation as to whether potential infection co-factors, such as particle binding [46, 47] or compromises in mucosal integrity may influence infection susceptibility, as suggested from two studies in rodent models [48, 49].
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237410
PRION 2023 CONTINUED;
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Prion 2023 Experimental Oronasal Inoculation of the Chronic Wasting Disease Agent into White Tailed Deer
Author list: Sarah Zurbuchena,b , S. Jo Moorea,b , Jifeng Biana , Eric D. Cassmanna , and Justin J. Greenleea . a. Virus and Prion Research Unit, National Animal Disease Center, ARS, United States Department of Agriculture, Ames, IA, US b. Oak Ridge Institute for Science and Education (ORISE), U.S. Department of Energy, Oak Ridge, TN, United States
Aims: The purpose of this experiment was to determine whether white-tailed deer (WTD) are susceptible to inoculation of chronic wasting disease (CWD) via oronasal exposure.
Materials and methods: Six male, neutered WTD were oronasally inoculated with brainstem material (10% w/v) from a CWD-positive wild-type WTD. The genotypes of five inoculated deer were Q95/G96 (wild-type). One inoculated deer was homozygous S at codon 96 (96SS). Cervidized (Tg12; M132 elk PrP) mice were inoculated with 1% w/v brainstem homogenate from either a 96GG WTD (n=10) or the 96SS WTD (n=10).
Results: All deer developed characteristic clinical signs of CWD including weight loss, regurgitation, and ataxia. The 96SS individual had a prolonged disease course and incubation period compared to the other deer. Western blots of the brainstem on all deer yielded similar molecular profiles. All deer had widespread lymphoid distribution of PrPCWD and neuropathologic lesions associated with transmissible spongiform encephalopathies. Both groups of mice had a 100% attack rate and developed clinical signs, including loss of body condition, ataxia, and loss of righting reflex. Mice inoculated with material from the 96SS deer had a significantly shorter incubation period than mice inoculated with material from 96GG deer (Welch two sample T-test, P<0.05). Serial dilutions of each inocula suggests that differences in incubation period were not due to a greater concentration of PrPCWD in the 96SS inoculum. Molecular profiles from western blot of brain homogenates from mice appeared similar regardless of inoculum and appear similar to those of deer used for inoculum.
Conclusions: This study characterizes the lesions and clinical course of CWD in WTD inoculated in a similar manner to natural conditions. It supports previous findings that 96SS deer have a prolonged disease course. Further, it describes a first pass of inoculum from a 96SS deer in cervidized mice which shortened the incubation period.
Funded by: This research was funded in its entirety by congressionally appropriated funds to the United States Department of Agriculture, Agricultural Research Service. The funders of the work did not influence study design, data collection, analysis, decision to publish, or preparation of the manuscript.
Acknowledgement: We thank Ami Frank and Kevin Hassall for their technical contributions to this project.
=====end
PRION 2023 CONTINUED;
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Camel Prion Disease PrP
Thursday, February 19, 2026
Identification of Camel Prion Disease in Tunisia: evidence of an emerging prion disease in North Africa
https://camelusprp.blogspot.com/2026/02/identification-of-camel-prion-disease.html
Raccoon TSE PrP
The chronic wasting disease agent from white-tailed deer is highly infectious to humanized mice after passage through raccoons
https://www.ars.usda.gov/research/publications/publication/?seqNo115=400777
CWD TSE primates and humans
***> Human CWD TSE PrP, what if?
the problem is, to date, there is NO diagnostic criteria set in stone that would confirm a case of human Cwd, like there was with nvCJD (my Mom died from confirmed hvCJD a rare strain of the infamous sporadic CJDs with new strains mounting, sporadic CJD simply means ‘unknown’, IT DOES NOT MEAN 85%+ SPORADIC CJD IS ALL SPONTANEOUS, that’s all iatrogenic CJD is sporadic CJD, until the iatrogenic event is detected, confirmed, traced back, confirmed, put I to the academic domain, and finally, if your lucky, finally published to the media, and finally the public domain.) sorry, I got off course…but let me perfectly clear here, all science to date shows, Human CWD will not look like New Variant Creutzfeldt Jakob disease nvCJD. CWD to humans will look like some variant of sporadic Creutzfeldt Jakob Disease. And here me out very clearly, and this is from the to TSE Prion Gods themselves, old correspondence from way back during my investigations early BSE nvCJD days…2002
“Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.”
*** now, let’s see what the authors said about this casual link, personal communications years ago, and then the latest on the zoonotic potential from CWD to humans from the TOKYO PRION 2016 CONFERENCE.
see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ????
“Our conclusion stating that we found no strong evidence of CWD transmission to humans”
Subject: CWD aka MAD DEER/ELK TO HUMANS ???
Date: September 30, 2002 at 7:06 am PST
From: "Belay, Ermias"
To: Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"
Sent: Monday, September 30, 2002 9:22 AM
Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Dear Sir/Madam, In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD.. That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091).
Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.
Ermias Belay, M.D. Centers for Disease Control and Prevention
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM .......snip........end..............TSS
-----Original Message-----
From:
Sent: Sunday, September 29, 2002 10:15 AM
To: rr26k@nih.gov; rrace@niaid.nih.gov; ebb8@CDC.GOV
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM .......snip........end..............TSS
“regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD”
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ …
######## Bovine Spongiform Encephalopathy <BSE-L@UNI-KARLSRUHE.DE> #########
Dear Terry,
An excellent piece of review as this literature is desparately difficult to get back from Government sites. What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported.
Well, if you dont look adequately like they are in USA currenly then you wont find any!
Steve Dealler
########### http://mailhost.rz.uni-karlsruhe.de/warc/bse-l.html ############
Subject: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
From: "Terry S. Singeltary Sr." <flounder@WT.NET>
Reply To: Bovine Spongiform Encephalopathy <BSE-L@UNI-KARLSRUHE.DE>
Date: Thu, 17 Oct 2002 17:04:51 -0700
snip...
''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994
snip...see full report ;
http://web.archive.org/web/20090506050043/http://www.bseinquiry.gov.uk/files/yb/1994/08/00004001.pdf
http://web.archive.org/web/20090506050007/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
http://web.archive.org/web/20090506050244/http://www.bseinquiry.gov.uk/files/yb/1994/07/00001001.pdf
Stephen Dealler is a consultant medical microbiologist deal@airtime.co.uk BSE Inquiry Steve Dealler Management In Confidence BSE: Private Submission of Bovine Brain Dealler
snip...end
########### http://mailhost.rz.uni-karlsruhe.de/warc/bse-l.html ############
***> ''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
GAME FARM INDUSTRY WANTS TO COVER UP FINDINGS OF INCREASE RISK TO CJD FROM CERVID
BSE INQUIRY
CJD9/10022
October 1994
Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane
BerksWell Coventry CV7 7BZ
Dear Mr Elmhirst,
CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT
Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.
The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended.. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.
The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.
The statistical results regarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.
I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.
http://web.archive.org/web/20030511010117/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
MONDAY, FEBRUARY 25, 2019
***> MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019
https://bseinquiry.blogspot.com/2019/02/mad-dogs-and-englishmen-bse-scrapie-cwd.html
*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***
http://www.tandfonline.com/doi/full/10.4161/pri.28124?src=recsys
http://www.tandfonline.com/doi/pdf/10.4161/pri.28124?needAccess=true
https://wwwnc.cdc.gov/eid/article/20/1/13-0858_article
So, this is what we leave our children and grandchildren?
CDC CWD TSE Prion Update 2025
KEY POINTS
Chronic wasting disease affects deer, elk and similar animals in the United States and a few other countries.
The disease hasn't been shown to infect people.
However, it might be a risk to people if they have contact with or eat meat from animals infected with CWD.
https://www.cdc.gov/chronic-wasting/about/index.html
Prions in Muscles of Cervids with Chronic Wasting Disease, Norway
Volume 31, Number 2—February 2025
Research
Prions in Muscles of Cervids with Chronic Wasting Disease, Norway
Snip…
In summary, the results of our study indicate that prions are widely distributed in peripheral and edible tissues of cervids in Norway, including muscles. This finding highlights the risk of human exposure to small amounts of prions through handling and consuming infected cervids.
Appendix
https://wwwnc.cdc.gov/eid/article/31/2/24-0903-app1.pdf
https://wwwnc.cdc.gov/eid/article/31/2/24-0903_article
Volume 31, Number 2—February 2025
Dispatch
Detection of Chronic Wasting Disease Prions in Raw, Processed, and Cooked Elk Meat, Texas, USA
Snip…
Of note, our data show that exposure to high temperatures used to cook the meat increased the availability of prions for in vitro amplification. Considering the potential implications in food safety and public health, we believe that the findings described in this study warrant further research. Our results suggest that although the elk meat used in this study resisted different manipulations involved in subsequent consumption by humans, their zoonotic potential was limited. Nevertheless, even though no cases of CWD transmission to human have been reported, the potential for human infection is still unclear and continued monitoring for zoonotic potential is warranted.
https://wwwnc.cdc.gov/eid/article/31/2/24-0906_article
Detection of chronic wasting disease prions in processed meats
Results: Our results show positive prion detection in all the samples analyzed using deer and elk substrates. Surprisingly, cooked meats displayed increased seeding activities. This data suggests that CWD-prions are available to people even after meats are processed and cooked.
Conclusions: These results suggest CWD prions are accessible to humans through meats, even after processing and cooking. Considering the fact that these samples were collected from already processed specimens, the availability of CWD prions to humans is probably underestimated.
"Our results show positive prion detection in all the samples analyzed using deer and elk substrates. Surprisingly, cooked meats displayed increased seeding activities."
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
DETECTION OF CHRONIC WASTING DISEASE PRIONS IN PROCESSED MEATS.
In this study, we analyzed different processed meats derived from a pre-clinical, CWD-positive free-ranging elk. Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats. CWD-prion presence in these products were assessed by PMCA using deer and elk substrates. Our results show positive prion detection in all products. To confirm the resilience of CWD-prions to traditional cooking methods, we grilled and boiled the meat products and evaluated them for any remnant PMCA seeding activity. Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking. Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats.
CWD-prion presence in these products were assessed by PMCA using deer and elk substrates.
Our results show positive prion detection in all products.
Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking.
Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true
Transmission of prion infectivity from CWD-infected macaque tissues to rodent models demonstrates the zoonotic potential of chronic wasting disease.
Further passage to cervidized mice revealed transmission with a 100% attack rate.
Our findings demonstrate that macaques, considered the best model for the zoonotic potential of prions, were infected upon CWD challenge, including the oral one.
The disease manifested as atypical in macaques and initial transgenic mouse transmissions, but with infectivity present at all times, as unveiled in the bank vole model with an unusual tissue tropism.
Epidemiologic surveillance of prion disease among cervid hunters and people likely to have consumed venison contaminated with chronic wasting disease
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https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true
Fortuitous generation of a zoonotic cervid prion strain
Aims: Whether CWD prions can infect humans remains unclear despite the very substantial scale and long history of human exposure of CWD in many states or provinces of USA and Canada. Multiple in vitro conversion experiments and in vivo animal studies indicate that the CWD-to-human transmission barrier is not unbreakable. A major long-term public health concern on CWD zoonosis is the emergence of highly zoonotic CWD strains. We aim to address the question of whether highly zoonotic CWD strains are possible.
Materials and Methods: We inoculated several sCJD brain samples into cervidized transgenic mice (Tg12), which were intended as negative controls for bioassays of brain tissues from sCJD cases who had potentially been exposed to CWD. Some of the Tg12mice became infected and their brain tissues were further examined by Western blot as well as serial passages in humanized or cervidized mice.
Results: Passage of sCJDMM1 in transgenic mice expressing elk PrP (Tg12) resulted in a “cervidized” CJD strain that we termed CJDElkPrP. We observed 100% transmission of the original CJDElkPrP in transgenic mice expressing human PrP. We passaged CJDElkPrP two more times in the Tg12mice. We found that such second and third passage CJDElkPrP prions retained 100% transmission rate in the humanized mice, despite that the natural elk CWD isolates and CJDElkPrP share the same elk PrP sequence. In contrast, we and others found zero or poor transmission of natural elk CWD isolates in humanized mice.
Conclusions: Our data indicate that highly zoonotic cervid prion strains are not only possible but also can retain zoonotic potential after serial passages in cervids, suggesting a very significant and serious long-term risk of CWD zoonosis given that the broad and continuing spread of CWD prions will provide fertile grounds for the emergence of zoonotic CWD strains over time.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Samia Hannaoui1 · Irina Zemlyankina1 · Sheng Chun Chang1 · Maria Immaculata Arifn1 · Vincent Béringue2 · Debbie McKenzie3 · Hermann M. Schatzl1 · Sabine Gilch1
Received: 24 May 2022 / Revised: 5 August 2022 / Accepted: 7 August 2022
© The Author(s) 2022
Abstract
Prions cause infectious and fatal neurodegenerative diseases in mammals. Chronic wasting disease (CWD), a prion disease of cervids, spreads efficiently among wild and farmed animals. Potential transmission to humans of CWD is a growing concern due to its increasing prevalence. Here, we provide evidence for a zoonotic potential of CWD prions, and its probable signature using mice expressing human prion protein (PrP) as an infection model. Inoculation of these mice with deer CWD isolates resulted in atypical clinical manifestation with prion seeding activity and efficient transmissible infectivity in the brain and, remarkably, in feces, but without classical neuropathological or Western blot appearances of prion diseases. Intriguingly, the protease-resistant PrP in the brain resembled that found in a familial human prion disease and was transmissible upon second passage. Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
Keywords Chronic wasting disease · CWD · Zoonotic potential · Prion strains · Zoonotic prions
HIGHLIGHTS OF THIS STUDY
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Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
In this study, we evaluated the zoonotic potential of CWD using a transgenic mouse model overexpressing human M129-PrPC (tg650 [12]). We inoculated tg650mice intracerebrally with two deer CWD isolates, Wisc-1 and 116AG [22, 23, 27, 29]. We demonstrate that this transgenic line was susceptible to infection with CWD prions and displayed a distinct leading clinical sign, an atypical PrPSc signature and unusual fecal shedding of infectious prions. Importantly, these prions generated by the human PrP transgenic mice were transmissible upon passage. Our results are the first evidence of a zoonotic risk of CWD when using one of the most common CWD strains, Wisc-1/CWD1 for infection. We demonstrated in a human transgenic mouse model that the species barrier for transmission of CWD to humans is not absolute. The fact that its signature was not typical raises the questions whether CWD would manifest in humans as a subclinical infection, whether it would arise through direct or indirect transmission including an intermediate host, or a silent to uncovered human-to-human transmission, and whether current detection techniques will be suffcient to unveil its presence.
Our findings strongly suggest that CWD should be regarded as an actual public health risk. Here, we use humanized mice to show that CWD prions can cross the species barrier to humans, and remarkably, infectious prions can be excreted in feces.
Our results indicate that if CWD crosses the species-barrier to humans, it is unlikely to resemble the most common forms of human prion diseases with respect to clinical signs, tissue tropism and PrPSc signature. For instance, PrPSc in variable protease-sensitive prionopathy (VPSPr), a sporadic form of human prion disease, and in the genetic form Gerstmann-Sträussler-Scheinker syndrome (GSS) is defined by an atypical PK-resistant PrPSc fragment that is non-glycosylated and truncated at both C- and N-termini, with a molecular weight between 6 and 8 kDa [24, 44–46]. These biochemical features are unique and distinctive from PrPSc (PrP27-30) found in most other human or animal prion disease. The atypical PrPSc signature detected in brain homogenate of tg650 mice #321 (1st passage) and #3063 (2nd passage), and the 7–8 kDa fragment (Figs. 2, 4) are very similar to that of GSS, both in terms of migration profile and the N-terminal cleavage site.
CWD in humans might remain subclinical but with PrPSc deposits in the brain with an unusual morphology that does not resemble the patterns usually seen in different prion diseases (e.g., mouse #328; Fig. 3), clinical with untraceable abnormal PrP (e.g., mouse #327) but still transmissible and uncovered upon subsequent passage (e.g., mouse #3063; Fig. 4), or prions have other reservoirs than the usual ones, hence the presence of infectivity in feces (e.g., mouse #327) suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.
“suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.”
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Supplementary Information The online version contains supplementary material available at
https://doi.org/10.1007/s00401-022-02482-9
snip...see full text;
https://link.springer.com/article/10.1007/s00401-022-02482-9
https://link.springer.com/content/pdf/10.1007/s00401-022-02482-9.pdf
Macaque tissues to rodent models demonstrates the zoonotic potential of chronic wasting disease.
Samia Hannaoui1,2, Ginny Cheng1,2, Wiebke Wemheuer3, Walter Schulz-Schaeffer3, Sabine Gilch1,2, Hermann Schatzl1,2 1University of Calgary, Calgary, Canada. 2Calgary Prion Research Unit, Calgary, Canada. 3Institute of Neuropathology, Medical Faculty, Saarland University, Homburg/Saar, Germany
Snip…
***> Further passage to cervidized mice revealed transmission with a 100% attack rate.
***> Our findings demonstrate that macaques, considered the best model for the zoonotic potential of prions, were infected upon CWD challenge, including the oral one.
****> The disease manifested as atypical in macaques and initial transgenic mouse transmissions, but with infectivity present at all times, as unveiled in the bank vole model with an unusual tissue tropism.
***> Epidemiologic surveillance of prion disease among cervid hunters and people likely to have consumed venison contaminated with chronic wasting disease
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https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true
Transmission of Cervid Prions to Humanized Mice Demonstrates the Zoonotic Potential of CWD
Samia Hannaouia, Irina Zemlyankinaa, Sheng Chun Changa, Maria Immaculata Arifina, Vincent Béringueb, Debbie McKenziec, Hermann M. Schatzla, and Sabine Gilcha
Results: Here, we provide the strongest evidence supporting the zoonotic potential of CWD prions, and their possible phenotype in humans. Inoculation of mice expressing human PrPCwith deer CWD isolates (strains Wisc-1 and 116AG) resulted in atypical clinical manifestations in > 75% of the mice, with myoclonus as leading clinical sign. Most of tg650brain homogenates were positive for seeding activity in RT-QuIC. Clinical disease and presentation was transmissible to tg650mice and bank voles. Intriguingly, protease-resistant PrP in the brain of tg650 mice resembled that found in a familial human prion disease and was transmissible upon passage. Abnormal PrP aggregates upon infection with Wisc-1 were detectable in thalamus, hypothalamus, and midbrain/pons regions.
Unprecedented in human prion disease, feces of CWD-inoculated tg650 mice harbored prion seeding activity and infectious prions, as shown by inoculation of bank voles and tg650 with fecal homogenates.
Conclusions: This is the first evidence that CWD can infect humans and cause disease with a distinctive clinical presentation, signature, and tropism, which might be transmissible between humans while current diagnostic assays might fail to detect it. These findings have major implications for public health and CWD-management.
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
18. Zoonotic potential of moose-derived chronic wasting disease prions after adaptation in intermediate species
Tomás Barrioa, Jean-Yves Doueta, Alvina Huora, Séverine Lugana, Naïma Arona, Hervé Cassarda, Sylvie L. Benestadb, Juan Carlos Espinosac, Juan María Torresc, Olivier Andréolettia
aUnité Mixte de Recherche de l’Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement 1225 Interactions Hôtes-Agents Pathogènes, École Nationale Vétérinaire de Toulouse, 31076 Toulouse, France; bNorwegian Veterinary Institute, P.O. Box 64, NO-1431 Ås, Norway; cCentro de Investigación en Sanidad Animal (CISA-INIA), 28130, Valdeolmos, Madrid, Spain
Aims: Chronic wasting disease (CWD) is an emerging prion disease in Europe. To date, cases have been reported in three Nordic countries and in several species, including reindeer (Rangifer tarandus), moose (Alces alces) and red deer (Cervus elaphus). Cumulating data suggest that the prion strains responsible for the European cases are distinct from those circulating in North America. The biological properties of CWD prions are still poorly documented, in particular their spillover and zoonotic capacities. In this study, we aimed at characterizing the interspecies transmission potential of Norwegian moose CWD isolates.
Materials and Methods: For that purpose, we performed experimental transmissions in a panel of transgenic models expressing the PrPC sequence of various species.
Results: On first passage, one moose isolate propagated in the ovine PrPC-expressing model (Tg338). After adaptation in this host, moose CWD prions were able to transmit in mice expressing either bovine or human PrPC with high efficacy.
Conclusions: These results suggest that CWD prions can acquire enhanced zoonotic properties following adaptation in an intermediate species.
Funding
Grant number: AAPG2020 EU-CWD, ICRAD2020 TCWDE, NRC2022 NorCWD
Acknowledgement
https://www.tandfonline.com/doi/full/10.1080/19336896.2024.2424058
“ After adaptation in this host, moose CWD prions were able to transmit in mice expressing either bovine or human PrPC with high efficacy.”
TUESDAY, APRIL 07, 2026
APHIS USDA Captive CWD Herds Update by State March 2026
CHRONIC WASTING DISEASE CASES
Updated March 2026
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
Remember, a quarantined captive CWD Herd, is a ticking environmental time bomb just waiting to go off, think Chernobyl, the longer held in quarantine, the greater chance of environmental spread of CWD. litigation of CWD can take what seems to be an eternity, and CWD TSE Prion saturation into the environment grows each day left in quarantine. …terry
TUESDAY, APRIL 07, 2026
APHIS USDA Captive CWD Herds Update by State March 2026
https://chronic-wasting-disease.blogspot.com/2026/04/aphis-usda-captive-cwd-herds-update-by.html
Texas Chronic Wasting Disease CWD TSE Prion Progression 2012 to 2026, Positives to date 1282 confirmed
https://chronic-wasting-disease.blogspot.com/2026/03/texas-chronic-wasting-disease-cwd-tse.html
Control of Chronic Wasting Disease OMB Control Number: 0579-0189APHIS-2021-0004 Singeltary Submission
https://www.regulations.gov/comment/APHIS-2021-0004-0002
https://downloads.regulations.gov/APHIS-2021-0004-0002/attachment_1.pdf
Docket No. APHIS-2018-0011 Chronic Wasting Disease Herd Certification
https://www.regulations.gov/document/APHIS-2018-0011-0003
https://downloads.regulations.gov/APHIS-2018-0011-0003/attachment_1.pdf
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed
PUBLIC SUBMISSION
Comment from Terry Singeltary Sr.
Posted by the Food and Drug Administration on May 17, 2016 Comment
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission
https://www.regulations.gov/comment/FDA-2003-D-0432-0011
https://www.regulations.gov/docket/FDA-2003-D-0432
now, where was i?.. yes, genetic manipulation of the cervid to be less resistant to cwd, what could go wrong?
what im trying to converse here is, putting the TSE PrP cart before the cwd horse, BAD IDEA! TSE PrP properties can change when trying to manipulate genes, it’s just the nature of the beast. we know now, CWD will transmit to cattle, sheep, pigs, primates, and the only reason no documented link to humans has not been documented to date, there is no definitive diagnostic criteria set in stone as to make that definitive diagnosis, because imho, all studies to date show any link to cwd for humans shows a sporadic strain of sorts, study after study, NOT BSE, nvCJD. wild feral pigs have already shown susceptibility to CWD, in fact, the EU just released,, Chronic wasting disease prions in cervids and wild pigs in North America Preliminary Outbreak (see below). but science has shown, manipulating genes to be less resistant to TSE Prion, can have unforeseen circumstances, circumstances that are not always good, and in doing so, before extensive research, by releasing said genetic manipulated Cervid into the wild, you risk opening up a can of holy hell, you can’t put back in a can. why take that risk, it’s a bandaid approach to something that needs a tourniquet.
cwd can travel at 50 mph or so, FROM THE BACK OF A TRUCK, TRAILER!
stop trucking CWD!
Texas CWD Detected Mason County, Medina County, WTD Breeder, and Duval County, WTD Hunt, 2026
APHIS USDA Captive CWD Herds Update by State March 2026 Update
CHRONIC WASTING DISEASE CASES
Date of Index Case Confirmation Index Case State County Species Herd Type HCP Enrolled HCP Certified Number of Animals Herd Status
3/5/2026 2 YR Male PA Huntingdon WTD Elk Sika Hunt No No 100+ Quarantine
3/5/2026 1.5 YR Male TX Mason WTD Breeder No No 73 Quarantine
3/5/2026 2.5 YR Female TX Medina WTD Breeder No No 90 Quarantine
2/20/2026 2.75 YR Male MI Calhoun WTD Breeder Yes Yes 24 Quarantine
2/17/2026 2.5 YR Male KS Osage Axis Breeder No No 21 Quarantine
2/12/2026 3.5 YR TX Duval WTD Hunt No No ukn Quarantine
1/22/2026 3 YR Male PA Butler Elk Breeding Yes Yes 30 Quarantine
12/16/2025 Adults Male PA Indiana WTD elk Red deer Fallow Hunt No No ukn Quarantine
12/15/2025 3 YR Male PA Warren WTD Breeder No No >100 Quarantine
12/15/2025 4.5 YR Male PA Lycoming WTD ELK Hunt No No >100 Quarantine
12/15/2025 2.5 YR Male PA Juniata WTD Hobby No No 4 Quarantine
Updated March 2026
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
https://chronic-wasting-disease.blogspot.com/2026/04/aphis-usda-captive-cwd-herds-update-by.html
TUESDAY, APRIL 07, 2026
APHIS USDA Captive CWD Herds Update by State March 2026 Update
APHIS USDA Captive CWD Herds Update by State March 2026 Update
CHRONIC WASTING DISEASE CASES
Date of Index Case Confirmation Index Case State County Species Herd Type HCP Enrolled HCP Certified Number of Animals Herd Status
3/5/2026 2 YR Male PA Huntingdon WTD Elk Sika Hunt No No 100+ Quarantine
3/5/2026 1.5 YR Male TX Mason WTD Breeder No No 73 Quarantine
3/5/2026 2.5 YR Female TX Medina WTD Breeder No No 90 Quarantine
2/20/2026 2.75 YR Male MI Calhoun WTD Breeder Yes Yes 24 Quarantine
2/17/2026 2.5 YR Male KS Osage Axis Breeder No No 21 Quarantine
2/12/2026 3.5 YR TX Duval WTD Hunt No No ukn Quarantine
1/22/2026 3 YR Male PA Butler Elk Breeding Yes Yes 30 Quarantine
12/16/2025 Adults Male PA Indiana WTD elk Red deer Fallow Hunt No No ukn Quarantine
12/15/2025 3 YR Male PA Warren WTD Breeder No No >100 Quarantine
12/15/2025 4.5 YR Male PA Lycoming WTD ELK Hunt No No >100 Quarantine
12/15/2025 2.5 YR Male PA Juniata WTD Hobby No No 4 Quarantine
Updated March 2026
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
https://chronic-wasting-disease.blogspot.com/2026/04/aphis-usda-captive-cwd-herds-update-by.html
11/1/2025 ukn TX Limestone WTD Hunt No No 132 Quarantine
10/27/2025 3 YR Make WI Richland WTD Breeder Yes Yes ukn Quarantine
10/9/2025 2 YR Female TX Duvall WTD Breeder No No 94+ Quarantine
10/9/2025 2 YR Male PA Franklin WTD Breeder No No 23 Quarantine
10/8/2025 3.5 YR Male PA Huntingdon WTD Hobby No No 2 Quarantine
10/8/2025 3 YR Male WI Portage WTD Fallow Hunt No No 132 Quarantine
9/26/2025 8.5 YR Female TX Navaro WTD Breeder No No 650 Quarantine
9/16/2025 3 YR Female PA Dauphin WTD Breeder Yes Yes 85 Quarantine
9/5/2025 3 YR Male TX Duvall WTD Breeder No No 107+ Quarantine
8/6/2025 Adult Female PA Fulton WTD Breeder No No 14 Quarantine
7/21/2025 4 YR Female PA Bedford WTD Breeder No No 34 Quarantine
Updated December 2025 CHRONIC WASTING DISEASE CASES
6/3/2025 11 YR Female PA Blair WTD Breeder No No 45 Quarantine
6/3/2025 8 YR Female PA Bedford WTD Breeder No No 6 Quarantine
5/16/2025 5.5 YR Female WI Rock WTD Breeder No No ~46 Quarantine
5/14/2025 3 YR Female UT Weber Elk Hunt No No ukn Quarantine
4/30/2025 4.5 YR Male PA Jefferson WTD Hunt No No 36 Depopulated
4/18/2025 10+ YR Ukn TX Zavala WTD Hunt No No 190 Quarantine
4/9/2025 6 YR Male MI Montcalm WTD Breeder No No 86 Quarantine
3/28/2025 3.5 YR Male PA Huntingdon WTD Hobby No No 2 Quarantine
3/28/2025 3.5 YR Female PA Wayne Red Deer Hunt No no 31 Depopulated
2/26/2025 1.5 YR Male TX Kauffman WTD Breeder Yes Yes 400 Quarantine
2/26/2025 3.5 Yr Male PA Lancaster WTD Breeder Yes Yes 105 Quarantine
2/21/2025 4 YR Male CO Montrose Elk Hunt No No 97 Quarantine
Updated December 2025 CHRONIC WASTING DISEASE CASES
2/21/2025 7 YR Female MI Osceola WTD Hunt No No 201 Quarantine
2/10/2025 3.5 YR Male PA Perry WTD Hunt No No 15 Quarantine
1/7/2025 4 YR Female CO Mesa Elk Hunt No No 217 Quarantine
1/7/2025 2 YR Male UT Duchesne Elk Hunt No No 0 No animals
snip…see more;
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
Remember, a quarantined captive CWD Herd, is a ticking environmental time bomb just waiting to go off, think Chernobyl, the longer held in quarantine, the greater chance of environmental spread of CWD. litigation of CWD can take what seems to be an eternity, and CWD TSE Prion saturation into the environment grows each day left in quarantine. …terry
APHIS USDA Captive CWD Herds Update by State December 2025 Update
https://chronic-wasting-disease.blogspot.com/2025/12/aphis-usda-captive-cwd-herds-update-by.html
https://prpsc.proboards.com/thread/187/aphis-captive-herds-update-december
THURSDAY, MARCH 26, 2026
Texas Chronic Wasting Disease CWD TSE Prion Progression 2012 to 2026, Positives to date 1282 confirmed
https://chronic-wasting-disease.blogspot.com/2026/03/texas-chronic-wasting-disease-cwd-tse.html
TPW Commission Meeting CWD TSE PrP Transcript January 22, 2026 TEXAS PARKS AND WILDLIFE COMMISSION
Singeltary letter of concern on CWD 2026 submission
https://chronic-wasting-disease.blogspot.com/2026/03/tpw-commission-meeting-transcript-cwd.html
https://prpsc.proboards.com/thread/213/texas-chronic-wasting-disease-science
TPWD Commission Agenda Item 6 January 22, 2026
Chronic Wasting Disease Detection and Response Rules Recommended Adoption of Proposed Changes
https://prpsc.proboards.com/thread/192/tpwd-commission-agenda-january-detection
https://chronic-wasting-disease.blogspot.com/2026/01/tpwd-chronic-wasting-disease-detection.html
Texas Chronic Wasting Disease CWD TSE Prion Dashboard Update August 2025
SEE NEW DASHBOARD FOR CWD POSITIVES!
https://experience.arcgis.com/experience/8f6c27330c444a19b4b57beb7ffabb8b/page/Dashboard#data_s=id%3AdataSource_3-1966d773e34-layer-10%3A29
Texas CWD total by calendar years
https://chronic-wasting-disease.blogspot.com/2024/12/texas-cwd-tse-prion-positive-samples-by.html
https://tpwd.texas.gov/huntwild/wild/diseases/cwd/positive-cases/listing-cwd-cases-texas.phtml#texasCWD
Counties where CWD Exposed Deer were Released
https://tpwd.texas.gov/documents/257/CWD-Trace-OutReleaseSites.pdf
Number of CWD Exposed Deer Released by County
https://tpwd.texas.gov/documents/258/CWD-Trace-OutReleaseSites-NbrDeer.pdf
CWD Status Captive Herds
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
Texas CWD total by calendar years
https://chronic-wasting-disease.blogspot.com/2024/12/texas-cwd-tse-prion-positive-samples-by.html
https://prpsc.proboards.com/thread/178/texas-game-wardens-conclusion-ghost
https://tpwd.texas.gov/huntwild/wild/diseases/cwd/positive-cases/listing-cwd-cases-texas.phtml#texasCWD
Trucking CWD TSE Prion
Chronic Wasting Disease CWD TSE Prion of Cervid
“CWD spreads among wild populations at a relatively slow rate, limited by the natural home range and dispersed nature of wild animals.”
NOW HOLD YOUR HORSES, Chronic Wasting Disease CWD of Cervid can spread rather swiftly, traveling around 50 MPH, from the back of truck and trailer, and Here in Texas, we call it ‘Trucking CWD’…
Preventive Veterinary Medicine Volume 234, January 2025, 106385
Use of biosecurity practices to prevent chronic wasting disease in Minnesota cervid herds
Vehicles or trailers that entered the farm were used to transport other live cervids, cervid carcasses, or cervid body parts in past 3 years in 64.3 % (95 % CI 46.3–82.3) of larger elk/reindeer herds compared to 13.6 % (95 % CI 4.7–22.4) of smaller deer herds.
Snip…
Identifying the exact pathway of initial CWD transmission to cervid herds is often not possible, in part due to many potential pathways of transmission for the infection, including both direct and indirect contact with infected farmed or wild cervids (Kincheloe et al., 2021). That study identified that transmissions from infected farmed cervids may occur from direct contact with the movement of cervids from one herd to another and from indirect contact with the sharing of equipment, vehicles, clothing, reproductive equipment, and potentially through semen or embryos.
https://www.sciencedirect.com/science/article/abs/pii/S016758772400271X
Texas is a fine example, see; “Chronic Wasting Disease (CWD) is a fatal neurological disease and can devastate deer populations by silently spreading through direct animal contact and contaminated environments. Without close monitoring, illegal movement of captive deer increases the risk of introducing CWD to areas it is not known to exist, potentially leading to widespread outbreaks which will impact more than just the health of Texas deer.”
https://tpwd.texas.gov/newsmedia/releases/?req=20250227b
THURSDAY, AUGUST 14, 2025
Texas Game Wardens Near Conclusion of ‘Ghost Deer’ Case with 24 Suspects, 1,400 Charges Filed Statewide
https://chronic-wasting-disease.blogspot.com/2025/08/texas-game-wardens-near-conclusion-of.html
https://prpsc.proboards.com/thread/178/texas-game-wardens-conclusion-ghost
Arkansas CWD Deer Study Final Report 2025
https://drive.google.com/file/d/1jN5mtvXvz7IYFDQjv4Rasrw60dGe4KMJ/view
This CWD Study Could Change Deer Hunting FOREVER | The Check Station October 8, 2025 NW Arkansas
NW Arkansas CWD 11:25 minutes;
50% of all deer positive for CWD.
35% of Does are Positive for CWD.
68% Bucks are Positive for CWD.
Most Bucks NW Arkansas that where Tested, are Positive for CWD.
https://m.youtube.com/watch?v=kTicUE-xsQU&t=695s&pp=2AG3BZACAQ%3D%3D
Southwest Wisconsin CWD, Deer and Predator Study
key takeaways ;
CWD substantially reduces deer survival rates and suppresses population growth.
Where CWD prevalence is high, deer populations are likely declining.
If CWD continues to spread, it will eventually impact deer populations elsewhere.
https://dnr.wisconsin.gov/topic/research/projects/dpp/StudyResults
***> CWD TSE PrP Environmental Factors <***
Chronic wasting disease (CWD) prion detection in environmental and biological samples from a taxidermy site and nursing facility, and instruments used in surveillance activities
Available online 9 April 2025
Highlights
• CWD prions were identified in a taxidermy and deer nursing facility.
• Contaminated samples included waters, soils, dermestid beetles, domestic flies and a dumpster.
• Surgical instruments used to collect deer samples can get contaminated with CWD prions.
• Some of the infectious particles are readily released from surgical instruments when washed.
• Our results suggest that taxidermy practices actively contribute in the spreading of CWD.
Snip…
In summary, the information provided in this report demonstrate how anthropogenic activities, specifically taxidermy practices, animal processing, and rehabilitation of CWD susceptible species, may facilitate CWD transmission through the environmental dissemination of CWD prions. This study, along with future research efforts characterizing the overall level of infectivity, provides relevant information on managing CWD and to control its rapid geographic expansion. …
https://www.sciencedirect.com/science/article/abs/pii/S0048969725009544
Chronic wasting disease detection in environmental and biological samples from a taxidermy site
Results: The PMCA analysis demonstrated CWD seeding activity in some of the components of this facility, including insects involved in head processing, soils, and a trash dumpster.
Conclusions: Different areas of this property were used for various taxidermy procedures. We were able to detect the presence of prions in
i) soils that were in contact with the heads of dead animals, ii) insects involved in the cleaning of skulls, and iii) an empty dumpster where animal carcasses were previously placed.
This is the first report demonstrating that swabbing is a helpful method to screen for prion infectivity on surfaces potentially contaminated with CWD. These findings are relevant as this swabbing and amplification strategy may be used to evaluate the disease status of other free-ranging and captive settings where there is a concern for CWD transmissions, such as at feeders and water troughs with CWD-exposed properties. This approach could have substantial implications for free-ranging cervid surveillance as well as in epidemiological investigations of CWD.
Prion 2022 Conference abstracts: pushing the boundaries
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
Artificial mineral sites that pre-date endemic chronic wasting disease become prion hotspots
The Ames Research and Educational Center property, centrally located within the CWD zone of southwest Tennessee, contains 49 historical mineral supplementation sites that were decommissioned in 2012. Here, we demonstrate that 32 of the 49 (65%) mineral sites within Ames established prior to the regional CWD outbreak, serve as foci of environmental PrPCWD contamination. Detection of PrPCWD in soils from these artificial mineral sites was dependent on site-specific management efforts. Soil physical properties were very similar across sites and no correlation between PrPCWD detection and soil physical properties was found. The detection of PrPCWD in soils at attractant sites within an endemic CWD zone significantly advances our understanding of environmental PrPCWD accumulation dynamics, providing valuable information for advancing adaptive CWD management approaches.
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf
Shedding of Chronic Wasting Disease Prions in Multiple Excreta Throughout Disease Course in White-tailed Deer
Conclusions: These studies demonstrate: (a) CWD prion excretion occurs throughout infection; (2) PRNP genotype (GG≫GS/NT) influences the excreta shedding; and (3) detection sensitivity in excreta can vary with different RT-QuIC protocols. These results provide a more complete perspective of prion shedding in deer during the course of CWD infection.
Prion 2022 Conference abstracts: pushing the boundaries
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
"Additionally, we have determined that prion seeding activity is retained for at least fifteen years at a contaminated site following attempted remediation."
15 YEARS!
Detection of prions in soils contaminated by multiple routes
Results: We are able to detect prion seeding activity at multiple types of environmental hotspots, including carcass sites, contaminated captive facilities, and scrapes (i.e. urine and saliva). Differences in relative prion concentration vary depending on the nature and source of the contamination. Additionally, we have determined that prion seeding activity is retained for at least fifteen years at a contaminated site following attempted remediation.
Conclusions: Detection of prions in the environment is of the utmost importance for controlling chronic wasting disease spread. Here, we have demonstrated a viable method for detection of prions in complex environmental matrices. However, it is quite likely that this method underestimates the total infectious prion load in a contaminated sample, due to incomplete recovery of infectious prions. Further refinements are necessary for accurate quantification of prions in such samples, and to account for the intrinsic heterogeneities found in the broader environment.
Funded by: Wisconsin Department of Natural Resources
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
***> Infectious agent of sheep scrapie may persist in the environment for at least 16 years
***> Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded.
JOURNAL OF GENERAL VIROLOGY Volume 87, Issue 12
Infectious agent of sheep scrapie may persist in the environment for at least 16 years Free
https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.82011-0
Rapid recontamination of a farm building occurs after attempted prion removal
First published: 19 January 2019 https://doi.org/10.1136/vr.105054
The data illustrates the difficulty in decontaminating farm buildings from scrapie, and demonstrates the likely contribution of farm dust to the recontamination of these environments to levels that are capable of causing disease. snip...
This study clearly demonstrates the difficulty in removing scrapie infectivity from the farm environment. Practical and effective prion decontamination methods are still urgently required for decontamination of scrapie infectivity from farms that have had cases of scrapie and this is particularly relevant for scrapie positive goatherds, which currently have limited genetic resistance to scrapie within commercial breeds.24 This is very likely to have parallels with control efforts for CWD in cervids.
https://bvajournals.onlinelibrary.wiley.com/doi/abs/10.1136/vr.105054
***>This is very likely to have parallels with control efforts for CWD in cervids.
https://pubmed.ncbi.nlm.nih.gov/30602491/
I remember what “deep throat” told me about Scrapie back around 2001, during early days of my BSE investigation, after my Mom died from hvCJD, I never forgot, and it seems it’s come to pass;
***> Confidential!!!!
***> As early as 1992-3 there had been long studies conducted on small pastures containing scrapie infected sheep at the sheep research station associated with the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are documented...I don't know. But personal recounts both heard and recorded in a daily journal indicate that leaving the pastures free and replacing the topsoil completely at least 2 feet of thickness each year for SEVEN years....and then when very clean (proven scrapie free) sheep were placed on these small pastures.... the new sheep also broke out with scrapie and passed it to offspring. I am not sure that TSE contaminated ground could ever be free of the agent!! A very frightening revelation!!!
---end personal email---end...tss
and so it seems…tss
CWD cash cow, indemnity?
‘cash cow’?
they call it indemnity, tax payers paying for captive CWD?
2025 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
APHIS works with State agencies to encourage cervid owners to certify their herds by meeting the requirements in the CWD Herd Certification Program (HCP) Standards. APHIS’ voluntary national CWD HCP helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds. Currently, 28 States participate in the national CWD HCP.
In 2023, eight percent of the farmed cervids in the HCP were tested for CWD at APHIS and State laboratories.
Of the 303,242 farmed cervids tested in 2023, APHIS confirmed 22 new CWD positive farmed cervid herds.
APHIS provided Federal indemnity to depopulate one of the newly identified positive herds and approved an indemnity payment for a second positive herd which will be provided in 2024 once depopulation occurs. The remaining infected herds are under State quarantines.
APHIS determines the use of Federal indemnity payments within the CWD program on a case-by-case basis. In 2023, APHIS made approximately $12.3 million available for cooperative agreements with States and Tribal governments to further develop and implement CWD surveillance, testing, management, and response activities. This includes the further development and evaluation of techniques and strategies to prevent or control CWD in farmed and wild cervid populations. APHIS funded cooperative agreement with 22 States, 15 universities, and 11 Tribes and Tribal Organizations for CWD projects…
https://www.usda.gov/sites/default/files/documents/22-APHIS-2025-ExNotes.pdf
2024 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
APHIS works with State agencies to encourage cervid owners to certify their herds by meeting the requirements in the CWD Herd Certification Program (HCP) Standards. APHIS’ voluntary national CWD HCP helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds.
Currently, 28 States participate in the national CWD HCP.
In 2022, 7 percent of the 285,589 farmed cervids in the HCP participating states were tested for CWD at State and APHIS laboratories.
APHIS confirmed 23 new CWD positive farmed cervid herds.
APHIS provided Federal indemnity to depopulate nine of the newly identified positive herds in 2022. The remaining infected herds are under State quarantines. APHIS determines the use of Federal indemnity payments within the CWD program on a case-by-case basis. In 2022, APHIS made approximately $9.4 million available for cooperative agreements with States and Tribal governments to further develop and implement CWD surveillance, testing, management, and response activities. This includes the further development and evaluation of techniques and strategies to prevent or control CWD in farmed and wild cervid populations. APHIS funded 27 States and 5 Tribes, 1 Tribal Organization, and 1 State university. The State university agreement was to conduct wild cervid surveillance on Tribal lands…
https://www.usda.gov/sites/default/files/documents/23-2024-APHIS.pdf
2023 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
APHIS coordinates with State agencies to encourage cervid owners to certify their herds and comply with the CWD Herd Certification Program (HCP) Standards…
APHIS’ voluntary national CWD HCP helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds.
Currently, 28 States participate in the national CWD HCP. In FY 2021, more than 20,502 farmed cervids were tested for CWD at State and APHIS laboratories.
As a result, APHIS identified 35 new CWD positive farmed cervid herds.
APHIS provided Federal indemnity to depopulate nine of the newly identified deer herds in FY 2021. The remaining infected herds are under State quarantines. APHIS determines the use of Federal indemnity payments within the CWD program on a case-by-case basis. In 2021, APHIS made $5.6 million available in cooperative agreement funding to further develop and implement CWD surveillance, testing, management, and response activities, including the further development and evaluation of techniques and strategies to prevent or control CWD in farmed and wild cervid populations. APHIS funded awards to 39 entities: 20 to State Departments of Wildlife, 11 to State Departments of Agriculture, and 8 to Tribal Organizations.
https://www.usda.gov/sites/default/files/documents/23-2023-APHIS.pdf
2022 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
APHIS coordinates with State agencies to encourage cervid owners to certify their herds and comply with the CWD Herd Certification Program Standards…
APHIS’ voluntary national CWD Herd Certification Plan (HCP) helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds.
Currently, 28 States participate in the national CWD HCP. In FY 2020, more than 11,182 farmed cervids were tested for CWD at State and APHIS laboratories.
As a result, APHIS identified 22 new CWD positive farmed cervid herds.
APHIS provided Federal indemnity to depopulate 15 of the 22 newly identified deer herds in FY 2020.
Four additional farmed cervid herds that were identified as CWD positive herds in FY 2019, were indemnified in FY 2020.
The remaining infected herds are under State quarantines.
APHIS determines the use of Federal indemnity payments within the CWD program on a case- by-case basis. In FY 2020, APHIS and the Department of Interior held a virtual summit with representatives from State agriculture and wildlife agencies, Tribal Nations, conservation and hunting groups, and the cervid industry to identify and discuss stakeholder CWD management needs and information gaps that need to be addressed to effectively control CWD. The information from the summit helped APHIS establish priorities for proposals for competitive cooperative agreements dedicated to CWD control. These cooperative agreement opportunities allow for State departments of agriculture, State animal health agencies, State departments of wildlife or natural resources, and Tribal governments to further develop and implement CWD management and response activities in accordance with the following priorities:
• improving CWD management of affected farmed herds and free-ranging endemic populations;
• improving CWD management of affected areas or premises;
• conducting additional research on amplification assays;
• conducting additional research on predictive genetics; and,
• developing and/or delivering educational outreach materials or programs.
To execute projects based upon those priorities, APHIS funded awards to 25 entities:
19 to State Departments of Natural Resources, 5 to State Departments of Agriculture, and 1 to Tribal Nations.
https://www.usda.gov/sites/default/files/documents/22APHIS2022Notes.pdf
2021 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
In FY 2019, 10 mule deer were tested as part of the project and all 10 tested negative.
Currently, 28 States participate in APHIS’ voluntary national CWD Herd Certification Plan (HCP).
In FY 2019 APHIS tested more than 11,000 farmed cervids for CWD.
As a result, APHIS identified 17 new CWD positive farmed cervid herds.
APHIS provided Federal indemnity to depopulate 7 of the 17 newly identified deer herds in FY 2019. The remaining infected herds found in FY 2019 are under State quarantines.
https://www.usda.gov/sites/default/files/documents/20aphis2021notes.pdf
2020 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
APHIS’ voluntary national CWD Herd Certification Plan (HCP) helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds.
Currently, 28 States participate in the national CWD HCP and the program used an immunohistochemistry test method to test 21,584 farmed cervids for CWD.
In FY 2018, APHIS identified 15 new CWD positive farmed cervid herds (14 deer herds and 1 reindeer herd).
The reindeer herd in Illinois was the first confirmed case of CWD in a reindeer in North America.
APHIS provided Federal indemnity to depopulate seven of the 15 newly identified deer herds in FY 2018.
The Agency also provided funding for the test and removal of 161 high risk animals that were in close proximity to reactors.
The remaining herds in FY 2018 are under State quarantines.
The Agency determines the use of Federal indemnities within the CWD program on a case-by-case basis. 20-59
https://www.usda.gov/sites/default/files/documents/20aphis2020notes.pdf
2019 President’s Budget Animal and Plant Health Inspection Service
Cervids
APHIS’ voluntary national CWD Herd Certification Plan (HCP) helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds.
Currently, 28 States participate in the national CWD HCP and the program tested 23,053 farmed cervids for CWD.
In FY 2017, eight new CWD positive farmed cervid herds were identified– one white-tail deer in Iowa, one white-tail deer herd in Minnesota, one white-tail and mule deer herd in Minnesota, one white-tail and sika deer herd in Michigan, three white-tail deer herds in Pennsylvania, and one white-tail deer herd in Texas.
APHIS provided Federal indemnity to depopulate the Iowa herd, the white-tail deer herd in Minnesota, one herd in Pennsylvania and the Texas herd. The State depopulated the Michigan herd. The remaining herds are under State quarantines. One Texas herd used Federal indemnity to remove and test select, high-risk animals to inform the epidemiological investigation and to evaluate the performance of ante-mortem tests.
The Agency determines the use of Federal indemnities within the CWD program on a case-by-case basis. The CWD Program Standards provide guidance on how to meet CWD Herd Certification Program and interstate movement requirements. In July 2016, APHIS convened a working group of State and Federal animal health and wildlife officials and representatives from the farmed cervidae industry to review the CWD Program Standards. APHIS issued a summary of the working group’s discussions and recommended changes to the CWD Program Standards at the 2016 United States Animal Health Association meeting for public comment. APHIS evaluated public comments, and is currently reviewing revisions to the CWD Program. In FY 2017, APHIS published VS Guidance 8000: Requirements for Interstate Transport of Wild Caught Cervids. This guidance document establishes a recommended minimum standard for testing and a uniform process of disease risk assessment to help prevent the spread of cervid diseases such as chronic wasting disease (CWD), bovine tuberculosis (TB), and brucellosis when wild cervids are captured for interstate movement and release.
https://www.usda.gov/sites/default/files/documents/20aphis2019notes.pdf
2018 President’s Budget Animal and Plant Health Inspection Service
Cervids
APHIS’ voluntary national CWD Herd Certification Plan (HCP) helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds considered to be low risk.
Currently, 29 States participate in the national CWD HCP.
In FY 2016, the program tested 14,503 farmed cervids for CWD and identified seven new CWD positive farmed cervid herds – two white-tail deer herds in Texas, three white-tail deer herds in Wisconsin, one elk herd in Colorado and one elk herd in Iowa. The elk herd in Colorado was depopulated without Federal indemnity and the rest of the herds are under State quarantines. One Texas herd used Federal indemnity to remove and test select animals to inform the epidemiological investigation and to evaluate 20-72 the performance of ante-mortem tests.
The use of Federal indemnities within the CWD program is determined on a case-by-case basis. APHIS is also conducting several pilot projects related to new technologies. In FY 2016, the Agency sponsored a pilot project in Ohio to evaluate the use of a new method for ante-mortem testing in whitetail deer known as rectoanal mucosa associated lymphoid tissue or RAMALT testing. A proof-of-concept pilot project was also performed by APHIS’ National Veterinary Services Laboratories (NVSL) to evaluate ante-mortem biopsies of the medial retropharyngeal lymph node biopsy or MRPLN biopsy. APHIS anticipates implementing both types of ante- mortem testing in the future. Beginning early September 2014, APHIS, in cooperation with the National Agricultural Statistics Service, conducted the first national study of the U.S. farmed cervid industry. The study surveyed 3,000 producers from all States that have farmed cervids. The study provides baseline industry statistics, a description of current production practices and challenges, producer-reported disease occurrences, and an overview of health management and biosecurity practices. A report from the study is now available in electronic and printed formats at: http://www.aphis.usda.gov/nahms.
https://www.usda.gov/sites/default/files/documents/20aphisexnotes2018.pdf
2017 Explanatory Notes Animal and Plant Health Inspection Service
Cervids
APHIS’ voluntary national CWD Herd Certification Plan (HCP) helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds considered to be low risk.
Currently, 30 States participate in the national CWD HCP: 29 have Approved Status and 1 has Provisional Approved Status. States that meet the CWD HCP requirements have Approved Status and States that do not meet CWD HCP program requirements but have developed a work plan and time frame with APHIS to complete those requirements have Provisional Approved Status.
In FY 2015, the program tested approximately 20,000 farmed cervids for CWD and identified eight new CWD positive farmed white-tailed deer herds – one in Utah, one in Pennsylvania, two in Ohio, two in Wisconsin, and two in Texas.
APHIS depopulated five of these herds (Pennsylvania, Utah, and one each in Wisconsin, Texas, and Ohio). Six elk herds in Colorado, four elk herds in Nebraska, one white-tailed deer herd in Wisconsin and one white-tailed deer herd in Texas remained in quarantine at the end of FY 2015.
APHIS also provided indemnity for and was the lead agency for the depopulation and disposal of four large CWD infected farmed cervid herds in Pennsylvania, Ohio, Utah, and Texas. In cooperation with the National Agricultural Statistics Service, APHIS conducted the first national study of the U.S. farmed-cervid industry in FY 2015. The study provides baseline industry statistics, a description of production practices and challenges, producer-reported disease occurrences, and an overview of health management and biosecurity practices.
https://www.usda.gov/sites/default/files/documents/20aphis2017notes.pdf
2016 Explanatory Notes Animal and Plant Health Inspection Service
https://www.usda.gov/sites/default/files/documents/20aphis2016notes.pdf
2015 Explanatory Notes Animal and Plant Health Inspection Service
https://www.usda.gov/sites/default/files/documents/20aphis2015notes.pdf
2014 Explanatory Notes Animal and Plant Health Inspection Service
https://www.usda.gov/sites/default/files/documents/18aphis2014notes.pdf
USDA EXPLANATORY NOTES ANIMAL AND PLANT HEALTH INSPECTION SERVICE 2025-2014 CHRONIC WASTING DISEASE CWD TSE CERVID
https://chronic-wasting-disease.blogspot.com/2025/09/usda-explanatory-notes-animal-and-plant.html
FRIDAY, OCTOBER 31, 2025
Captive Cervid and the Economic Burden of Chronic Wasting Disease CWD TSE Prion?
https://chronic-wasting-disease.blogspot.com/2025/10/captive-cervid-and-economic-burden-of.html
https://prpsc.proboards.com/thread/183/captive-cervid-economic-burden-prion
APHIS USDA Captive CWD Herds Update by State December 2025 Update
https://chronic-wasting-disease.blogspot.com/2025/12/aphis-usda-captive-cwd-herds-update-by.html
https://prpsc.proboards.com/thread/187/aphis-captive-herds-update-december
MONDAY, FEBRUARY 23, 2026
***> Chronic Wasting Disease CWD TSE Prion, Economical, Environmental, Zoonotic, Risk Factors 2026 <***
https://transmissiblespongiformencephalopathy.blogspot.com/2026/02/chronic-wasting-disease-cwd-tse-prion.html
ARS Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies 2025
“ARS researchers in Ames, Iowa, showed that white-tailed deer sick with scrapie from sheep can infect other deer under conditions mimicking natural exposure. Furthermore, this work shows that CWD is difficult to differentiate from WTD infected with scrapie. WTD scrapie prions accumulate in the lymphoreticular system in a manner similar to CWD, meaning that environmental contamination may occur through feces, saliva, and other body fluids of scrapie affected WTD as has been shown for CWD. The presence of WTD infected with scrapie could confound mitigation efforts for chronic wasting disease. This information informs regulatory officials, the farmed cervid industry, and officials tasked with protecting animal health such as state Departments of Agriculture, Natural Resources, or Parks and Wildlife with regard to a disease similar to CWD but arising from sheep scrapie that could be present in WTD that have contact with scrapie affected sheep and/or goats.”
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
2025 Annual Report
Objectives
Objective 1: Develop highly sensitive detection tools to determine the distribution of CWD and scrapie prions in natural hosts (sheep, goats, cervids) and their environment.
Objective 2: Investigate the pathobiology of CWD, scrapie prion strains, and atypical TSEs in natural hosts including potential cross species transmission events.
Objective 3: Investigate the genetics of CWD susceptibility and resistance in white-tailed deer.
Objective 4: Evaluate the presence of and determine the appropriate methodology for CWD strain determination.
Approach
Eradication or control of a family of diseases is unlikely or impossible when an understanding of the basic mechanisms and influences on transmission are unknown and for which methods to evaluate disease status are lacking. Scrapie and BSE represent the most thoroughly studied TSEs; however, significant knowledge gaps persist with regard to the atypical variants of these diseases. Further, much of the research emphasis to date on genetics of prion disease has focused on the recipient genotype rather than the source. Since both atypical BSE and atypical scrapie have been suggested to occur spontaneously, eradication of these diseases may not be possible unless we expand our understanding of the disease at both the source and recipient level. A better understanding of the tissue distribution and potential transmission of these atypical isolates is critical to understanding what risk these disease variants may pose to ongoing control and eradication efforts. The European epizootic of BSE is waning and efforts to eradicate scrapie in the U.S. and abroad have progressed but are not complete. In the U.S., chronic wasting disease (CWD) presents the most serious challenge to regulatory efforts. CWD appears to be spreading unchecked in both free-ranging and farmed cervids. Methods for antemortem detection of TSEs in general and CWD in particular are needed to fulfill the goal of eradicating scrapie and controlling CWD. Performing these studies will allow us to address critical knowledge gaps that are relevant to developing measures to restrict further disease expansion beyond current, affected populations. Understanding prion disease persistence in animal populations is challenging due to lack of tools for study and a less than complete understanding of transmission among animals within a flock or herd or in naturally occurring reservoirs. In addition to transmission between hosts of like species, free-ranging cervids may come in contact with numerous other species including cattle, sheep, and other susceptible hosts. Transmission of CWD to other species has been studied but limited with regard to the source genotype used. The four primary objectives are inherently linked. Our focus is on developing tools needed for control and research, and using those tools to advance our understanding the complex disease process with the overall goal of eradication and control of disease in livestock, wildlife of economic importance, and potential wildlife reservoirs.
Progress Report
The goals of the project plan for fiscal year (FY) 2025 consisted of 12 milestones, 11 of which were either fully or substantially met. The only milestone in this plan that was not met was due to insufficient animal availability and space constraints. Previous studies utilizing this space are not complete due to longer than anticipated incubation periods and cannot be initiated until those studies are complete. In work toward addressing
Objective 1, “Develop highly sensitive detection tools to determine the distribution of chronic wasting disease (CWD) and scrapie prions in natural hosts (sheep, goats, cervids) and their environment”, we have worked closely with ARS researchers in Pullman, Washington, Animal and Plant Health Inspection Service (APHIS), and university partners. The tools under development are directly utilized by state diagnostic labs and have been shared with the appropriate end users for evaluation. We have also assessed alternative dyes that have do not induce amyloid formation in the amplification based diagnostic assay known as RT-QuIC. While no increase in sensitivity was observed, differences between strains were found offering an additional means to differentiate strains for some TSEs.
Objective 2, “Investigate the pathobiology of CWD, scrapie prion strains, and atypical TSEs in natural hosts including potential cross species transmission events”, the studies in question have been initiated with the goal of furthering the understanding of these TSEs in agriculturally relevant species including the natural host species and other that may be exposed to these TSEs in an agricultural environment. The studies are ongoing and anticipated to last upwards of 5 year and observation of the animals is ongoing. No anticipated signs of disease or relevant reportable information have been seen nor are they expected until near the onset of clinical signs, but if they are observed they will be reported.
Objective 3, “Investigate the genetics of CWD susceptibility and resistance in white-tailed deer”, consists of two subobjectives:
A) Investigate the susceptibility of white-tailed deer to CWD modeling direct contact exposure with infected deer, and
B) Investigate the susceptibility of white-tailed deer to CWD after direct inoculation.
The first of these has been initiated on schedule while the second has been delayed considerably (greater than 3 years at this point) due to insufficient animal space.Upon completion these two studies will aid in understanding the disease and disease progression.
Objective 4, “Evaluate the presence of and determine the appropriate methodology for CWD strain determination”, is dependent upon obtaining a diverse set of CWD isolates. We are continuing the acquisition of these samples. . Strains are one of the least understood aspects of TSEs as a whole and of importance in understanding the risks of CWD. We have initiated studies that will address the biochemical nature of prion strains and how these strains are maintained in a host which will aid in addressing features and differentiation of strains as additional samples become available.
Accomplishments
1. 01 Determined that white-tailed deer (WTD) infected with scrapie from sheep can transmit the disease to other deer under conditions mimicking natural exposure. It has long been suggested that prion disease in deer (chronic wasting disease (CWD)) was caused by the prion agent from sheep. The prion disease that affects sheep, scrapie, has been recognized for hundreds of years. However, chronic wasting disease, a similar disease found in WTD, has only been recognized since the 1960s. ARS researchers in Ames, Iowa, showed that white-tailed deer sick with scrapie from sheep can infect other deer under conditions mimicking natural exposure. Furthermore, this work shows that CWD is difficult to differentiate from WTD infected with scrapie. WTD scrapie prions accumulate in the lymphoreticular system in a manner similar to CWD, meaning that environmental contamination may occur through feces, saliva, and other body fluids of scrapie affected WTD as has been shown for CWD. The presence of WTD infected with scrapie could confound mitigation efforts for chronic wasting disease. This information informs regulatory officials, the farmed cervid industry, and officials tasked with protecting animal health such as state Departments of Agriculture, Natural Resources, or Parks and Wildlife with regard to a disease similar to CWD but arising from sheep scrapie that could be present in WTD that have contact with scrapie affected sheep and/or goats.
2. 02 Showed that gene-targeted mice are capable of reproducing strain specific effects typically limited to natural host species of chronic wasting disease (CWD). CWD is a highly contagious disease of deer, elk, moose, and reindeer found in North America, South Korea, and Scandinavian countries that is caused by misfolded proteins called prions. CWD prions transmit through direct contact between infected animals, or through contaminated soil, grass, or water. All prion diseases exhibit progressive neurodegeneration and ultimately death. Scientists typically study CWD by injecting prions into susceptible animals' brains in lab experiments. Intracranial prion injections are favored because they typically produce shorter incubation periods and higher disease attack rates compared to natural infection. ARS researchers in Ames, Iowa, along with university collaborators showed that this inoculation method can cause the prion strains to change in a way that does not accurately reflect how the disease spreads naturally. They found that using a combination of peripheral inoculation (injection outside the brain) in natural hosts and using novel gene-targeted mice generated in a manner that provides a more natural expression of the inserted prion gene that gives a more accurate picture of how CWD behaves in the real world. The novel mouse model provides an important strategy to precisely assess the zoonotic potential (likelihood of transmission from animals to humans) of CWD and other animal prion diseases using natural routes of transmission. This will impact the tools used and direction of future studies of CWD and other prion diseases allowing more rapid and comprehensive responses to emerging questions aiding both the researchers at the producers they support…end
https://www.ars.usda.gov/research/project/?accnNo=440677&fy=202
Chronic Wasting Disease CWD vs Scrapie TSE Prion
Volume 30, Number 8—August 2024
Research
Scrapie Versus Chronic Wasting Disease in White-Tailed Deer
Zoe J. Lambert1, Jifeng Bian, Eric D. Cassmann, M. Heather West Greenlee, and Justin J. Greenlee
Author affiliations: Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA (Z.J. Lambert); US Department of Agriculture, Ames, Iowa, USA (Z.J. Lambert, J. Bian, E.D. Cassmann, J.J. Greenlee); Iowa State University, Ames (Z.J. Lambert, M.H. West Greenlee) Suggested citation for this article
Abstract
White-tailed deer are susceptible to scrapie (WTD scrapie) after oronasal inoculation with the classical scrapie agent from sheep. Deer affected by WTD scrapie are difficult to differentiate from deer infected with chronic wasting disease (CWD). To assess the transmissibility of the WTD scrapie agent and tissue phenotypes when further passaged in white-tailed deer, we oronasally inoculated wild-type white-tailed deer with WTD scrapie agent. We found that WTD scrapie and CWD agents were generally similar, although some differences were noted. The greatest differences were seen in bioassays of cervidized mice that exhibited significantly longer survival periods when inoculated with WTD scrapie agent than those inoculated with CWD agent. Our findings establish that white-tailed deer are susceptible to WTD scrapie and that the presence of WTD scrapie agent in the lymphoreticular system suggests the handling of suspected cases should be consistent with current CWD guidelines because environmental shedding may occur.
snip…
The potential for zoonoses of cervid-derived PrPSc is still not well understood (6,18,45–47); however, interspecies transmission can increase host range and zoonotic potential (48–50). Therefore, to protect herds and the food supply, suspected cases of WTD scrapie should be handled the same as cases of CWD.
https://wwwnc.cdc.gov/eid/article/30/8/24-0007_article
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
2025 Annual Report
https://transmissiblespongiformencephalopathy.blogspot.com/2025/12/ars-research-elucidating-pathobiology.html
Oklahoma ANOTHER CWD-INFECTED MULE DEER FOUND IN CIMARRON COUNTY
rod.hall@ag.ok.gov, micah.holmes@odwc.ok.gov
ANOTHER CWD-INFECTED MULE DEER FOUND IN CIMARRON COUNTY February 6, 2026
A hunter-harvested mule deer from Cimarron County in Oklahoma’s Panhandle has tested positive for chronic wasting disease (CWD), and the Oklahoma Department of Wildlife Conservation (ODWC) has activated the CWD Response Plan jointly produced with the Oklahoma Department of Agriculture, Food and Forestry. This latest CWD-positive deer was harvested about 3.5 miles west of Felt, near the location where a CWD-positive deer was confirmed last year.
“The CWD Response Plan dictates that we respond to this finding by establishing a Selective Surveillance Area” said Joey McAllister, Wildlife Programs Supervisor with ODWC.
Since this latest infected animal was taken so close to the previous one, the current SSA in Cimarron County will remain unchanged; no new area will be added.
“We will be working through our response plan, and our ultimate goal is to ensure healthy and well-managed deer with as little impact to either the resource or our constituents as possible,” McAllister said.
CWD is an always-fatal neurological disease that affects the brains of deer, elk, moose, and other members of the cervid family, creating holes resembling those in sponges. CWD transmission from wild animals to people or to livestock has never been documented. Oklahoma's first case of a wild deer infected with CWD was confirmed in June 2023 in Texas County in Oklahoma’s Panhandle.
The Wildlife Department has conducted CWD monitoring on hunter-harvested deer and elk, and road-killed deer, since 1999.
ODWC staff will continue monitoring for evidence of CWD within Oklahoma’s borders and will release additional information, including ways deer and elk hunters can help with detection and mitigation. Additional guidelines or management plans will be distributed and well-advertised if determined necessary to further protect Oklahoma’s deer and elk populations.
For more information on the disease, hunting regulations, and proper disposal of infected animals, go to https://www.wildlifedepartment.com/hunting/resources/deer/cwd. Additional human health information relating to CWD is available at https://www.usgs.gov/centers/nwhc/publications. Image Cimarron County SSA map Feb 2026 This map shows the CWD Selective Surveillance Area in Cimarron County.
https://www.wildlifedepartment.com/sites/default/files/styles/width_768/public/2026-02/cim%20co%20ssa_0.jpg.webp?itok=Qj5PPAp1
https://www.wildlifedepartment.com/outdoor-news/another-cwd-infected-mule-deer-found-cimarron-county
Oklahoma fourth case of a wild deer infected with Chronic Wasting Disease
A fourth case of a wild deer infected with Chronic Wasting Disease has prompted the Oklahoma Department of Wildlife Conservation to expand its existing Selective Surveillance Area (SSA) for CWD in Texas County westward and southward.
New CWD-Positive Wild Deer Confirmed in Oklahoma Oklahoma's fourth case of a wild deer infected with Chronic Wasting Disease (CWD) was confirmed this month in the Oklahoma Panhandle. The white-tailed deer was located in Texas County after a landowner reported the animal behaving abnormally.
CWD is an always-fatal neurological disease that affects deer, elk, moose, and other members of the cervid family, creating holes in the brain resembling those in sponges. As part of the state's CWD Response Strategy, the confirmation has prompted the Oklahoma Department of Wildlife Conservation to expand the existing Selective Surveillance Area (SSA) for chronic wasting disease in Texas County westward and southward. The CWD Response Strategy is a plan jointly produced by the Wildlife Department along with the Oklahoma Department of Agriculture, Food and Forestry.
Hunters who harvest a deer within the SSA boundary must comply with specific regulations for handling and moving deer and other cervid parts outside the area. These boundary changes, along with cervid transport rules within an SSA, can be viewed at wildlifedepartment.com/hunting/resources/deer//cwd/ssa.
The site also includes information about voluntary testing sites in Oklahoma's three active SSAs. Dispersed across SSAs in northwestern Oklahoma, the testing sites are locations where hunters may choose to leave the head of their harvested deer or elk to be tested for CWD.
"The Wildlife Department is implementing its response plan to monitor and slow the potential spread of CWD," said Dallas Barber, wildlife biologist over big game for the Wildlife Department. "Our priority is to continue to ensure the health and management of our deer herd in Oklahoma, and the steps in our CWD Response Strategy will help us do that."
The Wildlife Department has conducted CWD monitoring on hunter-harvested deer and elk and road-killed deer since 1999 following the discovery of the disease in a private, commercial elk herd in 1998.
The first in-state CWD case in free-ranging deer was confirmed in June 2023 in Texas County.
CWD does not affect pronghorn antelope, and natural CWD transmission from wild animals to humans or livestock has never been documented. Additional human health information relating to CWD is available at https://www.usgs.gov/centers/nwhc/science/chronic-wasting-disease#publications. For more information on the disease, hunting regulations, and proper disposal of infected animals, go to https://www.wildlifedepartment.com/hunting/resources/deer/cwd.
https://wildlifedepartment.com/hunting/resources/deer/cwd
https://content.govdelivery.com/accounts/OKDWC/bulletins/3ee61ca?reqfrom=share
“CWD does not affect pronghorn antelope, and natural CWD transmission from wild animals to humans or livestock has never been documented.”
Please See;
Chronic wasting disease prions in cervids and wild pigs in North America Preliminary Outbreak Assessment DEFRA 26 January 2026
CWD has continued to spread among captive and free-ranging cervids in North America since it was first detected in the 1960s. The finding of CWD prions in wild pigs in the USA suggests they could contribute towards transmission of the disease, influencing its epidemiology, geographic distribution and interspecies spread. However, further research is needed to confirm this. CWD has never been reported in Great Britain and the current risk of CWD prions being introduced into Great Britain’s wild pig or cervid population ranges from very low to negligible.
https://assets.publishing.service.gov.uk/media/697a3b013c71d838df6bd413/CWD_Prions_in_Cervids_and_Wild_Pigs_in_North_America.pdf
see more on cwd transmitting to pigs, cattle, sheep, by oral route, below, very disturbing, and why…terrible news…terry
ATTENTION Cimarron, Texas, Woodward, Major, and Woods County Hunters
Two CWD-positive cases were confirmed in recent months in Oklahoma: one in Texas County about 4 miles north of Optima Wildlife Management Area, and another about 15 miles east of Woodward.
ODWC’s response plan in cooperation with the Oklahoma Department of Agriculture, Food and Forestry is to contain CWD within areas where it is detected and to minimize its artificial spread to other areas by establishing selective surveillance areas (SSA).
Previously, ODWC was notified by the Texas Parks & Wildlife Department (TPWD) of a road-killed deer infected with chronic wasting disease (CWD) found 2.5 miles south of the Oklahoma-Texas border near Felt, Okla., in southwestern Cimarron County.
https://www.wildlifedepartment.com/hunting/resources/deer/cwd/ssa
SECOND CWD-POSITIVE WILD DEER CONFIRMED IN OKLAHOMA A second wild white-tailed deer has tested positive for chronic wasting disease (CWD) in Oklahoma.
The deer was located about 15 miles east of Woodward in Woodward County after a landowner reported the deer behaving abnormally.
Oklahoma's first case of a wild deer infected with CWD was confirmed the first week of June in Texas County, prompting the activation of the next stage in the state's CWD Response Strategy jointly produced by the Oklahoma Department of Wildlife Conservation and the Oklahoma Department of Agriculture, Food and Forestry.
“We will be working through our response plan implementing surveillance efforts and steps to monitor and slow the potential spread of this disease. Our ultimate goal is to ensure healthy and well-managed deer with as little impact to either the resource or our constituents as possible,” said Jerry Shaw, Wildlife Programs Supervisor with ODWC.
CWD is an always-fatal neurological disease that affects the brains of deer, elk, moose, and other members of the cervid family, creating holes resembling those in sponges. CWD transmission from wild animals to people or to livestock has never been documented.
The Wildlife Department has conducted CWD monitoring on hunter-harvested deer and elk, and road-killed deer, since 1999.
Department staff will continue monitoring for evidence of CWD within Oklahoma’s borders and will release additional information, including ways deer and elk hunters can help with detection and mitigation, as hunting seasons approach.
Additional guidelines or management plans will be distributed and well-advertised if determined necessary to further protect Oklahoma’s deer and elk populations.
Additional human health information relating to CWD is available at https://www.usgs.gov/centers/nwhc/science/chronic-wasting-disease#publications.
For more information on the disease, hunting regulations, and proper disposal of infected animals, go to
https://www.wildlifedepartment.com/hunting/resources/deer/cwd.
https://www.wildlifedepartment.com/outdoor-news/second-cwd-positive-wild-deer-confirmed-oklahoma
CHRONIC WASTING DISEASE CONFIRMED IN ONE FARMED OKLAHOMA ELK
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: Update: CWD genetic resistance project at NADC
Author item Cassmann, Eric item Greenlee, Justin
Submitted to: North American Deer Farmer Publication
Type: Trade Journal Publication Acceptance Date: 11/5/2023 Publication Date: 11/15/2023
Citation: Cassmann, E.D., Greenlee, J.J. 2023. Update: CWD genetic resistance project at NADC. North American Deer Farmer. P. 83. Interpretive Summary:
Technical Abstract: In March of 2020, we began a study to examine the susceptibility of whitetail deer with rare prion protein genotypes to chronic wasting disease (CWD). In the sequence of amino acids that make up the deer prion protein, there are several locations that are variable. These variations are sometimes called polymorphisms. In the data collected from depopulations, whitetail deer with certain prion gene polymorphisms were not positive for CWD. In 2019, Dr. Nick Haley published a paper that showed H95/S96, HH95, and S96/K226 deer from depopulated herds in the US were not CWD positive. Based on the overall low number of deer with these genotypes () we’re unable to determine if they were resistant to CWD or if there were too few deer with these genotypes to be statistically represented in the positive cases. It’s also possible that they could be partially susceptible with longer incubation times than deer with generic (wild type) prion genotypes.
Samples gathered at depopulation represent a snapshot of the herd. It is possible these rare genotypes were exposed, but had not yet accumulated abnormal prion protein to a level detectable by the detection methods used. The NADC susceptibility study was initiated to help answer these questions. We studied deer with polymorphisms at 3 amino acid locations (codons): 95, 96, and 226. Wild type deer are QQ95GG96QQ226. Whitetail deer with wild type prion genotypes were inoculated with CWD and co-housed with other whitetail deer (contact deer) that had rare prion protein genotypes. The genotypes of contact deer included QH95GS96QQ226, QH95GG96QK226, QQ95GS96QQ226, QQ95SS96QQ226, Q95GS96QK226, and QQ95GG96KK226 (bolded text indicates a prion gene polymorphism).
During the first year, we collected feces, saliva, nasal swabs, skin, blood, and rectal biopsies from the inoculated and contact deer to determine if deer are CWD positive and the period of CWD shedding. After the first year, we started collecting rectal biopsies annually on the contact deer, but all other samples are still collected every three months.
Eight out of ten (8/10) inoculated deer developed clinical signs for CWD and tested positive after necropsy (Figure 1). The average time from inoculation to euthanasia of these eight inoculated deer was 23 months. Two inoculated deer are still on-study; one of these deer has tested positive for CWD on rectal biopsy IHC.
To date, two deer from the contact group have developed CWD clinical signs and tested positive (Figure 2).
The positive deer from the contact group had the GS96QK226 and KK226 genotypes.
We have detected CWD prions in rectal biopsies with IHC in three other contact deer as of October 2023.
Their prion genotypes are GS96, QH95GS96, and GS96QK226.
As the experiment continues, we hope to answer 2 main questions.
(1) Are there any prion protein polymorphisms that make deer resistant to CWD, and
(2) what are the CWD shedding dynamics in deer with detectable CWD.
One potential outcome of the study would be identifying genotypes with very long incubation periods that, while susceptible to CWD, still could be used to manage CWD.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=410188
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Experiments have commenced to adapt the assays to differentiate classical scrapie prions in small ruminants from the prions that replicate in small ruminants after experimental exposure to chronic wasting disease prions from elk. Research has continued with aims to improve the application of current protocols and validate standardized novel protocols in the diagnosis of prion infection. The tonsil can be sampled by biopsy in living animals and a study in white-tailed deer was completed using a two-bite tonsil biopsy technique. The diagnostic sensitivity of immunohistochemistry on this tissue source was significantly reduced in deer with early-stage infection and in those carrying the G96S polymorphism.
https://www.ars.usda.gov/research/project/?accnNo=441236&fy=2025
Volume 30, Number 10—October 2024
Research
Temporal Characterization of Prion Shedding in Secreta of White-Tailed Deer in Longitudinal Study of Chronic Wasting Disease, United States
Our findings suggest that deer expressing alternative PRNP polymorphisms might live longer and, although they shed fewer prions throughout CWD course, might over their extended lifespan increase CWD prions in the environment
https://wwwnc.cdc.gov/eid/article/30/10/24-0159_article
Research Paper
Prion protein gene sequence and chronic wasting disease susceptibility in white-tailed deer (Odocoileus virginianus)
Received 21 Sep 2015, Accepted 23 Oct 2015, Accepted author version posted online: 03 Dec 2015, Published online: 21 Dec 2015
The presence of aa96S has been associated with slowed disease progression, longer life span among captive deer,Citation26,27 and does not appear to affect the rate at which prions are shed from infected individuals.Citation38 Additionally, CWD infected mule deer have been found to excrete pathogenic prions while asymptomatic.Citation39 This contributes to concerns that wild deer with aa96S may be shedding infectious prions into the environment for longer periods of time than deer lacking the mutation, but are not symptomatic or detectable by immunohistochemical procedures.
https://www.tandfonline.com/doi/full/10.1080/19336896.2015.1115179#d1e354
https://pmc.ncbi.nlm.nih.gov/articles/PMC4964855/pdf/kprn-09-06-1115179.pdf
Review on PRNP genetics and susceptibility to chronic wasting disease of Cervidae
Review
Open access
Published: 07 October 2021
Volume 52, article number 128, (2021)
“It seems so far that all deer, irrespective of their PRNPgenotype, are susceptible to CWD, but natural selection of the less susceptible alleles has been identified.”
“CWD positive animals with extended time before they succumb to disease likely represent a source of chronic prion shedding within populations and may contribute to environmental contamination.”
https://link.springer.com/article/10.1186/s13567-021-00993-z
Unrealistic Hopes
CAN SCIENCE BREED CWD OUT OF DEER? NOT LIKELY March 22, 2022 By: Patrick Durkin
Proponents of selective breeding hope CWD could be controlled in the wild by producing and releasing disease-proof deer from captive herds, but Samuel thinks that’s unrealistic.
“You’ll never produce enough genetically manipulated deer to overwhelm breeding in a wild population,” he said. “Maybe you could get 40%, 50% or 60% of the less susceptible genotypes out there, but that wouldn’t control CWD.”
Schuler and Samuel also note that science doesn’t yet know if CWD-resistant genotypes also carry physical or behavioral traits that would cause other problems.
“I’m not a geneticist, but these CWD-resistant genotypes aren’t found frequently in natural populations,” Schuler said. “The most CWD-resistant genotypes occur at very low rates, and there’s probably a reason for that. Those genotypes might carry traits that cause other population-limiting problems not yet documented.”
Snip…
Skeptical Scientists
But Krysten Schuler, a wildlife disease ecologist at New York’s Cornell University, is skeptical CWD can be controlled through selective breeding, inside or outside captive facilities.
“I doubt we’re going to breed our way out of this problem,” Schuler said. “It’s a pie-in-the-sky hope. No one has documented a deer surviving CWD, so no one has a truly CWD-resistant deer. Some deer take longer to get CWD, and they might live longer once they get it, but they still get CWD and it still kills them. So how can anyone say they can selectively breed more of something that doesn’t exist?”
Schuler said the most anyone has done is identify deer with relatively uncommon genotypes that delay CWD infection and prolong the deer’s life. “Those deer just take longer to get CWD, and they live maybe three years with it instead of the traditional one or two years,” she said. “You can separate deer in a captive facility, and maybe breed some of them to be more resistant, but that challenge is more problematic in wild herds.” “We have to be certain we’ve found a solution before we waste time and money trying to implement a plan that’s not going to work.” Schuler and Mike Samuel, professor emeritus at the University of Wisconsin-Madison, also worry that longer-lived CWD-infected deer could actually worsen CWD’s spread.
“Be careful what you wish for,” Samuel said. “CWD still has many unknowns and uncertainties. The longer an infected deer lives, the more contact it will have with other deer, and the more prions it will shed on the landscape. CWD prevalence in that herd would likely go up and you’d get more infections in younger deer. And if that happens, those younger deer would spread it farther and faster when dispersing.”
https://deerassociation.com/deer-resistance-cwd/#:~:text=Proponents%20of%20selective%20breeding%20hope%20CWD%20could%20be,overwhelm%20breeding%20in%20a%20wild%20population%2C%E2%80%9D%20he%20said.
Experimental transmission of ovine atypical scrapie to cattle
This study demonstrates for the first time that a TSE agent with BSE-like properties can be amplified in cattle inoculated with atypical scrapie brain homogenate.
https://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-023-01224-3
Timm Konold, John Spiropoulos, Janet Hills, Hasina Abdul, Saira Cawthraw, Laura Phelan, Amy McKenna, Lauren Read, Sara Canoyra, Alba Marín-Moreno & Juan María Torres
Veterinary Research volume 54, Article number: 98 (2023)
Abstract
Classical bovine spongiform encephalopathy (BSE) in cattle was caused by the recycling and feeding of meat and bone meal contaminated with a transmissible spongiform encephalopathy (TSE) agent but its origin remains unknown. This study aimed to determine whether atypical scrapie could cause disease in cattle and to compare it with other known TSEs in cattle. Two groups of calves (five and two) were intracerebrally inoculated with atypical scrapie brain homogenate from two sheep with atypical scrapie. Controls were five calves intracerebrally inoculated with saline solution and one non-inoculated animal. Cattle were clinically monitored until clinical end-stage or at least 96 months post-inoculation (mpi). After euthanasia, tissues were collected for TSE diagnosis and potential transgenic mouse bioassay. One animal was culled with BSE-like clinical signs at 48 mpi. The other cattle either developed intercurrent diseases leading to cull or remained clinical unremarkable at study endpoint, including control cattle. None of the animals tested positive for TSEs by Western immunoblot and immunohistochemistry. Bioassay of brain samples from the clinical suspect in Ov-Tg338 and Bov-Tg110 mice was also negative. By contrast, protein misfolding cyclic amplification detected prions in the examined brains from atypical scrapie-challenged cattle, which had a classical BSE-like phenotype. This study demonstrates for the first time that a TSE agent with BSE-like properties can be amplified in cattle inoculated with atypical scrapie brain homogenate.
snip...
This is the first study in cattle inoculated with naturally occurring scrapie isolates that found the presence of prions resembling classical BSE in bovine brain although this was limited to detection by the ultrasensitive PMCA. The results from thermostability assay confirmed that the isolates were as thermoresistant as the BSE agent as proven in other studies [36, 48]. Previous PMCA studies with various British atypical scrapie isolates did not find any evidence of amplification [49, 50]. This may be explained by the use of ovine brain as substrate rather than brain from Bov-Tg110 mice, which may facilitate conversion to classical BSE prions.
Two hypotheses for prion strain propagation in cross-species transmission experiments have been proposed: conformational selection favours a particular strain conformation out of a mixture of conformations in a scrapie isolate whilst mutation results in the conformational shift of one conformation into another [51]. Following on from the study in mice [17], it has been subsequently suggested that classical BSE properties that arise in atypical scrapie isolates transmitted to cattle may be due to conformational mutation in a new host [52]. It does not confirm that the atypical scrapie agent is the origin of the classical BSE epidemic and further transmission studies would be required to see whether classical BSE can be generated.
Would PMCA applied to brains from cattle exposed to TSE agents other than classical BSE and atypical scrapie also produce a classical BSE-like molecular phenotype? The PMCA product obtained in the thermostability test using a thermosensitive classical scrapie control showed a profile unlike classical BSE. Atypical BSE has been linked to the origin of classical BSE because of its conversion into classical BSE following serial passages in wild-type mice (L-type BSE [11]) and bovine transgenic mice (H-type BSE [53]). Although we have not tested PMCA products of atypical BSE isolates as part of this study, there is no evidence that PMCA products from atypical BSE convert into classical BSE, at least for H-type BSE using bovine brain as substrate [54]. In fact, we were unable to propagate H-type BSE using the same methodology (S Canoyra, A Marín-Moreno, JM Torres, unpublished observation).
The study results support the decision to maintain the current ban on animal meal in feedstuffs for ruminants, particularly as atypical scrapie occurs world-wide, and eradication is unlikely for a sporadic disease.
In summary, experimental inoculation of cattle with the atypical scrapie agent may produce clinical disease indistinguishable from classical BSE, which cannot be diagnosed by conventional diagnostic tests, but prions can be amplified by ultrasensitive tests in both clinically affected and clinically unremarkable cattle, which reveal classical BSE-like characteristics. Further studies are required to assess whether a BSE-like disease can be confirmed by conventional tests, which may initially include a second passage in cattle.
https://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-023-01224-3
Classical BSE prions emerge from asymptomatic pigs challenged with atypical/Nor98 scrapie
Transmission of atypical scrapie to bovinized mice resulted in the emergence of C-BSE prions.
https://www.nature.com/articles/s41598-021-96818-2
Belén Marín, Alicia Otero, Séverine Lugan, Juan Carlos Espinosa, Alba Marín-Moreno, Enric Vidal, Carlos Hedman, Antonio Romero, Martí Pumarola, Juan J. Badiola, Juan María Torres, Olivier Andréoletti & Rosa Bolea
Scientific Reports volume 11, Article number: 17428 (2021) Cite this article
Abstract
Pigs are susceptible to infection with the classical bovine spongiform encephalopathy (C-BSE) agent following experimental inoculation, and PrPSc accumulation was detected in porcine tissues after the inoculation of certain scrapie and chronic wasting disease isolates. However, a robust transmission barrier has been described in this species and, although they were exposed to C-BSE agent in many European countries, no cases of natural transmissible spongiform encephalopathies (TSE) infections have been reported in pigs. Transmission of atypical scrapie to bovinized mice resulted in the emergence of C-BSE prions. Here, we conducted a study to determine if pigs are susceptible to atypical scrapie. To this end, 12, 8–9-month-old minipigs were intracerebrally inoculated with two atypical scrapie sources. Animals were euthanized between 22- and 72-months post inoculation without clinical signs of TSE. All pigs tested negative for PrPSc accumulation by enzyme immunoassay, immunohistochemistry, western blotting and bioassay in porcine PrP mice. Surprisingly, in vitro protein misfolding cyclic amplification demonstrated the presence of C-BSE prions in different brain areas from seven pigs inoculated with both atypical scrapie isolates. Our results suggest that pigs exposed to atypical scrapie prions could become a reservoir for C-BSE and corroborate that C-BSE prions emerge during interspecies passage of atypical scrapie.
snip...
Discussion The outbreak of C-BSE was followed by the appearance of TSE in species that had never been diagnosed with prion diseases and the emergence in humans of vCJD16,17,18. However, no natural prion disease has been described in pigs, even though they were exposed to C-BSE contaminated feed12. Posterior experimental challenges in pigs and mice expressing porcine PrP have demonstrated that, although they are not completely resistant, pigs present a robust transmission barrier for C-BSE prions4,14,19.
However, the possible transmission of a TSE to swine is a public health concern due to the wide use of pork as a source of human food, and the increasing use of pigs as tissue donors, being reported a case of vCJD in a human patient receiving a swine dura mater graft20. Although pigs are apparently non-susceptible to C-BSE after oral challenge4,5,21, infectivity has been detected in tissues from pigs orally inoculated with classical scrapie or CWD10,11. In addition, these positive orally inoculated pigs are often subclinical, what could represent a public health concern, considering that these animals could reach the slaughterhouse without showing signs suggestive of prion disease.
In the present study, we evaluated the transmissibility of atypical scrapie to pigs. Pigs were euthanized between 22- and 72-months post inoculation (mpi), and their tissues tested for PrPSc accumulation and infectivity. We did not find evidence of transmission of atypical scrapie to any of the animals by EIA (Table 2), western blotting, or mouse bioassay (Table 3). PrPSc accumulation can be detected in BSE-challenged pigs at 34 mpi4, and at 22 mpi when inoculated with SBSE7. Although scrapie or CWD-inoculated pigs do not show clinical signs, PrPSc presence can be found in scrapie-challenged animals at 51 mpi11 and as early as 6 mpi in the case of CWD10.
Our main goal was to test the ability of atypical scrapie/Nor98 strain to propagate in swine, given that mice expressing porcine PrP (PoPrP-Tg001/tgPo mice) showed to be susceptible to atypical scrapie inoculation. One atypical scrapie isolate adapted to this transgenic line, reaching a 100% attack rate and rapid incubation periods in serial passages13, a similar adaptation to that observed with the C-BSE agent19. However, when this atypical scrapie isolate was tested for propagation in tgPo mice again, together with other atypical scrapie isolates, no positive results were obtained, in vitro nor in vivo14. These results, together with the negative transmissions showed in the present study, reinforce the conclusion that porcine species is highly resistant to atypical scrapie. However, we only performed one passage in tgPo mice, and further passages in this line and/or PMCA analysis of tgPo brains to detect any possible prion replication would be of interest.
However, it was demonstrated that C-BSE prions can be present as a minor variant in ovine atypical scrapie isolates and that C-BSE can emerge during the passage of these isolates to bovine PrP mice15. Considering that the aforementioned atypical scrapie isolate also acquired BSE-like properties when transmitted to tgPo mice13, and that C-BSE is the only prion that efficiently propagates in swine PrP4,7,14, we decided to investigate whether C-BSE prions could emerge from atypical scrapie during the ovine-porcine interspecies transmission.
Interestingly, PMCA reactions seeded with brain material from 7 pigs propagated in tgBov substrate showing PrPres with identical biochemical characteristics to those of C-BSE (Fig. 1). Positive C-BSE amplification was detected in the brain of pigs inoculated with either the PS152 or TOA3 atypical scrapie isolates, at minimum incubation periods of 28- and 35-months post inoculation, respectively. From each animal, positive reactions were not obtained from all brain areas tested (Supplementary table 1). Although PrPres amplified from the pigs showed C-BSE biochemical characteristics, further bioassays in tgBov mice are required to know whether these prions replicate the neuropathological features of C-BSE.
Altogether, our results and data obtained from transmission studies of prions to pigs, tgPo mice and in vitro studies using porcine substrate have shown that pig PrP has a very limited ability to sustain prion replication. No significant polymorphisms have been described for pig PRNP22, and it has been suggested that the conformational flexibility of pig PrP sequence is very low, limiting the number of PrPSc conformations able to produce misfolding14. No differences have been found between pig and minipig PrP sequences either23, suggesting that the conclusions obtained here could be extrapolated to domestic, non-experimental pigs. However, using tgBov substrate, we have demonstrated in vitro the presence of C-BSE seeding activity in some pig brain areas, suggesting that C-BSE prions emerged during the transmission of ovine atypical scrapie prions to pigs. Interestingly, C-BSE prions did not emerge from brain material of all the pigs, and, of those from which it did emerge, it was not detected in all brarsain areas tested. No correlation between time after inoculation and BSE emergence was found either. When the emergence of C-BSE from atypical scrapie in PMCA was described, it was associated to low levels of C-BSE prions that were present in the original atypical scrapie isolates15. It is possible that this result is related to the great resistance that pigs present to prion diseases, making the penetrance of the BSE prions that could be present in the original inoculum incomplete. In addition, considering that the amount of C-BSE conformers in the atypical scrapie inocula is probably very reduced and perhaps not homogeneously distributed throughout the isolate, it is also possible that not all the pigs received a sufficient amount of C-BSE conformers capable of being detected by PMCA. Finally, we should consider that PMCA amplification of prions is sometimes a stochastic phenomenon, which could explain why no C-BSE propagation was obtained from some of the pigs. It could be also discussed that C-BSE emergence from the pig brains could be related to persistence of the original atypical scrapie inoculum. However, C-BSE amplification was not obtained from all of the pigs and, in some of them (i.e. P-1217 and P-1231) C-BSE propagation was detected in caudal regions of the brain (cerebellum or occipital cortex) but not in more rostral areas (such as parietal cortex). If C-BSE amplification from pig brain samples were associated to inoculum persistence and not bona fide propagation of C-BSE prions it would be expected that such amplification would be detected mainly in the most rostral areas of the brain. Finally, even though the titer generated was not enough to produce disease in the pigs, these results evidence again the issue that pigs could act as subclinical reservoirs for prion diseases as observed with scrapie and CWD, and that the presence of prions can be detected in pigs short after exposure to prions7,10,11.
In conclusion, our findings suggest that, although pigs present a strong transmission barrier against the propagation of atypical scrapie, they can propagate low levels of C-BSE prions. The prevalence of atypical scrapie and the presence of infectivity in tissues from atypical scrapie infected sheep are underestimated24,25. Given that pigs have demonstrated being susceptible to other prion diseases, and to propagate prions without showing signs of disease, the measures implemented to ban the inclusion of ruminant proteins in livestock feed must not be interrupted.
https://www.nature.com/articles/s41598-021-96818-2
The prevalence of atypical scrapie and the presence of infectivity in tissues from atypical scrapie infected sheep are underestimated24,25.
Given that pigs have demonstrated being susceptible to other prion diseases, and to propagate prions without showing signs of disease, the measures implemented to ban the inclusion of ruminant proteins in livestock feed must not be interrupted.
https://www.hjortevilt.no/bekrefter-atypisk-skrantesjuke-pa-hjort-i-etne/?fbclid=IwAR3MGseZb7apE5WXo34vyLRzaElC1OGPn95J-7Q_WQbD93pe-yuWK40N5YM
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
Title: Transmission of the atypical/nor98 scrapie agent to suffolk sheep with VRQ/ARQ, ARQ/ARQ, and ARQ/ARR genotypes
Author
item Cassmann, Eric
item MAMMADOVA, JAJIBA - Orise Fellow
item BENESTAD, SYLVIE - Norwegian Veterinary Institute
item MOORE, SARA JO - Orise Fellow
item Greenlee, Justin
Submitted to: PLoS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2021
Publication Date: 2/11/2021
Citation: Cassmann, E.D., Mammadova, J., Benestad, S., Moore, S., Greenlee, J.J. 2021. Transmission of the atypical/nor98 scrapie agent to suffolk sheep with VRQ/ARQ, ARQ/ARQ, and ARQ/ARR genotypes. PLoS ONE. 16(2). Article e0246503. https://doi.org/10.1371/journal.pone.0246503.
DOI: https://doi.org/10.1371/journal.pone.0246503
Interpretive Summary: Atypical scrapie is a prion disease that affects sheep. Unlike classical scrapie, atypical scrapie is thought to occur spontaneously, and it is unlikely to transmit between sheep under natural conditions. Another notable distinction between classical and atypical scrapie is the prion protein genotype of afflicted sheep and the locations in the brain where misfolded prions accumulate. Atypical scrapie generally occurs in sheep that are resistant to classical scrapie. Misfolded prions are predominantly found in the cerebellum for atypical scrapie and not in the brainstem as seen with classical scrapie. Atypical scrapie is a relevant disease because of its potential association with other prion diseases. Some research has shown that the atypical scrapie agent can undergo a transformation of disease forms that makes it appear like classical scrapie or classical bovine spongiform encephalopathy (mad cow disease). Therefore, atypical scrapie is thought to be a possible source for these prion diseases. We investigated the transmission of the atypical scrapie agent to sheep with three different prion protein genotypes. A diagnosis of atypical scrapie was made in all three genotypes of sheep. Misfolded prion protein was detected earliest in the cerebellum and the retina. This is the first report describing the early accumulation of misfolded prions in the retina of sheep with atypical scrapie. Understanding where misfolded prions accumulate in cases of atypical scrapie can lead to better detection earlier in the disease. Furthermore, the materials derived from this experiment will aid in investigating origins of other prion diseases.
Technical Abstract: Scrapie is a transmissible spongiform encephalopathy that occurs in sheep. Atypical/Nor98 scrapie occurs in sheep with that tend to be resistant to classical scrapie and it is thought to occur spontaneously. The purpose of this study was to test the transmission of the Atypical/Nor98 scrapie agent in three genotypes of Suffolk sheep and characterize the distribution of misfolded prion protein (PrPSc). Ten sheep were intracranially inoculated with brain homogenate from a sheep with Atypical/Nor98 scrapie. All sheep with the ARQ/ARQ and ARQ/ARR genotypes developed Atypical/Nor98 scrapie confirmed by immunohistochemistry, and one (1/3) sheep with the VRQ/ARQ genotype had detectable PrPSc consistent with Atypical/Nor98 scrapie at the experimental endpoint of 8 years. Sheep with mild early accumulations of PrPSc in the cerebellum had concomitant retinal PrPSc. Accordingly, large amounts of retinal PrPSc were identified in clinically affected sheep and sheep with dense accumulations of PrPSc in the cerebellum.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=379280
Research article
Open Access
Goat K222-PrPC polymorphic variant does not provide resistance to atypical scrapie in transgenic mice
Patricia Aguilar-Calvo1, 6, Juan-Carlos Espinosa1, Olivier Andréoletti2, Lorenzo González3, Leonor Orge4, Ramón Juste5 and Juan-María Torres1Email author Veterinary Research201647:96 DOI: 10.1186/s13567-016-0380-7
© The Author(s) 2016
Received: 11 June 2016
Accepted: 1 September 2016
Published: 22 September 2016
Abstract Host prion (PrPC) genotype is a major determinant for the susceptibility to prion diseases. The Q/K222-PrPC polymorphic variant provides goats and mice with high resistance against classical scrapie and bovine spongiform encephalopathy (BSE); yet its effect against atypical scrapie is unknown. Here, transgenic mice expressing the goat wild-type (wt) or the K222-PrPC variant were intracerebrally inoculated with several natural cases of atypical scrapie from sheep and goat and their susceptibility to the prion disease was determined. Goat wt and K222-PrPC transgenic mice were 100% susceptible to all the atypical scrapie isolates, showing similar survival times and almost identical disease phenotypes. The capacity of the K222-PrPC variant to replicate specifically the atypical scrapie strain as efficiently as the goat wt PrPC, but not the classical scrapie or cattle-BSE as previously reported, further suggests the involvement of concrete areas of the host PrPC in the strain-dependent replication of prions.
snip...
Susceptibility to prions and disease phenotypes are likely modulated by conformational properties of prion strains and the PrPC and PrPSc amino acid sequence [13]. Some host PrPC amino acid sequences may have greater “plasticity” or ability to misfold—as proposed for the unique susceptibility of bank voles to a wide variety of prion diseases [14] and to “in vitro” conversion experiments [15]—while others may show the opposite situation, locking PrPC and preventing its conversion by different prion strains. Nonetheless, the plasticity of the host PrPC would not explain why certain amino acid substitutions inhibit the replication of some prion strains but not others. A clear example is the goat K222 variant which provides high resistance against classical scrapie and bovine spongiform encephalopathy (BSE) from cattle—being protective even in heterozygous mice and goats [5, 6, 9]—but it is as efficient as the goat wt PrPC in replicating sheep and goat-BSE [5] and atypical scrapie when intracerebrally inoculated. The resistance of the K222 variant to classical scrapie was associated to the additional positive charge at codon 222 provided by the lysine amino acid, which could interfere with the PrPC:PrPSc interaction, abolishing or lowering the conversion rates of PrPC [16]. Similarly, the perturbations in the PrPC surface charge distribution and structural rearrangements mainly localized at the β2–α2 loop region (residues 169–179 in goat PrPC numbering) are likely to underlie the resistance of the human E/K219 variant against CJD [17].
More recently, the existence of critical initial PrPC–PrPSc interaction sites during the templating of PrPC by different prions was proposed [18]. The involvement of specific PrPC areas in the strain-dependent replication of prions could account for the variable role of the K222-PrPC variant in the susceptibility to scrapie. While for classical scrapie polymorphic variants along the PrPC have been associated to modulate the susceptibility to the disease, for atypical scrapie only few have been reported—A/V136, F/L141, R/H154 and Q/R171 [4, 19]— that, interestingly, are all located within β1–α1 and β2–α2 loops. This area could be the critical segment for atypical scrapie interaction with the host PrPC and therefore any amino acid exchange outside this segment would not affect the capacity of replication of the atypical scrapie, as observed in our transmission study in goat wt and K222-PrPC mice. In fact this area seems to be accessible in the abnormally folded aggregate of the atypical scrapie agent as suggested by the observation that the C-terminal part of atypical scrapie PrPSc can be specifically trimmed by PK [20]. In conclusion, although more information is still needed to decipher the mechanisms of prion conversion, our study points to the involvement of specific PrPC areas in the strain-dependent replication of prions. Thus, strategies to fight prion diseases based on genotype breeding programs should be prion strain targeted.
http://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-016-0380-7
*** Grant Agreement number: 222887 ***
*** Project acronym: PRIORITY ***
*** Project title: Protecting the food chain from prions: shaping European priorities through basic and applied research Funding ***
Scheme: Large-scale integrating project Period covered: from Oct. 1, 2009 to Sept. 30, 2014
Name of the scientific representative of the project's co-ordinator1, Title and Organisation: Jesús R. Requena, Ph.D., Associate Professor, Department of medicine, University of Santiago de Compostela, Spàin. Tel: 34-881815464 Fax: 34-881815403 E-mail: jesus.requena@usc.es
Project website¡ Error! Marcador no definido. address: www.prionpriority.eu
PRIORITY, PROJECT FINAL REPORT
*** 14) Concluding that atypical scrapie can transmit to Humans and that its strain properties change as it transmits between species ***
snip...
http://cordis.europa.eu/docs/results/222/222887/final1-priority-final-report.pdf
see;
https://nor-98.blogspot.com/2016/09/goat-k222-prpc-polymorphic-variant-does.html
Block D: Prion epidemiology
Studies on atypical scrapie were identified as a key element of this block, given the potential risk associated to this agent. We studied the permeability of Human, bovine and porcine species barriers to atypical scrapie agent transmission. Experiments in transgenic mice expressing bovine, porcine or human PrPC suggest that this TSE agent has the intrinsic ability to propagate across these species barriers including the Human one. Upon species barrier passage the biological properties and phenotype of atypical scrapie seem to be altered. Further experiments are currently ongoing (in the framework of this project but also in other projects) in order to: (i) characterize the properties of the prion that emerged from the propagation of atypical scrapie in tg Hu; (ii) to confirm that the phenomena we observed are also true for atypical scrapie isolates other than the ones we have studied.
In parallel, studies in sheep have concluded that:
*** Atypical scrapie can be transmitted by both oral and intracerebral route in sheep with various PRP genotypes
*** Low but consistent amount of infectivity accumulates in peripheral tissue (mammary gland, lymph nodes, placenta, skeletal muscles, nerves) of sheep incubating atypical scrapie.
*** The combination of data from all our studies leads us to conclude that:
*** Atypical scrapie passage through species barriers can lead to the emergence of various prions including classical BSE (following propagation in porcine PRP transgenic mice).
*** Atypical scrapie can propagate, with a low efficacy, in human PrP expressing mice. This suggests the existence of a zoonotic potential for this TSE agent.
snip...
We advance our main conclusions and recommendations, in particular as they might affect public policy, including a detailed elaboration of the evidence that led to them. Our main recommendations are:
a. The issue of re-introducing ruminant protein into the food-chain The opinion of the members of Priority is that sustaining an absolute feed ban for ruminant protein to ruminants is the essential requirement, especially since the impact of non-classical forms of scrapie in sheep and goats is not fully understood and cannot be fully estimated. Therefore, the consortium strongly recommends prohibiting re-introduction of processed ruminant protein into the food-chain. Arguments in support of this opinion are:
• the large (and still uncharacterized) diversity of prion agents that circulate in animal populations;
• the uncertainties related to prion epidemiology in animal populations;
• the unknown efficacy of industrial processes applied to reduce microbiological risk during processed animal protein (PAP) production on most prion agents; • the intrinsic capacity of prions to cross interspecies transmission barriers; • the lack of sensitive methodology for identifying cross contamination in food.
• the evolution of natural food chains in nature (i.e. who eats whom or what) has generated an efficient barrier preventing, to some extent, novel prion epidemies and that this naturally evolved ecology should be respected.
The consortium is also hesitant to introduce processed ruminant proteins into fish food considering the paucity of data on prion infections in fishes and sea animals including those of mammalian origin, and the risk of establishing an environmental contamination of the oceans that cannot be controlled.
b. Atypical prion agents and surveillance
Atypical prion agents (see below) will probably continue to represent the dominant form of prion diseases in the near future, particularly in Europe.
*** Atypical L-type BSE has clear zoonotic potential, as demonstrated in experimental models.
*** Similarly, there are now some data that seem to indicate that the atypical scrapie agent can cross various species barriers.
*** Moreover, the current EU policy for eradicating scrapie (genetic selection in affected flocks) is ineffective for preventing atypical scrapie.
*** The recent identification of cell-to-cell propagation and the protein-encoded strain properties of human neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, suggest that they bear the potential to be transmissible even if not with the same efficiency as CJD. More epidemiological data from large cohorts are necessary to reach any conclusion on the impact of their transmissibility on public health. Re-evaluations of safety precautions may become necessary depending on the outcome of these studies. In that context it would appear valuable
• to develop knowledge related to the pathogenesis and inter-individual transmission of atypical prion agents in ruminants (both intra- and inter-species)
• to improve the sensitivity of detection assays that are applied in the field towards this type of agent
• to maintain a robust surveillance of both animal and human populations
c. The need for extended research on prions
Intensified searching for a molecular determinants of the species barrier is recommended, since this barrier is a key for many important policy areas - risk assessment, proportional policies, the need for screening of human products and food. In this respect, prion strain structural language also remains an important issue for public health for the foreseeable future. Understanding the structural basis for strains and the basis for adaptation of a strain to a new host will require continued fundamental research. Prions maintain a complex two-way relationship with the host cell and fundamental research is needed on mechanisms for their transmission, replication and cause of nervous system dysfunction and death.
Early detection of prion infection, ideally at preclinical stage, also remains crucial for development of effective treatment strategies in humans affected by the disease.
Position of the Priority consortium
Nearly 30 years ago, the appearance in the UK of Bovine Spongiform Encephalopathy (BSE) quickly brought the previously obscure “prion diseases” to the spotlight. The ensuing health and food crises that spread throughout Europe had devastating consequences. In the UK alone, there were more than 36,000 farms directly affected by BSE and the transmission of BSE prions to humans via the food chain has caused over 200 people in Europe to die from variant Creutzfeldt-Jakob disease (vCJD) (http://www.cjd.ed.ac.uk
Origins of prion epidemies
Classical BSE now appears to be under control, with 18 EU Member States having achieved the World Organisation for Animal Health (Office International Epizooties) „negligible risk‟ status (May 2014; http://www.oie.int/en/animal-health-in-the-world/official-disease-status/bse/list-of-bse-risk-status/), and the remaining MS assessed as „controlled‟ risk. Of note, research, including EU-funded research, has played a key role in this success: while the origin of the infection was never defined, the principle driver of the epidemic was identified as prions in Meat and Bone Meal (MBM). Tests based on prion protein-specific antibodies were developed, allowing detection of infected animals, and a better understanding of disease pathogenesis and the distribution of infectivity in edible tissues; experimental investigation of transmission barriers between different species allowed a rational estimation of risks, etc. All of this led to the implementation of rational and effective policies, such as the MBM ban to protect the animal feed chain, and the Specified Risk Material (SRM) regulations to protect the human food chain.
In spite of this progress, prions are still a threat. Epidemiological re-assessment indicates that the ∼10 year incubation period separating the peaks of the BSE and the vCJD epidemics is probably too short. In addition, results from a large number of human tonsil and appendix analyses in the UK suggest that there may be a high number of asymptomatic individuals who are positive for the disease-associated conformer prion protein PrPSc. While vCJD is the only form of human prion disease that has been consistently demonstrated to have lymphoreticular involvement, there has been no systematic investigation of lymphoid tissue in cases with other prion diseases.
The human prion problem
The clinical cases of vCJD identified to date have all shared a common PrP genotype (M129M), although one pre-clinical case was confirmed as an M129V heterozygote, and it has been mooted that perhaps only the M129M proportion of the population is susceptible. However, in the UK appendix study, PrP accumulation was described in samples representing every codon 129 genotype, raising the possibility that genotype does not confer resistance but instead modulates incubation period. Apart from the two UK studies, the lymphoid tissues of non-CJD patients have not been examined for the presence of PrPSc, so, these cases may not solely represent pre-clinical vCJD, but also other forms of prion disease.
Recent experiments in highly susceptible mouse models indicate the presence of infectivity in blood or blood components at late disease stages in sporadic CJD. The significance of this experimental finding for humans has to be explored in more detail and, at the present time, there is no evidence for the transmission of prions via blood in sporadic CJD. However a likely scenario is that all those with signs of infection or abnormal PrP accumulation in peripheral tissue could have infective blood, posing the risk for transmission via blood products, which has been clearly demonstrated in experimental models, and confirmed in several cases of vCJD in man. Altogether, these data clearly demonstrate the potential risk of a second wave of vCJD, particularly when the number people identified with lymphoid accumulation of PrPSc (16/32,411) gives a prevalence estimate in the UK of 493 per million, much higher than the number of clinical cases seen to date.
The animal prion problem
An increasing number of reports on cases of “atypical” BSE in cattle throughout the EU and beyond may lead to a new epidemic, particularly since we still do not understand all factors determining the species barrier. Ovine scrapie is another concern, because it could mask ovine BSE, presumably transmissible to humans. Scrapie is endemic and not likely to be eradicated soon, although current control measures are effective at greatly reducing disease incidence. Atypical forms, which may be spontaneous, are not affected by these control measures and these forms of disease will persist in the global animal population. The low prevalence of these disease forms makes effective surveillance very challenging. However, there is a clear risk attendant on ignoring these cases without an understanding of their possible zoonotic potential, particularly when most forms of human disease have no established aetiology. In summary, atypical cases of BSE and scrapie presently clearly outnumber classical cases in cattle and sheep in all member states.
We will highlight the state-of-the-art knowledge and point out scientific challenges and the major questions for research. Strategic objectives and priorities in Europe in the future for research that aims to control, eliminate or eradicate the threat posed by prions to our food and health are also indicated.
The Priority project has focused on 4 themes, namely the structure, function, conversion and toxicity of prions; detection of prions; mechanisms of prion transmission and spreading and epidemiology of prion diseases. This paper summarizes the opinions/positions reached within these themes at the end of the project.
http://cordis.europa.eu/docs/results/222/222887/final1-priority-final-report.pdf
see;
https://nor-98.blogspot.com/2016/09/goat-k222-prpc-polymorphic-variant-does.html
***> CWD TSE PrP Environmental Factors <***
Chronic wasting disease (CWD) prion detection in environmental and biological samples from a taxidermy site and nursing facility, and instruments used in surveillance activities
Available online 9 April 2025
Highlights
• CWD prions were identified in a taxidermy and deer nursing facility.
• Contaminated samples included waters, soils, dermestid beetles, domestic flies and a dumpster.
• Surgical instruments used to collect deer samples can get contaminated with CWD prions.
• Some of the infectious particles are readily released from surgical instruments when washed.
• Our results suggest that taxidermy practices actively contribute in the spreading of CWD.
Snip…
In summary, the information provided in this report demonstrate how anthropogenic activities, specifically taxidermy practices, animal processing, and rehabilitation of CWD susceptible species, may facilitate CWD transmission through the environmental dissemination of CWD prions. This study, along with future research efforts characterizing the overall level of infectivity, provides relevant information on managing CWD and to control its rapid geographic expansion. …
https://www.sciencedirect.com/science/article/abs/pii/S0048969725009544
Chronic wasting disease detection in environmental and biological samples from a taxidermy site
Results: The PMCA analysis demonstrated CWD seeding activity in some of the components of this facility, including insects involved in head processing, soils, and a trash dumpster.
Conclusions: Different areas of this property were used for various taxidermy procedures. We were able to detect the presence of prions in
i) soils that were in contact with the heads of dead animals, ii) insects involved in the cleaning of skulls, and iii) an empty dumpster where animal carcasses were previously placed.
This is the first report demonstrating that swabbing is a helpful method to screen for prion infectivity on surfaces potentially contaminated with CWD. These findings are relevant as this swabbing and amplification strategy may be used to evaluate the disease status of other free-ranging and captive settings where there is a concern for CWD transmissions, such as at feeders and water troughs with CWD-exposed properties. This approach could have substantial implications for free-ranging cervid surveillance as well as in epidemiological investigations of CWD.
Prion 2022 Conference abstracts: pushing the boundaries
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
Artificial mineral sites that pre-date endemic chronic wasting disease become prion hotspots
The Ames Research and Educational Center property, centrally located within the CWD zone of southwest Tennessee, contains 49 historical mineral supplementation sites that were decommissioned in 2012. Here, we demonstrate that 32 of the 49 (65%) mineral sites within Ames established prior to the regional CWD outbreak, serve as foci of environmental PrPCWD contamination. Detection of PrPCWD in soils from these artificial mineral sites was dependent on site-specific management efforts. Soil physical properties were very similar across sites and no correlation between PrPCWD detection and soil physical properties was found. The detection of PrPCWD in soils at attractant sites within an endemic CWD zone significantly advances our understanding of environmental PrPCWD accumulation dynamics, providing valuable information for advancing adaptive CWD management approaches.
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf
Shedding of Chronic Wasting Disease Prions in Multiple Excreta Throughout Disease Course in White-tailed Deer
Conclusions: These studies demonstrate: (a) CWD prion excretion occurs throughout infection; (2) PRNP genotype (GG≫GS/NT) influences the excreta shedding; and (3) detection sensitivity in excreta can vary with different RT-QuIC protocols. These results provide a more complete perspective of prion shedding in deer during the course of CWD infection.
Prion 2022 Conference abstracts: pushing the boundaries
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
"Additionally, we have determined that prion seeding activity is retained for at least fifteen years at a contaminated site following attempted remediation."
15 YEARS!
Detection of prions in soils contaminated by multiple routes
Results: We are able to detect prion seeding activity at multiple types of environmental hotspots, including carcass sites, contaminated captive facilities, and scrapes (i.e. urine and saliva). Differences in relative prion concentration vary depending on the nature and source of the contamination. Additionally, we have determined that prion seeding activity is retained for at least fifteen years at a contaminated site following attempted remediation.
Conclusions: Detection of prions in the environment is of the utmost importance for controlling chronic wasting disease spread. Here, we have demonstrated a viable method for detection of prions in complex environmental matrices. However, it is quite likely that this method underestimates the total infectious prion load in a contaminated sample, due to incomplete recovery of infectious prions. Further refinements are necessary for accurate quantification of prions in such samples, and to account for the intrinsic heterogeneities found in the broader environment.
Funded by: Wisconsin Department of Natural Resources
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
***> Infectious agent of sheep scrapie may persist in the environment for at least 16 years
***> Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded.
JOURNAL OF GENERAL VIROLOGY Volume 87, Issue 12
Infectious agent of sheep scrapie may persist in the environment for at least 16 years Free
https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.82011-0
Rapid recontamination of a farm building occurs after attempted prion removal
First published: 19 January 2019 https://doi.org/10.1136/vr.105054
The data illustrates the difficulty in decontaminating farm buildings from scrapie, and demonstrates the likely contribution of farm dust to the recontamination of these environments to levels that are capable of causing disease. snip...
This study clearly demonstrates the difficulty in removing scrapie infectivity from the farm environment. Practical and effective prion decontamination methods are still urgently required for decontamination of scrapie infectivity from farms that have had cases of scrapie and this is particularly relevant for scrapie positive goatherds, which currently have limited genetic resistance to scrapie within commercial breeds.24 This is very likely to have parallels with control efforts for CWD in cervids.
https://bvajournals.onlinelibrary.wiley.com/doi/abs/10.1136/vr.105054
***>This is very likely to have parallels with control efforts for CWD in cervids.
https://pubmed.ncbi.nlm.nih.gov/30602491/
I remember what “deep throat” told me about Scrapie back around 2001, during early days of my BSE investigation, after my Mom died from hvCJD, I never forgot, and it seems it’s come to pass;
***> Confidential!!!!
***> As early as 1992-3 there had been long studies conducted on small pastures containing scrapie infected sheep at the sheep research station associated with the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are documented...I don't know. But personal recounts both heard and recorded in a daily journal indicate that leaving the pastures free and replacing the topsoil completely at least 2 feet of thickness each year for SEVEN years....and then when very clean (proven scrapie free) sheep were placed on these small pastures.... the new sheep also broke out with scrapie and passed it to offspring. I am not sure that TSE contaminated ground could ever be free of the agent!! A very frightening revelation!!!
---end personal email---end...tss
and so it seems…
Chronic Wasting Disease CWD TSE Prion
THE CWD TSE Prion aka mad cow type disease is not your normal pathogen.
The TSE prion disease survives ashing to 600 degrees celsius, that’s around 1112 degrees farenheit.
You cannot cook the TSE prion disease out of meat. In fact new data now shows that exposure to high temperatures used to cook the meat increased the availability of prions for in vitro amplification.
you can take the ash and mix it with saline and inject that ash into a mouse, and the mouse will go down with TSE.
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production as well.
the TSE prion agent also survives Simulated Wastewater Treatment Processes.
IN fact, you should also know that the TSE Prion agent will survive in the environment for years, if not decades.
you can bury it and it will not go away.
The TSE agent is capable of infected your water table i.e. Detection of protease-resistant cervid prion protein in water from a CWD-endemic area.
it’s not your ordinary pathogen you can just cook it out and be done
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
http://www.pnas.org/content/97/7/3418.full
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2493038/
Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals
https://bmcvetres.biomedcentral.com/track/pdf/10.1186/1746-6148-9-134.pdf
THURSDAY, FEBRUARY 28, 2019
BSE infectivity survives burial for five years with only limited spread
https://link.springer.com/content/pdf/10.1007%2Fs00705-019-04154-8.pdf
Chronic wasting disease prions on deer feeders and wildlife visitation to deer feeding areas
First published: 10 February 2025
Snip…
Finally, we swabbed 19 feeders in 2 areas where CWD was newly detected, finding prion contamination on swabs from 4 feeders. We show that deer feeders in free-ranging populations with high CWD prevalence become contaminated with CWD prions quickly, becoming a potential site of exposure of deer to CWD prions. Our results also demonstrate the ability to find evidence of prion contamination on deer feeders, even in areas where CWD is newly detected.
Snip…
We found that supplemental feeding increased the risk of exposure to CWD prions due to contamination of feeders, increased deer visitation, and increased deer-to-deer contact.
The 12-fold increase in deer visitation to feeders compared to mast trees and 2-fold increase compared to food plots demonstrates increased risk for direct disease spread.
https://wildlife.onlinelibrary.wiley.com/doi/10.1002/jwmg.70000
Chronic Wasting Disease in Texas A Real Disease with Proven Impacts
Produced by a coalition of concerned hunters, landowners, & conservationists (last update 1/2025)
storymaps.arcgis.com/stories/b93f528938ac48e9b56dcc79953cbec0
Aug 18, 2021
Oh, Deer
Heading Off a Wildlife Epidemic
CWD poses a significant threat to the future of hunting in Texas. Deer population declines of 45 and 50 percent have been documented in Colorado and Wyoming. A broad infection of Texas deer populations resulting in similar population impacts would inflict severe economic damage to rural communities and could negatively impact land markets. Specifically, those landowners seeking to establish a thriving herd of deer could avoid buying in areas with confirmed CWD infections. As they do with anthrax-susceptible properties, land brokers may find it advisable to inquire about the status of CWD infections on properties that they present for sale. Prospective buyers should also investigate the status of the wildlife on prospective properties. In addition, existing landowners should monitor developments as TPWD crafts management strategies to identify and contain this deadly disease.
Dr. Gilliland (c-gilliland@tamu.edu) is a research economist with the Texas Real Estate Research Center at Texas A&M University.
www.recenter.tamu.edu/articles/tierra-grande/oh-d
Scrapie, Humans, Zoonotic, what if?
=====
Transmission of scrapie prions to primate after an extended silent incubation period
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
https://www.nature.com/articles/srep11573
https://www.ars.usda.gov/research/publications/publication/?seqNo115=361032
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
==============
PRION 2015 CONFERENCE
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5019500/
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-68961933-690X
WS-01: Prion diseases in animals and zoonotic potential
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
http://www.tandfonline.com/doi/abs/10.1080/19336896.2016.1163048?journalCode=kprn20
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=313160
Comparing the Distribution of Ovine Classical Scrapie and Sporadic Creutzfeldt-Jakob Disease in Italy: Spatial and Temporal Associations (2002-2014)
Ru G1 ., Pocchiari M2 ., Bertolini S. 1, Pite L.1 , Puopolo M.2 , Ladogana A.2 , Perrotta M.G.3 , Meloni D 1 . (1) National reference center for the study and research on animal encephalopathies and comparative neuropathologies (CEA). Experimental Zooprophylactic Institute of Piemonte, Liguria and Valle d'Aosta, Torino, Italy.
(2) Department of Cellular Biology and Neuroscience, Istituto Superiore di Sanità, Roma, Italy. (3) Office 3 National center for the fight and emergency against animal diseases. Ministry of Health, Roma, Italy.
Aim: This study aims to investigate potential spatial and temporal associations between Creutzfeldt-Jakob disease (CJD) in humans (2010-2014) and ovine classical scrapie (CS) (2002- 2006) in Italy, serving as a proxy for exposure.
Materials and Methods: National data from prion disease surveillance in humans (sporadic CJD) and small ruminants (CS) in Italy were utilized. A descriptive geographic analysis was conducted for each disease individually. Subsequently, an ecological study was performed to compare the occurrence of both diseases at the district and regional levels. Standardized incidence ratios (SIR), adjusted for confounders, were calculated for CJD and CS by district and region, respectively, representing the outcome and proxy of exposure. Considering a possible long incubation period of CJD, two study periods were analysed: 2010-2014 for CJD and 2002-2006 for CS. Eight alternative linear regression models were developed using SIR in humans as the dependent variable and SIR in sheep as the independent variable. These models varied in the scale of SIR data (continuous vs. categorical), geographical level (district vs. region), and the potential past exposure of sheep in specific areas to a known source of infection (via a contaminated vaccine).
Results: The analysis of data at the district level revealed no significant association. However, when considering aggregated regional data, all four models consistently indicated a statistically significant positive association, suggesting a higher incidence of the disease in humans as the regional incidence of sheep scrapie increased.
Conclusions: While the results are intriguing, it is important to acknowledge the inherent limitations of ecological studies. Nevertheless, these findings provide valuable evidence to formulate a hypothesis regarding the zoonotic potential of classical scrapie. Further investigations are necessary, employing specific designs such as analytical epidemiology studies, to test this hypothesis effectively.
Funded by: Italian Ministry of Health Grant number: Realizzazione del programma epidemiologico finalizzato a dare evidenza del potenziale zoonotico delle TSE animali diverse dalla BSE. Prot. N. 0018730-17/07/2015-DGSAFCOD_UO-P
''Nevertheless, these findings provide valuable evidence to formulate a hypothesis regarding the zoonotic potential of classical scrapie. Further investigations are necessary, employing specific designs such as analytical epidemiology studies, to test this hypothesis effectively.''
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
=====
Transmission of Idiopathic human prion disease CJD MM1 to small ruminant mouse models (Tg338 and Tg501).
Enric Vidal1,2, Samanta Giler1,2, Montse Ordóñez1,2, Hasier Eraña3,4, Jorge M. Charco3,4, Guillermo Cantero1,2, Juan C. Espinosa5 , Juan M. Torres5 , Vincent Béringue6 , Martí Pumarola7 and Joaquín Castilla3,8,9
Aims: About 90% of Creutzfeldt-Jakob disease cases are classified as sporadic (sCJD), that is, occur infrequently, randomly and without a known cause. It is a fatal neurodegenerative disease with an incidence of 1-1.5 cases per million per year. Epidemiological studies have been so far unable to establish a causal relationship between sCJD and prion diseases in animals.
The zoonotic potential of sheep scrapie was demonstrated in 2014 (Cassard et al., Nature Communications) through inoculation of transgenic mice overexpressing the human prion protein with scrapie isolates. The resulting prion disease was indistinguishable from that occurring after sCJD inoculation in the same model and, while these results do not demonstrate that sCJD is caused by scrapie prions, they do show that the transmission barrier between ovine and human prions is not absolute. Our aim is to further assess this zoonotic risk.
Materials and methods: we have prepared inocula from 3 sCJD cases (MM1, MV2 and VV2) and 2 VPSPr cases (MM and MV) to verify if it is possible to recover the scrapie phenotype upon inoculation in Tg338 and Tg501 ovinized mouse models. Additionally, two different inocula gCJD (E200K) and GSS (A117V) have been also included in the bioassays as controls for classical and atypical genetic human prions, respectively.
Results: No evidence of transmission was found on a first passage in Tg338 nor Tg501 ovinized mice, but on second passage, 4/10 Tg338 mice succumbed to CJDMM1 (40% attack rate after 645 dpi) and 1/12Tg501 mice (519dpi, 10 still alive). The remaining 2nd passages are still ongoing. Conclusions: In this poster, the neuropathological features of the resulting strain are discussed.
Funded by: MINECO grant number AGL2017-88535-P and PID2021-1222010B-C22 and by Interreg POCTEFA grant number EFA148/16 (RedPRION)
''but on second passage, 4/10 Tg338 mice succumbed to CJDMM1 (40% attack rate after 645 dpi) and 1/12 Tg501 mice (519dpi, 10 still alive). The remaining 2nd passages are still ongoing. Conclusions: In this poster, the neuropathological features of the resulting strain are discussed.''
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates. One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias"
Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously.
snip...
76/10.12/4.6
http://web.archive.org/web/20010305223125/www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
2026 TSE PrP
chronic wasting disease cwd, TSE, cattle, sheep, pigs, cervid, primates, humans, oh my! update 2026
Transmissible Spongiform Encephalopathy TSE
Prion Prp
Chronic Wasting Disease CWD, TSE, PrP
TSE cattle
Price of TSE Prion Poker goes up substantially, all you cattle ranchers and such, better pay close attention here...terry
"Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material."
Transmission of the chronic wasting disease agent from elk to cattle after oronasal exposure
Justin Greenlee, Jifeng Bian, Zoe Lambert, Alexis Frese, and Eric Cassmann Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, IA, USA
Aims: The purpose of this study was to determine the susceptibility of cattle to chronic wasting disease agent from elk.
Materials and Methods: Initial studies were conducted in bovinized mice using inoculum derived from elk with various genotypes at codon 132 (MM, LM, LL). Based upon attack rates, inoculum (10% w/v brain homogenate) from an LM132 elk was selected for transmission studies in cattle. At approximately 2 weeks of age, one wild type steer (EE211) and one steer with the E211K polymorphism (EK211) were fed 1 mL of brain homogenate in a quart of milk replacer while another 1 mL was instilled intranasally. The cattle were examined daily for clinical signs for the duration of the experiment. One steer is still under observation at 71 months post-inoculation (mpi).
Results: Inoculum derived from MM132 elk resulted in similar attack rates and incubation periods in mice expressing wild type or K211 bovine PRNP, 35% at 531 days post inoculation (dpi) and 27% at 448 dpi, respectively. Inoculum from LM132 elk had a slightly higher attack rates in mice: 45% (693 dpi) in wild type cattle PRNP and 33% (468) in K211 mice. Inoculum from LL132 elk resulted in the highest attack rate in wild type bovinized mice (53% at 625 dpi), but no K211 mice were affected at >700 days. At approximately 70 mpi, the EK211 genotype steer developed clinical signs suggestive of prion disease, depression, low head carriage, hypersalivation, and ataxia, and was necropsied. Enzyme immunoassay (IDEXX) was positive in brainstem (OD=4.00, but non-detect in retropharyngeal lymph nodes and palatine tonsil. Immunoreactivity was largely limited to the brainstem, midbrain, and cervical spinal cord with a pattern that was primarily glia-associated.
Conclusions: Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Prion Conference 2023
Transmission of the chronic wasting disease agent from elk to cattle after oronasal exposure
Conclusions: Cattle with the E211K polymorphism are susceptible to the CWD agent after oronasal exposure of 0.2 g of infectious material.
Strain characterization of chronic wasting disease in bovine-PrP transgenic mice
Conclusions: Altogether, these results exhibit the diversity of CWD strains present in the panel of CWD isolates and the ability of at least some CWD isolates to infect bovine species. Cattle being one of the most important farming species, this ability represents a potential threat to both animal and human health, and consequently deserves further study.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
TSE sheep
ARS Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies 2025
“ARS researchers in Ames, Iowa, showed that white-tailed deer sick with scrapie from sheep can infect other deer under conditions mimicking natural exposure. Furthermore, this work shows that CWD is difficult to differentiate from WTD infected with scrapie. WTD scrapie prions accumulate in the lymphoreticular system in a manner similar to CWD, meaning that environmental contamination may occur through feces, saliva, and other body fluids of scrapie affected WTD as has been shown for CWD. The presence of WTD infected with scrapie could confound mitigation efforts for chronic wasting disease. This information informs regulatory officials, the farmed cervid industry, and officials tasked with protecting animal health such as state Departments of Agriculture, Natural Resources, or Parks and Wildlife with regard to a disease similar to CWD but arising from sheep scrapie that could be present in WTD that have contact with scrapie affected sheep and/or goats.”
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
2025 Annual Report
snip…
Accomplishments
1. 01 Determined that white-tailed deer (WTD) infected with scrapie from sheep can transmit the disease to other deer under conditions mimicking natural exposure. It has long been suggested that prion disease in deer (chronic wasting disease (CWD)) was caused by the prion agent from sheep. The prion disease that affects sheep, scrapie, has been recognized for hundreds of years. However, chronic wasting disease, a similar disease found in WTD, has only been recognized since the 1960s. ARS researchers in Ames, Iowa, showed that white-tailed deer sick with scrapie from sheep can infect other deer under conditions mimicking natural exposure. Furthermore, this work shows that CWD is difficult to differentiate from WTD infected with scrapie. WTD scrapie prions accumulate in the lymphoreticular system in a manner similar to CWD, meaning that environmental contamination may occur through feces, saliva, and other body fluids of scrapie affected WTD as has been shown for CWD. The presence of WTD infected with scrapie could confound mitigation efforts for chronic wasting disease. This information informs regulatory officials, the farmed cervid industry, and officials tasked with protecting animal health such as state Departments of Agriculture, Natural Resources, or Parks and Wildlife with regard to a disease similar to CWD but arising from sheep scrapie that could be present in WTD that have contact with scrapie affected sheep and/or goats.
snip…
https://www.ars.usda.gov/research/project/?accnNo=440677&fy=202
Component 6: Transmissible Spongiform Encephalopathies
Sheep scrapie agent can infect white-tailed deer after oronasal exposure.
The origin of chronic wasting disease (CWD) is not known, but it has many similarities to the sheep prion disease called scrapie. It has long been hypothesized that CWD arose through transmission of sheep scrapie to deer. ARS researchers in Ames, Iowa, conducted research to determine if scrapie derived from sheep could be transmitted to white-tailed deer. The deer inoculated with sheep scrapie developed clinical signs and the abnormal prion protein could be detected in a wide range of tissues. These results indicate that deer may be susceptible to sheep scrapie if exposed to the disease in natural or agricultural settings. In addition, several strong similarities between CWD in white-tailed deer and the experimental cases of scrapie in white-tailed deer suggests that it would be difficult to distinguish scrapie from CWD in deer or identify scrapie if a case occurs. This information should be considered by deer farmers for keeping their herds free from prion diseases.
https://www.ars.usda.gov/ARSUserFiles/np103/AnnualReports/NP103%20FY2023%20Annual%20Report_Final.pdf
Chronic Wasting Disease CWD vs Scrapie TSE Prion
Volume 30, Number 8—August 2024
Research
Scrapie Versus Chronic Wasting Disease in White-Tailed Deer
Zoe J. Lambert1, Jifeng Bian, Eric D. Cassmann, M. Heather West Greenlee, and Justin J. Greenlee
Author affiliations: Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA (Z.J. Lambert); US Department of Agriculture, Ames, Iowa, USA (Z.J. Lambert, J. Bian, E.D. Cassmann, J.J. Greenlee); Iowa State University, Ames (Z.J. Lambert, M.H. West Greenlee) Suggested citation for this article
Abstract
White-tailed deer are susceptible to scrapie (WTD scrapie) after oronasal inoculation with the classical scrapie agent from sheep. Deer affected by WTD scrapie are difficult to differentiate from deer infected with chronic wasting disease (CWD). To assess the transmissibility of the WTD scrapie agent and tissue phenotypes when further passaged in white-tailed deer, we oronasally inoculated wild-type white-tailed deer with WTD scrapie agent. We found that WTD scrapie and CWD agents were generally similar, although some differences were noted. The greatest differences were seen in bioassays of cervidized mice that exhibited significantly longer survival periods when inoculated with WTD scrapie agent than those inoculated with CWD agent. Our findings establish that white-tailed deer are susceptible to WTD scrapie and that the presence of WTD scrapie agent in the lymphoreticular system suggests the handling of suspected cases should be consistent with current CWD guidelines because environmental shedding may occur.
snip…
The potential for zoonoses of cervid-derived PrPSc is still not well understood (6,18,45–47); however, interspecies transmission can increase host range and zoonotic potential (48–50). Therefore, to protect herds and the food supply, suspected cases of WTD scrapie should be handled the same as cases of CWD.
https://wwwnc.cdc.gov/eid/article/30/8/24-0007_article
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
2025 Annual Report
https://transmissiblespongiformencephalopathy.blogspot.com/2025/12/ars-research-elucidating-pathobiology.html
atypical Nor-98 Scrapie USA
SATURDAY, FEBRUARY 28, 2026 atypical Nor-98, CH1641, Scrapie, TSE Prion, Update 2026 atypical Nor-98, CH1641, Scrapie, TSE Prion, Update 2026
atypical Nor-98 Scrapie Update 2025 Scrapie typical and atypical USA
FY 2023, 16,646 from sheep and 8,726 from goats.
* There have been 491 NVSL confirmed positive animals (474 classical cases – 471 sheep and 3 goats) and
19 Nor98- like cases since the beginning of RSSS. Figure 3 depicts RSSS collection sites in FY 2023.
https://www.aphis.usda.gov/sites/default/files/scrapie-annual-report.pdf
In 2023, APHIS collected samples from more than 26,000 sheep and goats for scrapie testing. Out of the total number of animals tested in 2023, no animals tested positive for classical scrapie and
one sheep tested positive for non-classical scrapie (Nor98-like)...
https://www.usda.gov/sites/default/files/documents/22-APHIS-2025-ExNotes.pdf
In 2022, APHIS collected samples from more than 23,000 sheep and goats for scrapie testing. Out of the total number of animals tested in 2022, no animals tested positive for classical scrapie and
one sheep tested positive for non-classical scrapie (Nor98-like).
https://www.usda.gov/sites/default/files/documents/23-2024-APHIS.pdf
In FY 2021, APHIS collected samples from more than 30,000 sheep and goats for scrapie testing. Out of the total number of samples processed and reported in FY 2021,
one sheep tested positive for classical scrapie and one sheep tested positive for non-classical scrapie (Nor98-like).
https://www.usda.gov/sites/default/files/documents/23-2023-APHIS.pdf
In FY 2020, APHIS collected samples from 33,839 sheep and goats for scrapie testing. This number represents sample results reported by October 15, 2020 and is expected to slightly increase as the remaining results are processed and reported. No animals tested positive for classical scrapie.
Two sheep tested positive at slaughter for non-classical scrapie (Nor98-like).
https://www.usda.gov/sites/default/files/documents/22APHIS2022Notes.pdf
In FY 2019, APHIS collected samples from 34,730 sheep and goats for scrapie testing, detecting 7 classical scrapie positive animals. Of these animals, five sheep and one goat were from a source flock in Pennsylvania that was found in August 2018, depopulated in October 2018, and tested for scrapie in November 2018. A second goat, which was from an Indiana herd, was sampled at slaughter in June 2019. The source flock completed a cleanup plan and was placed on a 5-year monitoring plan. The source herd of the positive Indiana goat no longer contained any exposed animals and was also placed on a 5-year monitoring plan. A trace-back investigation narrowed the goat’s birth herd to two possible herds. Animals in both herds tested negative for scrapie and were placed on 5-year monitoring plans. There were no classical scrapie cases detected in slaughter sheep in FY 2019.
Also in FY 2019, two sheep tested positive at slaughter for non-classical scrapie (Nor98-like) and were traced back to Colorado flocks.
https://www.usda.gov/sites/default/files/documents/20aphis2021notes.pdf
In FY 2018, APHIS collected samples from 43,625 sheep and goats for scrapie testing, detecting three positive (0.0068%) cases. These figures are based on sample submissions and testing completed by September 30, 2018. FY 2018 values are expected to change when testing is completed for all animals sampled in FY 2018.
In October 2017, a non-classical scrapie case was detected in a sheep from Virginia sampled at slaughter. As a result, the non- classical scrapie affected flock was placed on a 5-year monitoring plan.
https://www.usda.gov/sites/default/files/documents/20aphis2020notes.pdf
In FY 2016, the program identified one flock infected with classical scrapie and one infected with Nor98-like scrapie through slaughter surveillance, and two flocks infected with classical scrapie through on-farm surveillance.
An additional 10 sheep were confirmed with classical scrapie through testing of sheep depopulated from these infected flocks as part of flock clean-up activities conducted in FY 2016.
The Nor98-like scrapie affected flock will be placed on a 5-year monitoring plan.
https://www.usda.gov/sites/default/files/documents/20aphisexnotes2018.pdf
Atypical Nor-98 Scrapie TSE Prion USA State by State Update January 2021
Atypical Nor-98 Scrapie TSE Prion USA State by State Update January 2021
Nor98 cases Diagnosed in the US. To Date
Nor98 cases Diagnosed in the US.
Flock of Origin State FY
Wyoming 2007
Indiana 2007
Pennsylvania 2008
Oregon 2010
Ohio 2010
Pennsylvania 2010
Untraceable 2010
California 2011
Montana 2016
Utah 2017
Montana 2017
Virginia 2018
Colorado 2019
Colorado 2019
Wyoming 2020
Montana 2020
Pennsylvania 2021
Personal Communication from USDA et al Mon, Jan 4, 2021 11:37 am...terry
TUESDAY, SEPTEMBER 22, 2020
APHIS USDA MORE SCRAPIE ATYPICAL Nor-98 Confirmed USA September 15 2020
17 cases of the Nor98 in the USA to date, location, unknown...tss
17 Nor98-like cases since the beginning of RSSS.
https://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_report.pdf
17 Nor98-like cases since the beginning of RSSS. No animals have tested positive for classical scrapie in FY 2021.
https://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_report.pdf
TUESDAY, SEPTEMBER 22, 2020
APHIS USDA MORE SCRAPIE ATYPICAL Nor-98 Confirmed USA September 15 2020
https://scrapie-usa.blogspot.com/2020/09/aphis-usda-more-scrapie-atypical-nor-98.html
MONDAY, JULY 27, 2020
APHIS USDA Nor98-like scrapie was confirmed in a sheep sampled at slaughter in May 2020
https://nor-98.blogspot.com/2020/07/aphis-usda-nor98-like-scrapie-was.html
MONDAY, JULY 13, 2020
Efficient transmission of classical scrapie agent x124 by intralingual route to genetically susceptible sheep with a low dose inoculum
https://scrapie-usa.blogspot.com/2020/07/efficient-transmission-of-classical.html
*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics of BSE in Canada Singeltary reply ;
https://journals.plos.org/plosone/article/comment?id=10.1371/annotation/4f9be886-69fe-4c7c-922b-85b0ecbe6d53
WEDNESDAY, MAY 29, 2019
***> Incomplete inactivation of atypical scrapie following recommended autoclave decontamination procedures
https://nor-98.blogspot.com/2019/05/incomplete-inactivation-of-atypical.html
THURSDAY, DECEMBER 31, 2020
Autoclave treatment of the classical scrapie agent US No. 13-7 and experimental inoculation to susceptible VRQ/ARQ sheep via the oral route results in decreased transmission efficiency
https://scrapie-usa.blogspot.com/2020/12/autoclave-treatment-of-classical.html
Snip…see full text;
https://nor-98.blogspot.com/2021/01/atypical-nor-98-scrapie-tse-prion-usa.html
SATURDAY, FEBRUARY 28, 2026
atypical Nor-98, CH1641, Scrapie, TSE Prion, Update 2026
https://nor-98.blogspot.com/2026/02/atypical-nor-98-ch1641-scrapie-tse.html
TSE Pigs
WEDNESDAY, JANUARY 28, 2026
***> CWD TSE Prions in cervids and wild pigs in North America Preliminary Outbreak <***
Chronic wasting disease prions in cervids and wild pigs in North America Preliminary Outbreak
https://assets.publishing.service.gov.uk/media/697a3b013c71d838df6bd413/CWD_Prions_in_Cervids_and_Wild_Pigs_in_North_America.pdf
https://transmissiblespongiformencephalopathy.blogspot.com/2026/01/chronic-wasting-disease-prions-in.html
THURSDAY, JANUARY 08, 2026
Confucius Ponders, what about Wild Pigs (Sus scrofa) and CWD TSE Prion, and the Environment, what if?
Confucius Ponders, what about Wild Pigs (Sus scrofa), they can cover some distance rather quickly, what about Wild Pigs (Sus scrofa) digging up the terrain, and as they do it, what if these Wild Pigs (Sus scrofa) were exposed to CWD TSE Prion, and then they go on exposing and saturating the land with CWD TSE Prion, then the soil becomes contaminated with CWD TSE Prion, then what about the plants that grow from that soil for the decades to come, what if???
https://prpsc.proboards.com/thread/190/confucius-ponders-wild-pigs-scrofa
https://chronic-wasting-disease.blogspot.com/2026/01/confucius-ponders-what-about-wild-pigs.html
TSE Cattle
USA BSE Testing and Surveillance?
Bottom line, USA is testing so few cows for BSE (<25k tested annually)
https://www.aphis.usda.gov/livestock-poultry-disease/cattle/bse/bse-surveillance-program
BUT, even at those low testing figures, the USA did just confirm another case of BSE just here recently. Feed ban has failed terribly, and CWD is spreading in the USA, at an alarming rate. Recent transmission studies show oral transmission of CWD of Cervid to cattle. Studies also show links of sporadic CJD to BSE, Scrapie, and CWD. It’s a Whole new game of Prion poker now$$$
Wednesday, May 24, 2023
***> WAHIS, WOAH, OIE, United States of America Bovine spongiform encephalopathy Immediate notification
https://wahis.woah.org/#/in-review/5067
https://woahoie.blogspot.com/2023/05/wahis-woah-oie-united-states-of-america.html
https://prpsc.proboards.com/thread/125/wahis-woah-oie-immediate-notification
SATURDAY, MAY 20, 2023
***> Tennessee State Veterinarian Alerts Cattle Owners to Disease Detection Mad Cow atypical L-Type BSE
https://bse-atypical.blogspot.com/2023/05/tennessee-state-veterinarian-alerts.html
https://prpsc.proboards.com/thread/123/tennessee-veterinarian-alerts-cattle-confirmed
MAY 19, 2023
https://www.aphis.usda.gov/aphis/newsroom/stakeholder-info/sa_by_date/sa-2023/bse
2 weeks before the announcement of this recent mad cow case in the USA, i submitted this to the APHIS et al;
***> APPRX. 2 weeks before the recent mad cow case was confirmed in the USA, in Tennessee, atypical L-Type BSE, I submitted this to the APHIS et al;
Document APHIS-2023-0027-0001 BSE Singeltary Comment Submission May 2, 2023
''said 'burden' cost, will be a heavy burden to bear, if we fail with Bovine Spongiform Encephalopathy BSE TSE Prion disease, that is why this information collection is so critical''...
https://www.regulations.gov/comment/APHIS-2023-0027-0002
https://downloads.regulations.gov/APHIS-2023-0027-0002/attachment_1.pdf
Bovine Spongiform Encephalopathy BSE TSE Prion Origin USA?, what if?
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: Sheep are susceptible to the agent of TME by intracranial inoculation and have evidence of infectivity in lymphoid tissues
Author item CASSMANN, ERIC - Oak Ridge Institute For Science And Education (ORISE) item MOORE, SARA - Oak Ridge Institute For Science And Education (ORISE) item SMITH, JODI - Iowa State University item Greenlee, Justin
Submitted to: Frontiers in Veterinary Science Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/14/2019 Publication Date: 11/29/2019 Citation: Cassmann, E.D., Moore, S.J., Smith, J.D., Greenlee, J.J. 2019.
Sheep are susceptible to the agent of TME by intracranial inoculation and have evidence of infectivity in lymphoid tissues.
Frontiers in Veterinary Science. 6:430. https://doi.org/10.3389/fvets.2019.00430. DOI: https://doi.org/10.3389/fvets.2019.00430
Interpretive Summary: Prion diseases are protein misfolding diseases that are transmissible between animals. The outcome of prion infection is irreversible brain damage and death. Transmission can occur between animals of the same or different species, however, transmission between different species is usually less efficient due to the species barrier, which results from differences in the amino acid sequence of the prion protein between the donor and recipient species. The present work evaluated whether transmissible mink encephalopathy (TME) can infect sheep. Our results demonstrate that sheep are susceptible to the TME agent and that the TME agent has similar properties to the agent of L-type atypical bovine spongiform encephalopathy (L-BSE). This work supports the ideas that L-BSE is a possible source for TME in mink and that the practice of feeding cattle with neurologic disease to mink should be avoided. This information is important to farmers who raise cattle, sheep, or mink.
Technical Abstract: Transmissible mink encephalopathy (TME) is a food borne prion disease. Epidemiological and experimental evidence suggests similarities between the agent of TME and L-BSE. This experiment demonstrates the susceptibility of four different genotypes of sheep to the agent of TME by intracranial inoculation. The four genotypes of sheep used in this experiment had polymorphisms corresponding to codons 136 and 171 of the prion gene: VV136QQ171, AV136QQ171, AA136QQ171, and AA136QR171. All intracranially inoculated sheep without comorbidities (15/15) developed clinical scrapie and had detectable PrPSc by immunohistochemistry, western blot, and enzyme immunoassay (EIA). The mean incubation periods in TME infected sheep correlated with their relative genotypic susceptibility. There was peripheral distribution of PrPSc in the trigeminal ganglion and neuromuscular spindles; however, unlike classical scrapie and C-BSE in sheep, ovine TME did not accumulate in the lymphoid tissue. To rule out the presence of infectious, but proteinase K susceptible PrPSc, the lymph nodes of two sheep genotypes, VV136QQ171 and AA136QQ171, were bioassayed in transgenic ovinized mice. None of the mice (0/32) inoculated by the intraperitoneal route had detectable PrPSc by EIA. Interestingly, mice intracranially inoculated with RPLN tissue from a VV136QQ171 sheep were EIA positive (3/17) indicating that sheep inoculated with TME harbor infectivity in their lymph nodes. Western blot analysis demonstrated similarities in the migration patterns between ovine TME and the bovine TME inoculum. Overall, these results demonstrate that sheep are susceptible to the agent of TME, and that the tissue distribution of PrPSc in TME infected sheep is distinct from classical scrapie.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=363305
https://www.ars.usda.gov/research/publications/publication/?seqNo115=360665
https://www.ars.usda.gov/research/publications/publication/?seqNo115=373668
Previous work has shown that the Stetsonville, WI outbreak of TME could have been precipitated by feeding mink a downer cow with atypical BSE; therefore, it very well may have originated from a cow with L-BSE. The agent of TME appears to remain stable, and it has a high transmission efficiency after a sequence of interspecies transmission events. Although C-BSE is the archetypal foodborne TSE, our findings indicate that L-BSE and bTME have greater transmission efficiencies in bovinized mice. Previous work has demonstrated that L-BSE also is more virulent than C-BSE in mice expressing the human prion protein [46, 55]. Although the documented incidence of L-BSE is low, the propensity of L-BSE and the TME agent to cross species barriers support the continued monitoring for atypical BSE.
https://bmcvetres.biomedcentral.com/articles/10.1186/s12917-020-02611-0
***>This work supports the ideas that L-BSE is a possible source for TME in mink and that the practice of feeding cattle with neurologic disease to mink should be avoided. This information is important to farmers who raise cattle, sheep, or mink.<***
1985
Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.
snip...
The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...
https://web.archive.org/web/20090506002258/http://www.bseinquiry.gov.uk/files/mb/m09/tab05.pdf
https://web.archive.org/web/20090506001031/http://www.bseinquiry.gov.uk/files/mb/m09a/tab01.pdf
https://web.archive.org/web/20090506024922/http://www.bseinquiry.gov.uk/files/yb/1987/06/10004001.pdf
Re-USA BSE Surveillance, BSE Testing, BSE Feed Regulation (21 CFR 589.2000), SRMs, and CWD
“Conclusion: These results demonstrate the oral transmission potential of atypical BSE in cattle. Surprisingly, regardless of which atypical type of BSE was used for P1 oral challenge, Prpsc in the P2 animals acquired biochemical characteristics similar to that of Prps in C-BSE, suggesting atypical BSE as a possible origin of C-BSE in UK.”
Abstract for Prion 2023
Title: Transmission of atypical BSE: a possible origin of Classical BSE in cattle…end…TSS
TSE cervid
PLoS One. 2020 Aug 20;15(8):e0237410. doi: 10.1371/journal.pone.0237410. eCollection 2020.
Very low oral exposure to prions of brain or saliva origin can transmit chronic wasting disease
Nathaniel D Denkers 1 , Clare E Hoover 2 , Kristen A Davenport 3 , Davin M Henderson 1 , Erin E McNulty 1 , Amy V Nalls 1 , Candace K Mathiason 1 , Edward A Hoover 1
PMID: 32817706 PMCID: PMC7446902 DOI: 10.1371/journal.pone.0237410
Abstract
The minimum infectious dose required to induce CWD infection in cervids remains unknown, as does whether peripherally shed prions and/or multiple low dose exposures are important factors in CWD transmission. With the goal of better understand CWD infection in nature, we studied oral exposures of deer to very low doses of CWD prions and also examined whether the frequency of exposure or prion source may influence infection and pathogenesis. We orally inoculated white-tailed deer with either single or multiple divided doses of prions of brain or saliva origin and monitored infection by serial longitudinal tissue biopsies spanning over two years. We report that oral exposure to as little as 300 nanograms (ng) of CWD-positive brain or to saliva containing seeding activity equivalent to 300 ng of CWD-positive brain, were sufficient to transmit CWD disease. This was true whether the inoculum was administered as a single bolus or divided as three weekly 100 ng exposures. However, when the 300 ng total dose was apportioned as 10, 30 ng doses delivered over 12 weeks, no infection occurred. While low-dose exposures to prions of brain or saliva origin prolonged the time from inoculation to first detection of infection, once infection was established, we observed no differences in disease pathogenesis. These studies suggest that the CWD minimum infectious dose approximates 100 to 300 ng CWD-positive brain (or saliva equivalent), and that CWD infection appears to conform more with a threshold than a cumulative dose dynamic.
Snip…
Discussion
As CWD expands across North America and Scandinavia, how this disease is transmitted so efficiently remains unclear, given the low concentrations of prions shed in secretions and excretions [13, 14]. The present studies demonstrated that a single oral exposure to as little as 300nmg of CWD-positive brain or equivalent saliva can initiate infection in 100% of exposed white-tailed deer. However, distributing this dose as 10, 30 ng exposures failed to induce infection. Overall, these results suggest that the minimum oral infectious exposure approaches 100 to 300 ng of CWD-positive brain equivalent. These dynamics also invite speculation as to whether potential infection co-factors, such as particle binding [46, 47] or compromises in mucosal integrity may influence infection susceptibility, as suggested from two studies in rodent models [48, 49].
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237410
PRION 2023 CONTINUED;
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Prion 2023 Experimental Oronasal Inoculation of the Chronic Wasting Disease Agent into White Tailed Deer
Author list: Sarah Zurbuchena,b , S. Jo Moorea,b , Jifeng Biana , Eric D. Cassmanna , and Justin J. Greenleea . a. Virus and Prion Research Unit, National Animal Disease Center, ARS, United States Department of Agriculture, Ames, IA, US b. Oak Ridge Institute for Science and Education (ORISE), U.S. Department of Energy, Oak Ridge, TN, United States
Aims: The purpose of this experiment was to determine whether white-tailed deer (WTD) are susceptible to inoculation of chronic wasting disease (CWD) via oronasal exposure.
Materials and methods: Six male, neutered WTD were oronasally inoculated with brainstem material (10% w/v) from a CWD-positive wild-type WTD. The genotypes of five inoculated deer were Q95/G96 (wild-type). One inoculated deer was homozygous S at codon 96 (96SS). Cervidized (Tg12; M132 elk PrP) mice were inoculated with 1% w/v brainstem homogenate from either a 96GG WTD (n=10) or the 96SS WTD (n=10).
Results: All deer developed characteristic clinical signs of CWD including weight loss, regurgitation, and ataxia. The 96SS individual had a prolonged disease course and incubation period compared to the other deer. Western blots of the brainstem on all deer yielded similar molecular profiles. All deer had widespread lymphoid distribution of PrPCWD and neuropathologic lesions associated with transmissible spongiform encephalopathies. Both groups of mice had a 100% attack rate and developed clinical signs, including loss of body condition, ataxia, and loss of righting reflex. Mice inoculated with material from the 96SS deer had a significantly shorter incubation period than mice inoculated with material from 96GG deer (Welch two sample T-test, P<0.05). Serial dilutions of each inocula suggests that differences in incubation period were not due to a greater concentration of PrPCWD in the 96SS inoculum. Molecular profiles from western blot of brain homogenates from mice appeared similar regardless of inoculum and appear similar to those of deer used for inoculum.
Conclusions: This study characterizes the lesions and clinical course of CWD in WTD inoculated in a similar manner to natural conditions. It supports previous findings that 96SS deer have a prolonged disease course. Further, it describes a first pass of inoculum from a 96SS deer in cervidized mice which shortened the incubation period.
Funded by: This research was funded in its entirety by congressionally appropriated funds to the United States Department of Agriculture, Agricultural Research Service. The funders of the work did not influence study design, data collection, analysis, decision to publish, or preparation of the manuscript.
Acknowledgement: We thank Ami Frank and Kevin Hassall for their technical contributions to this project.
=====end
PRION 2023 CONTINUED;
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Camel Prion Disease PrP
Thursday, February 19, 2026
Identification of Camel Prion Disease in Tunisia: evidence of an emerging prion disease in North Africa
https://camelusprp.blogspot.com/2026/02/identification-of-camel-prion-disease.html
Raccoon TSE PrP
The chronic wasting disease agent from white-tailed deer is highly infectious to humanized mice after passage through raccoons
https://www.ars.usda.gov/research/publications/publication/?seqNo115=400777
CWD TSE primates and humans
***> Human CWD TSE PrP, what if?
the problem is, to date, there is NO diagnostic criteria set in stone that would confirm a case of human Cwd, like there was with nvCJD (my Mom died from confirmed hvCJD a rare strain of the infamous sporadic CJDs with new strains mounting, sporadic CJD simply means ‘unknown’, IT DOES NOT MEAN 85%+ SPORADIC CJD IS ALL SPONTANEOUS, that’s all iatrogenic CJD is sporadic CJD, until the iatrogenic event is detected, confirmed, traced back, confirmed, put I to the academic domain, and finally, if your lucky, finally published to the media, and finally the public domain.) sorry, I got off course…but let me perfectly clear here, all science to date shows, Human CWD will not look like New Variant Creutzfeldt Jakob disease nvCJD. CWD to humans will look like some variant of sporadic Creutzfeldt Jakob Disease. And here me out very clearly, and this is from the to TSE Prion Gods themselves, old correspondence from way back during my investigations early BSE nvCJD days…2002
“Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.”
*** now, let’s see what the authors said about this casual link, personal communications years ago, and then the latest on the zoonotic potential from CWD to humans from the TOKYO PRION 2016 CONFERENCE.
see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ????
“Our conclusion stating that we found no strong evidence of CWD transmission to humans”
Subject: CWD aka MAD DEER/ELK TO HUMANS ???
Date: September 30, 2002 at 7:06 am PST
From: "Belay, Ermias"
To: Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"
Sent: Monday, September 30, 2002 9:22 AM
Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Dear Sir/Madam, In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD.. That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091).
Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.
Ermias Belay, M.D. Centers for Disease Control and Prevention
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM .......snip........end..............TSS
-----Original Message-----
From:
Sent: Sunday, September 29, 2002 10:15 AM
To: rr26k@nih.gov; rrace@niaid.nih.gov; ebb8@CDC.GOV
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM .......snip........end..............TSS
“regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD”
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ …
######## Bovine Spongiform Encephalopathy <BSE-L@UNI-KARLSRUHE.DE> #########
Dear Terry,
An excellent piece of review as this literature is desparately difficult to get back from Government sites. What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported.
Well, if you dont look adequately like they are in USA currenly then you wont find any!
Steve Dealler
########### http://mailhost.rz.uni-karlsruhe.de/warc/bse-l.html ############
Subject: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
From: "Terry S. Singeltary Sr." <flounder@WT.NET>
Reply To: Bovine Spongiform Encephalopathy <BSE-L@UNI-KARLSRUHE.DE>
Date: Thu, 17 Oct 2002 17:04:51 -0700
snip...
''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994
snip...see full report ;
http://web.archive.org/web/20090506050043/http://www.bseinquiry.gov.uk/files/yb/1994/08/00004001.pdf
http://web.archive.org/web/20090506050007/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
http://web.archive.org/web/20090506050244/http://www.bseinquiry.gov.uk/files/yb/1994/07/00001001.pdf
Stephen Dealler is a consultant medical microbiologist deal@airtime.co.uk BSE Inquiry Steve Dealler Management In Confidence BSE: Private Submission of Bovine Brain Dealler
snip...end
########### http://mailhost.rz.uni-karlsruhe.de/warc/bse-l.html ############
***> ''The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).''
GAME FARM INDUSTRY WANTS TO COVER UP FINDINGS OF INCREASE RISK TO CJD FROM CERVID
BSE INQUIRY
CJD9/10022
October 1994
Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane
BerksWell Coventry CV7 7BZ
Dear Mr Elmhirst,
CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT
Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.
The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended.. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.
The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.
The statistical results regarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.
I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.
http://web.archive.org/web/20030511010117/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
MONDAY, FEBRUARY 25, 2019
***> MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019
https://bseinquiry.blogspot.com/2019/02/mad-dogs-and-englishmen-bse-scrapie-cwd.html
*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***
http://www.tandfonline.com/doi/full/10.4161/pri.28124?src=recsys
http://www.tandfonline.com/doi/pdf/10.4161/pri.28124?needAccess=true
https://wwwnc.cdc.gov/eid/article/20/1/13-0858_article
So, this is what we leave our children and grandchildren?
CDC CWD TSE Prion Update 2025
KEY POINTS
Chronic wasting disease affects deer, elk and similar animals in the United States and a few other countries.
The disease hasn't been shown to infect people.
However, it might be a risk to people if they have contact with or eat meat from animals infected with CWD.
https://www.cdc.gov/chronic-wasting/about/index.html
Prions in Muscles of Cervids with Chronic Wasting Disease, Norway
Volume 31, Number 2—February 2025
Research
Prions in Muscles of Cervids with Chronic Wasting Disease, Norway
Snip…
In summary, the results of our study indicate that prions are widely distributed in peripheral and edible tissues of cervids in Norway, including muscles. This finding highlights the risk of human exposure to small amounts of prions through handling and consuming infected cervids.
Appendix
https://wwwnc.cdc.gov/eid/article/31/2/24-0903-app1.pdf
https://wwwnc.cdc.gov/eid/article/31/2/24-0903_article
Volume 31, Number 2—February 2025
Dispatch
Detection of Chronic Wasting Disease Prions in Raw, Processed, and Cooked Elk Meat, Texas, USA
Snip…
Of note, our data show that exposure to high temperatures used to cook the meat increased the availability of prions for in vitro amplification. Considering the potential implications in food safety and public health, we believe that the findings described in this study warrant further research. Our results suggest that although the elk meat used in this study resisted different manipulations involved in subsequent consumption by humans, their zoonotic potential was limited. Nevertheless, even though no cases of CWD transmission to human have been reported, the potential for human infection is still unclear and continued monitoring for zoonotic potential is warranted.
https://wwwnc.cdc.gov/eid/article/31/2/24-0906_article
Detection of chronic wasting disease prions in processed meats
Results: Our results show positive prion detection in all the samples analyzed using deer and elk substrates. Surprisingly, cooked meats displayed increased seeding activities. This data suggests that CWD-prions are available to people even after meats are processed and cooked.
Conclusions: These results suggest CWD prions are accessible to humans through meats, even after processing and cooking. Considering the fact that these samples were collected from already processed specimens, the availability of CWD prions to humans is probably underestimated.
"Our results show positive prion detection in all the samples analyzed using deer and elk substrates. Surprisingly, cooked meats displayed increased seeding activities."
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
DETECTION OF CHRONIC WASTING DISEASE PRIONS IN PROCESSED MEATS.
In this study, we analyzed different processed meats derived from a pre-clinical, CWD-positive free-ranging elk. Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats. CWD-prion presence in these products were assessed by PMCA using deer and elk substrates. Our results show positive prion detection in all products. To confirm the resilience of CWD-prions to traditional cooking methods, we grilled and boiled the meat products and evaluated them for any remnant PMCA seeding activity. Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking. Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
Products tested included filets, sausages, boneless steaks, burgers, ham steaks, seasoned chili meats, and spiced meats.
CWD-prion presence in these products were assessed by PMCA using deer and elk substrates.
Our results show positive prion detection in all products.
Results confirmed the presence of CWD-prions in these meat products suggesting that infectious particles may still be available to people even after cooking.
Our results strongly suggest ongoing human exposure to CWD-prions and raise significant concerns of zoonotic transmission through ingestion of CWD contaminated meat products.
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true
Transmission of prion infectivity from CWD-infected macaque tissues to rodent models demonstrates the zoonotic potential of chronic wasting disease.
Further passage to cervidized mice revealed transmission with a 100% attack rate.
Our findings demonstrate that macaques, considered the best model for the zoonotic potential of prions, were infected upon CWD challenge, including the oral one.
The disease manifested as atypical in macaques and initial transgenic mouse transmissions, but with infectivity present at all times, as unveiled in the bank vole model with an unusual tissue tropism.
Epidemiologic surveillance of prion disease among cervid hunters and people likely to have consumed venison contaminated with chronic wasting disease
=====
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true
Fortuitous generation of a zoonotic cervid prion strain
Aims: Whether CWD prions can infect humans remains unclear despite the very substantial scale and long history of human exposure of CWD in many states or provinces of USA and Canada. Multiple in vitro conversion experiments and in vivo animal studies indicate that the CWD-to-human transmission barrier is not unbreakable. A major long-term public health concern on CWD zoonosis is the emergence of highly zoonotic CWD strains. We aim to address the question of whether highly zoonotic CWD strains are possible.
Materials and Methods: We inoculated several sCJD brain samples into cervidized transgenic mice (Tg12), which were intended as negative controls for bioassays of brain tissues from sCJD cases who had potentially been exposed to CWD. Some of the Tg12mice became infected and their brain tissues were further examined by Western blot as well as serial passages in humanized or cervidized mice.
Results: Passage of sCJDMM1 in transgenic mice expressing elk PrP (Tg12) resulted in a “cervidized” CJD strain that we termed CJDElkPrP. We observed 100% transmission of the original CJDElkPrP in transgenic mice expressing human PrP. We passaged CJDElkPrP two more times in the Tg12mice. We found that such second and third passage CJDElkPrP prions retained 100% transmission rate in the humanized mice, despite that the natural elk CWD isolates and CJDElkPrP share the same elk PrP sequence. In contrast, we and others found zero or poor transmission of natural elk CWD isolates in humanized mice.
Conclusions: Our data indicate that highly zoonotic cervid prion strains are not only possible but also can retain zoonotic potential after serial passages in cervids, suggesting a very significant and serious long-term risk of CWD zoonosis given that the broad and continuing spread of CWD prions will provide fertile grounds for the emergence of zoonotic CWD strains over time.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
Transmission of cervid prions to humanized mice demonstrates the zoonotic potential of CWD
Samia Hannaoui1 · Irina Zemlyankina1 · Sheng Chun Chang1 · Maria Immaculata Arifn1 · Vincent Béringue2 · Debbie McKenzie3 · Hermann M. Schatzl1 · Sabine Gilch1
Received: 24 May 2022 / Revised: 5 August 2022 / Accepted: 7 August 2022
© The Author(s) 2022
Abstract
Prions cause infectious and fatal neurodegenerative diseases in mammals. Chronic wasting disease (CWD), a prion disease of cervids, spreads efficiently among wild and farmed animals. Potential transmission to humans of CWD is a growing concern due to its increasing prevalence. Here, we provide evidence for a zoonotic potential of CWD prions, and its probable signature using mice expressing human prion protein (PrP) as an infection model. Inoculation of these mice with deer CWD isolates resulted in atypical clinical manifestation with prion seeding activity and efficient transmissible infectivity in the brain and, remarkably, in feces, but without classical neuropathological or Western blot appearances of prion diseases. Intriguingly, the protease-resistant PrP in the brain resembled that found in a familial human prion disease and was transmissible upon second passage. Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
Keywords Chronic wasting disease · CWD · Zoonotic potential · Prion strains · Zoonotic prions
HIGHLIGHTS OF THIS STUDY
================================
Our results suggest that CWD might infect humans, although the transmission barrier is likely higher compared to zoonotic transmission of cattle prions. Notably, our data suggest a different clinical presentation, prion signature, and tissue tropism, which causes challenges for detection by current diagnostic assays. Furthermore, the presence of infectious prions in feces is concerning because if this occurs in humans, it is a source for human-to-human transmission. These findings have strong implications for public health and CWD management.
In this study, we evaluated the zoonotic potential of CWD using a transgenic mouse model overexpressing human M129-PrPC (tg650 [12]). We inoculated tg650mice intracerebrally with two deer CWD isolates, Wisc-1 and 116AG [22, 23, 27, 29]. We demonstrate that this transgenic line was susceptible to infection with CWD prions and displayed a distinct leading clinical sign, an atypical PrPSc signature and unusual fecal shedding of infectious prions. Importantly, these prions generated by the human PrP transgenic mice were transmissible upon passage. Our results are the first evidence of a zoonotic risk of CWD when using one of the most common CWD strains, Wisc-1/CWD1 for infection. We demonstrated in a human transgenic mouse model that the species barrier for transmission of CWD to humans is not absolute. The fact that its signature was not typical raises the questions whether CWD would manifest in humans as a subclinical infection, whether it would arise through direct or indirect transmission including an intermediate host, or a silent to uncovered human-to-human transmission, and whether current detection techniques will be suffcient to unveil its presence.
Our findings strongly suggest that CWD should be regarded as an actual public health risk. Here, we use humanized mice to show that CWD prions can cross the species barrier to humans, and remarkably, infectious prions can be excreted in feces.
Our results indicate that if CWD crosses the species-barrier to humans, it is unlikely to resemble the most common forms of human prion diseases with respect to clinical signs, tissue tropism and PrPSc signature. For instance, PrPSc in variable protease-sensitive prionopathy (VPSPr), a sporadic form of human prion disease, and in the genetic form Gerstmann-Sträussler-Scheinker syndrome (GSS) is defined by an atypical PK-resistant PrPSc fragment that is non-glycosylated and truncated at both C- and N-termini, with a molecular weight between 6 and 8 kDa [24, 44–46]. These biochemical features are unique and distinctive from PrPSc (PrP27-30) found in most other human or animal prion disease. The atypical PrPSc signature detected in brain homogenate of tg650 mice #321 (1st passage) and #3063 (2nd passage), and the 7–8 kDa fragment (Figs. 2, 4) are very similar to that of GSS, both in terms of migration profile and the N-terminal cleavage site.
CWD in humans might remain subclinical but with PrPSc deposits in the brain with an unusual morphology that does not resemble the patterns usually seen in different prion diseases (e.g., mouse #328; Fig. 3), clinical with untraceable abnormal PrP (e.g., mouse #327) but still transmissible and uncovered upon subsequent passage (e.g., mouse #3063; Fig. 4), or prions have other reservoirs than the usual ones, hence the presence of infectivity in feces (e.g., mouse #327) suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.
“suggesting a potential for human-to-human transmission and a real iatrogenic risk that might be unrecognizable.”
=================================
Supplementary Information The online version contains supplementary material available at
https://doi.org/10.1007/s00401-022-02482-9
snip...see full text;
https://link.springer.com/article/10.1007/s00401-022-02482-9
https://link.springer.com/content/pdf/10.1007/s00401-022-02482-9.pdf
Macaque tissues to rodent models demonstrates the zoonotic potential of chronic wasting disease.
Samia Hannaoui1,2, Ginny Cheng1,2, Wiebke Wemheuer3, Walter Schulz-Schaeffer3, Sabine Gilch1,2, Hermann Schatzl1,2 1University of Calgary, Calgary, Canada. 2Calgary Prion Research Unit, Calgary, Canada. 3Institute of Neuropathology, Medical Faculty, Saarland University, Homburg/Saar, Germany
Snip…
***> Further passage to cervidized mice revealed transmission with a 100% attack rate.
***> Our findings demonstrate that macaques, considered the best model for the zoonotic potential of prions, were infected upon CWD challenge, including the oral one.
****> The disease manifested as atypical in macaques and initial transgenic mouse transmissions, but with infectivity present at all times, as unveiled in the bank vole model with an unusual tissue tropism.
***> Epidemiologic surveillance of prion disease among cervid hunters and people likely to have consumed venison contaminated with chronic wasting disease
=====
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true
Transmission of Cervid Prions to Humanized Mice Demonstrates the Zoonotic Potential of CWD
Samia Hannaouia, Irina Zemlyankinaa, Sheng Chun Changa, Maria Immaculata Arifina, Vincent Béringueb, Debbie McKenziec, Hermann M. Schatzla, and Sabine Gilcha
Results: Here, we provide the strongest evidence supporting the zoonotic potential of CWD prions, and their possible phenotype in humans. Inoculation of mice expressing human PrPCwith deer CWD isolates (strains Wisc-1 and 116AG) resulted in atypical clinical manifestations in > 75% of the mice, with myoclonus as leading clinical sign. Most of tg650brain homogenates were positive for seeding activity in RT-QuIC. Clinical disease and presentation was transmissible to tg650mice and bank voles. Intriguingly, protease-resistant PrP in the brain of tg650 mice resembled that found in a familial human prion disease and was transmissible upon passage. Abnormal PrP aggregates upon infection with Wisc-1 were detectable in thalamus, hypothalamus, and midbrain/pons regions.
Unprecedented in human prion disease, feces of CWD-inoculated tg650 mice harbored prion seeding activity and infectious prions, as shown by inoculation of bank voles and tg650 with fecal homogenates.
Conclusions: This is the first evidence that CWD can infect humans and cause disease with a distinctive clinical presentation, signature, and tropism, which might be transmissible between humans while current diagnostic assays might fail to detect it. These findings have major implications for public health and CWD-management.
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
18. Zoonotic potential of moose-derived chronic wasting disease prions after adaptation in intermediate species
Tomás Barrioa, Jean-Yves Doueta, Alvina Huora, Séverine Lugana, Naïma Arona, Hervé Cassarda, Sylvie L. Benestadb, Juan Carlos Espinosac, Juan María Torresc, Olivier Andréolettia
aUnité Mixte de Recherche de l’Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement 1225 Interactions Hôtes-Agents Pathogènes, École Nationale Vétérinaire de Toulouse, 31076 Toulouse, France; bNorwegian Veterinary Institute, P.O. Box 64, NO-1431 Ås, Norway; cCentro de Investigación en Sanidad Animal (CISA-INIA), 28130, Valdeolmos, Madrid, Spain
Aims: Chronic wasting disease (CWD) is an emerging prion disease in Europe. To date, cases have been reported in three Nordic countries and in several species, including reindeer (Rangifer tarandus), moose (Alces alces) and red deer (Cervus elaphus). Cumulating data suggest that the prion strains responsible for the European cases are distinct from those circulating in North America. The biological properties of CWD prions are still poorly documented, in particular their spillover and zoonotic capacities. In this study, we aimed at characterizing the interspecies transmission potential of Norwegian moose CWD isolates.
Materials and Methods: For that purpose, we performed experimental transmissions in a panel of transgenic models expressing the PrPC sequence of various species.
Results: On first passage, one moose isolate propagated in the ovine PrPC-expressing model (Tg338). After adaptation in this host, moose CWD prions were able to transmit in mice expressing either bovine or human PrPC with high efficacy.
Conclusions: These results suggest that CWD prions can acquire enhanced zoonotic properties following adaptation in an intermediate species.
Funding
Grant number: AAPG2020 EU-CWD, ICRAD2020 TCWDE, NRC2022 NorCWD
Acknowledgement
https://www.tandfonline.com/doi/full/10.1080/19336896.2024.2424058
“ After adaptation in this host, moose CWD prions were able to transmit in mice expressing either bovine or human PrPC with high efficacy.”
TUESDAY, APRIL 07, 2026
APHIS USDA Captive CWD Herds Update by State March 2026
CHRONIC WASTING DISEASE CASES
Updated March 2026
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
Remember, a quarantined captive CWD Herd, is a ticking environmental time bomb just waiting to go off, think Chernobyl, the longer held in quarantine, the greater chance of environmental spread of CWD. litigation of CWD can take what seems to be an eternity, and CWD TSE Prion saturation into the environment grows each day left in quarantine. …terry
TUESDAY, APRIL 07, 2026
APHIS USDA Captive CWD Herds Update by State March 2026
https://chronic-wasting-disease.blogspot.com/2026/04/aphis-usda-captive-cwd-herds-update-by.html
Texas Chronic Wasting Disease CWD TSE Prion Progression 2012 to 2026, Positives to date 1282 confirmed
https://chronic-wasting-disease.blogspot.com/2026/03/texas-chronic-wasting-disease-cwd-tse.html
Control of Chronic Wasting Disease OMB Control Number: 0579-0189APHIS-2021-0004 Singeltary Submission
https://www.regulations.gov/comment/APHIS-2021-0004-0002
https://downloads.regulations.gov/APHIS-2021-0004-0002/attachment_1.pdf
Docket No. APHIS-2018-0011 Chronic Wasting Disease Herd Certification
https://www.regulations.gov/document/APHIS-2018-0011-0003
https://downloads.regulations.gov/APHIS-2018-0011-0003/attachment_1.pdf
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed
PUBLIC SUBMISSION
Comment from Terry Singeltary Sr.
Posted by the Food and Drug Administration on May 17, 2016 Comment
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission
https://www.regulations.gov/comment/FDA-2003-D-0432-0011
https://www.regulations.gov/docket/FDA-2003-D-0432
now, where was i?.. yes, genetic manipulation of the cervid to be less resistant to cwd, what could go wrong?
what im trying to converse here is, putting the TSE PrP cart before the cwd horse, BAD IDEA! TSE PrP properties can change when trying to manipulate genes, it’s just the nature of the beast. we know now, CWD will transmit to cattle, sheep, pigs, primates, and the only reason no documented link to humans has not been documented to date, there is no definitive diagnostic criteria set in stone as to make that definitive diagnosis, because imho, all studies to date show any link to cwd for humans shows a sporadic strain of sorts, study after study, NOT BSE, nvCJD. wild feral pigs have already shown susceptibility to CWD, in fact, the EU just released,, Chronic wasting disease prions in cervids and wild pigs in North America Preliminary Outbreak (see below). but science has shown, manipulating genes to be less resistant to TSE Prion, can have unforeseen circumstances, circumstances that are not always good, and in doing so, before extensive research, by releasing said genetic manipulated Cervid into the wild, you risk opening up a can of holy hell, you can’t put back in a can. why take that risk, it’s a bandaid approach to something that needs a tourniquet.
cwd can travel at 50 mph or so, FROM THE BACK OF A TRUCK, TRAILER!
stop trucking CWD!
Texas CWD Detected Mason County, Medina County, WTD Breeder, and Duval County, WTD Hunt, 2026
APHIS USDA Captive CWD Herds Update by State March 2026 Update
CHRONIC WASTING DISEASE CASES
Date of Index Case Confirmation Index Case State County Species Herd Type HCP Enrolled HCP Certified Number of Animals Herd Status
3/5/2026 2 YR Male PA Huntingdon WTD Elk Sika Hunt No No 100+ Quarantine
3/5/2026 1.5 YR Male TX Mason WTD Breeder No No 73 Quarantine
3/5/2026 2.5 YR Female TX Medina WTD Breeder No No 90 Quarantine
2/20/2026 2.75 YR Male MI Calhoun WTD Breeder Yes Yes 24 Quarantine
2/17/2026 2.5 YR Male KS Osage Axis Breeder No No 21 Quarantine
2/12/2026 3.5 YR TX Duval WTD Hunt No No ukn Quarantine
1/22/2026 3 YR Male PA Butler Elk Breeding Yes Yes 30 Quarantine
12/16/2025 Adults Male PA Indiana WTD elk Red deer Fallow Hunt No No ukn Quarantine
12/15/2025 3 YR Male PA Warren WTD Breeder No No >100 Quarantine
12/15/2025 4.5 YR Male PA Lycoming WTD ELK Hunt No No >100 Quarantine
12/15/2025 2.5 YR Male PA Juniata WTD Hobby No No 4 Quarantine
Updated March 2026
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
https://chronic-wasting-disease.blogspot.com/2026/04/aphis-usda-captive-cwd-herds-update-by.html
TUESDAY, APRIL 07, 2026
APHIS USDA Captive CWD Herds Update by State March 2026 Update
APHIS USDA Captive CWD Herds Update by State March 2026 Update
CHRONIC WASTING DISEASE CASES
Date of Index Case Confirmation Index Case State County Species Herd Type HCP Enrolled HCP Certified Number of Animals Herd Status
3/5/2026 2 YR Male PA Huntingdon WTD Elk Sika Hunt No No 100+ Quarantine
3/5/2026 1.5 YR Male TX Mason WTD Breeder No No 73 Quarantine
3/5/2026 2.5 YR Female TX Medina WTD Breeder No No 90 Quarantine
2/20/2026 2.75 YR Male MI Calhoun WTD Breeder Yes Yes 24 Quarantine
2/17/2026 2.5 YR Male KS Osage Axis Breeder No No 21 Quarantine
2/12/2026 3.5 YR TX Duval WTD Hunt No No ukn Quarantine
1/22/2026 3 YR Male PA Butler Elk Breeding Yes Yes 30 Quarantine
12/16/2025 Adults Male PA Indiana WTD elk Red deer Fallow Hunt No No ukn Quarantine
12/15/2025 3 YR Male PA Warren WTD Breeder No No >100 Quarantine
12/15/2025 4.5 YR Male PA Lycoming WTD ELK Hunt No No >100 Quarantine
12/15/2025 2.5 YR Male PA Juniata WTD Hobby No No 4 Quarantine
Updated March 2026
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
https://chronic-wasting-disease.blogspot.com/2026/04/aphis-usda-captive-cwd-herds-update-by.html
11/1/2025 ukn TX Limestone WTD Hunt No No 132 Quarantine
10/27/2025 3 YR Make WI Richland WTD Breeder Yes Yes ukn Quarantine
10/9/2025 2 YR Female TX Duvall WTD Breeder No No 94+ Quarantine
10/9/2025 2 YR Male PA Franklin WTD Breeder No No 23 Quarantine
10/8/2025 3.5 YR Male PA Huntingdon WTD Hobby No No 2 Quarantine
10/8/2025 3 YR Male WI Portage WTD Fallow Hunt No No 132 Quarantine
9/26/2025 8.5 YR Female TX Navaro WTD Breeder No No 650 Quarantine
9/16/2025 3 YR Female PA Dauphin WTD Breeder Yes Yes 85 Quarantine
9/5/2025 3 YR Male TX Duvall WTD Breeder No No 107+ Quarantine
8/6/2025 Adult Female PA Fulton WTD Breeder No No 14 Quarantine
7/21/2025 4 YR Female PA Bedford WTD Breeder No No 34 Quarantine
Updated December 2025 CHRONIC WASTING DISEASE CASES
6/3/2025 11 YR Female PA Blair WTD Breeder No No 45 Quarantine
6/3/2025 8 YR Female PA Bedford WTD Breeder No No 6 Quarantine
5/16/2025 5.5 YR Female WI Rock WTD Breeder No No ~46 Quarantine
5/14/2025 3 YR Female UT Weber Elk Hunt No No ukn Quarantine
4/30/2025 4.5 YR Male PA Jefferson WTD Hunt No No 36 Depopulated
4/18/2025 10+ YR Ukn TX Zavala WTD Hunt No No 190 Quarantine
4/9/2025 6 YR Male MI Montcalm WTD Breeder No No 86 Quarantine
3/28/2025 3.5 YR Male PA Huntingdon WTD Hobby No No 2 Quarantine
3/28/2025 3.5 YR Female PA Wayne Red Deer Hunt No no 31 Depopulated
2/26/2025 1.5 YR Male TX Kauffman WTD Breeder Yes Yes 400 Quarantine
2/26/2025 3.5 Yr Male PA Lancaster WTD Breeder Yes Yes 105 Quarantine
2/21/2025 4 YR Male CO Montrose Elk Hunt No No 97 Quarantine
Updated December 2025 CHRONIC WASTING DISEASE CASES
2/21/2025 7 YR Female MI Osceola WTD Hunt No No 201 Quarantine
2/10/2025 3.5 YR Male PA Perry WTD Hunt No No 15 Quarantine
1/7/2025 4 YR Female CO Mesa Elk Hunt No No 217 Quarantine
1/7/2025 2 YR Male UT Duchesne Elk Hunt No No 0 No animals
snip…see more;
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
Remember, a quarantined captive CWD Herd, is a ticking environmental time bomb just waiting to go off, think Chernobyl, the longer held in quarantine, the greater chance of environmental spread of CWD. litigation of CWD can take what seems to be an eternity, and CWD TSE Prion saturation into the environment grows each day left in quarantine. …terry
APHIS USDA Captive CWD Herds Update by State December 2025 Update
https://chronic-wasting-disease.blogspot.com/2025/12/aphis-usda-captive-cwd-herds-update-by.html
https://prpsc.proboards.com/thread/187/aphis-captive-herds-update-december
THURSDAY, MARCH 26, 2026
Texas Chronic Wasting Disease CWD TSE Prion Progression 2012 to 2026, Positives to date 1282 confirmed
https://chronic-wasting-disease.blogspot.com/2026/03/texas-chronic-wasting-disease-cwd-tse.html
TPW Commission Meeting CWD TSE PrP Transcript January 22, 2026 TEXAS PARKS AND WILDLIFE COMMISSION
Singeltary letter of concern on CWD 2026 submission
https://chronic-wasting-disease.blogspot.com/2026/03/tpw-commission-meeting-transcript-cwd.html
https://prpsc.proboards.com/thread/213/texas-chronic-wasting-disease-science
TPWD Commission Agenda Item 6 January 22, 2026
Chronic Wasting Disease Detection and Response Rules Recommended Adoption of Proposed Changes
https://prpsc.proboards.com/thread/192/tpwd-commission-agenda-january-detection
https://chronic-wasting-disease.blogspot.com/2026/01/tpwd-chronic-wasting-disease-detection.html
Texas Chronic Wasting Disease CWD TSE Prion Dashboard Update August 2025
SEE NEW DASHBOARD FOR CWD POSITIVES!
https://experience.arcgis.com/experience/8f6c27330c444a19b4b57beb7ffabb8b/page/Dashboard#data_s=id%3AdataSource_3-1966d773e34-layer-10%3A29
Texas CWD total by calendar years
https://chronic-wasting-disease.blogspot.com/2024/12/texas-cwd-tse-prion-positive-samples-by.html
https://tpwd.texas.gov/huntwild/wild/diseases/cwd/positive-cases/listing-cwd-cases-texas.phtml#texasCWD
Counties where CWD Exposed Deer were Released
https://tpwd.texas.gov/documents/257/CWD-Trace-OutReleaseSites.pdf
Number of CWD Exposed Deer Released by County
https://tpwd.texas.gov/documents/258/CWD-Trace-OutReleaseSites-NbrDeer.pdf
CWD Status Captive Herds
https://www.aphis.usda.gov/sites/default/files/status-of-captive-herds.pdf
Texas CWD total by calendar years
https://chronic-wasting-disease.blogspot.com/2024/12/texas-cwd-tse-prion-positive-samples-by.html
https://prpsc.proboards.com/thread/178/texas-game-wardens-conclusion-ghost
https://tpwd.texas.gov/huntwild/wild/diseases/cwd/positive-cases/listing-cwd-cases-texas.phtml#texasCWD
Trucking CWD TSE Prion
Chronic Wasting Disease CWD TSE Prion of Cervid
“CWD spreads among wild populations at a relatively slow rate, limited by the natural home range and dispersed nature of wild animals.”
NOW HOLD YOUR HORSES, Chronic Wasting Disease CWD of Cervid can spread rather swiftly, traveling around 50 MPH, from the back of truck and trailer, and Here in Texas, we call it ‘Trucking CWD’…
Preventive Veterinary Medicine Volume 234, January 2025, 106385
Use of biosecurity practices to prevent chronic wasting disease in Minnesota cervid herds
Vehicles or trailers that entered the farm were used to transport other live cervids, cervid carcasses, or cervid body parts in past 3 years in 64.3 % (95 % CI 46.3–82.3) of larger elk/reindeer herds compared to 13.6 % (95 % CI 4.7–22.4) of smaller deer herds.
Snip…
Identifying the exact pathway of initial CWD transmission to cervid herds is often not possible, in part due to many potential pathways of transmission for the infection, including both direct and indirect contact with infected farmed or wild cervids (Kincheloe et al., 2021). That study identified that transmissions from infected farmed cervids may occur from direct contact with the movement of cervids from one herd to another and from indirect contact with the sharing of equipment, vehicles, clothing, reproductive equipment, and potentially through semen or embryos.
https://www.sciencedirect.com/science/article/abs/pii/S016758772400271X
Texas is a fine example, see; “Chronic Wasting Disease (CWD) is a fatal neurological disease and can devastate deer populations by silently spreading through direct animal contact and contaminated environments. Without close monitoring, illegal movement of captive deer increases the risk of introducing CWD to areas it is not known to exist, potentially leading to widespread outbreaks which will impact more than just the health of Texas deer.”
https://tpwd.texas.gov/newsmedia/releases/?req=20250227b
THURSDAY, AUGUST 14, 2025
Texas Game Wardens Near Conclusion of ‘Ghost Deer’ Case with 24 Suspects, 1,400 Charges Filed Statewide
https://chronic-wasting-disease.blogspot.com/2025/08/texas-game-wardens-near-conclusion-of.html
https://prpsc.proboards.com/thread/178/texas-game-wardens-conclusion-ghost
Arkansas CWD Deer Study Final Report 2025
https://drive.google.com/file/d/1jN5mtvXvz7IYFDQjv4Rasrw60dGe4KMJ/view
This CWD Study Could Change Deer Hunting FOREVER | The Check Station October 8, 2025 NW Arkansas
NW Arkansas CWD 11:25 minutes;
50% of all deer positive for CWD.
35% of Does are Positive for CWD.
68% Bucks are Positive for CWD.
Most Bucks NW Arkansas that where Tested, are Positive for CWD.
https://m.youtube.com/watch?v=kTicUE-xsQU&t=695s&pp=2AG3BZACAQ%3D%3D
Southwest Wisconsin CWD, Deer and Predator Study
key takeaways ;
CWD substantially reduces deer survival rates and suppresses population growth.
Where CWD prevalence is high, deer populations are likely declining.
If CWD continues to spread, it will eventually impact deer populations elsewhere.
https://dnr.wisconsin.gov/topic/research/projects/dpp/StudyResults
***> CWD TSE PrP Environmental Factors <***
Chronic wasting disease (CWD) prion detection in environmental and biological samples from a taxidermy site and nursing facility, and instruments used in surveillance activities
Available online 9 April 2025
Highlights
• CWD prions were identified in a taxidermy and deer nursing facility.
• Contaminated samples included waters, soils, dermestid beetles, domestic flies and a dumpster.
• Surgical instruments used to collect deer samples can get contaminated with CWD prions.
• Some of the infectious particles are readily released from surgical instruments when washed.
• Our results suggest that taxidermy practices actively contribute in the spreading of CWD.
Snip…
In summary, the information provided in this report demonstrate how anthropogenic activities, specifically taxidermy practices, animal processing, and rehabilitation of CWD susceptible species, may facilitate CWD transmission through the environmental dissemination of CWD prions. This study, along with future research efforts characterizing the overall level of infectivity, provides relevant information on managing CWD and to control its rapid geographic expansion. …
https://www.sciencedirect.com/science/article/abs/pii/S0048969725009544
Chronic wasting disease detection in environmental and biological samples from a taxidermy site
Results: The PMCA analysis demonstrated CWD seeding activity in some of the components of this facility, including insects involved in head processing, soils, and a trash dumpster.
Conclusions: Different areas of this property were used for various taxidermy procedures. We were able to detect the presence of prions in
i) soils that were in contact with the heads of dead animals, ii) insects involved in the cleaning of skulls, and iii) an empty dumpster where animal carcasses were previously placed.
This is the first report demonstrating that swabbing is a helpful method to screen for prion infectivity on surfaces potentially contaminated with CWD. These findings are relevant as this swabbing and amplification strategy may be used to evaluate the disease status of other free-ranging and captive settings where there is a concern for CWD transmissions, such as at feeders and water troughs with CWD-exposed properties. This approach could have substantial implications for free-ranging cervid surveillance as well as in epidemiological investigations of CWD.
Prion 2022 Conference abstracts: pushing the boundaries
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
Artificial mineral sites that pre-date endemic chronic wasting disease become prion hotspots
The Ames Research and Educational Center property, centrally located within the CWD zone of southwest Tennessee, contains 49 historical mineral supplementation sites that were decommissioned in 2012. Here, we demonstrate that 32 of the 49 (65%) mineral sites within Ames established prior to the regional CWD outbreak, serve as foci of environmental PrPCWD contamination. Detection of PrPCWD in soils from these artificial mineral sites was dependent on site-specific management efforts. Soil physical properties were very similar across sites and no correlation between PrPCWD detection and soil physical properties was found. The detection of PrPCWD in soils at attractant sites within an endemic CWD zone significantly advances our understanding of environmental PrPCWD accumulation dynamics, providing valuable information for advancing adaptive CWD management approaches.
https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf
Shedding of Chronic Wasting Disease Prions in Multiple Excreta Throughout Disease Course in White-tailed Deer
Conclusions: These studies demonstrate: (a) CWD prion excretion occurs throughout infection; (2) PRNP genotype (GG≫GS/NT) influences the excreta shedding; and (3) detection sensitivity in excreta can vary with different RT-QuIC protocols. These results provide a more complete perspective of prion shedding in deer during the course of CWD infection.
Prion 2022 Conference abstracts: pushing the boundaries
https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286
"Additionally, we have determined that prion seeding activity is retained for at least fifteen years at a contaminated site following attempted remediation."
15 YEARS!
Detection of prions in soils contaminated by multiple routes
Results: We are able to detect prion seeding activity at multiple types of environmental hotspots, including carcass sites, contaminated captive facilities, and scrapes (i.e. urine and saliva). Differences in relative prion concentration vary depending on the nature and source of the contamination. Additionally, we have determined that prion seeding activity is retained for at least fifteen years at a contaminated site following attempted remediation.
Conclusions: Detection of prions in the environment is of the utmost importance for controlling chronic wasting disease spread. Here, we have demonstrated a viable method for detection of prions in complex environmental matrices. However, it is quite likely that this method underestimates the total infectious prion load in a contaminated sample, due to incomplete recovery of infectious prions. Further refinements are necessary for accurate quantification of prions in such samples, and to account for the intrinsic heterogeneities found in the broader environment.
Funded by: Wisconsin Department of Natural Resources
Meeting-book-final-version prion 2023 Prion 2023 Congress Organizing Committee and the NeuroPrion Association, we invite you to join us for the International Conference Prion2023 from 16-20 October 2023 in Faro, Portugal.
https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://web.archive.org/web/20250828201533/https://prion2023.org/wp-content/uploads/2023/10/Meeting-book-final-version2.pdf
https://www.researchgate.net/profile/Syed-Zahid-Shah/publication/378314391_Meeting-book-final-version_prion_2023/links/65d44dad28b7720cecdca95f/Meeting-book-final-version-prion-2023.pdf
***> Infectious agent of sheep scrapie may persist in the environment for at least 16 years
***> Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded.
JOURNAL OF GENERAL VIROLOGY Volume 87, Issue 12
Infectious agent of sheep scrapie may persist in the environment for at least 16 years Free
https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.82011-0
Rapid recontamination of a farm building occurs after attempted prion removal
First published: 19 January 2019 https://doi.org/10.1136/vr.105054
The data illustrates the difficulty in decontaminating farm buildings from scrapie, and demonstrates the likely contribution of farm dust to the recontamination of these environments to levels that are capable of causing disease. snip...
This study clearly demonstrates the difficulty in removing scrapie infectivity from the farm environment. Practical and effective prion decontamination methods are still urgently required for decontamination of scrapie infectivity from farms that have had cases of scrapie and this is particularly relevant for scrapie positive goatherds, which currently have limited genetic resistance to scrapie within commercial breeds.24 This is very likely to have parallels with control efforts for CWD in cervids.
https://bvajournals.onlinelibrary.wiley.com/doi/abs/10.1136/vr.105054
***>This is very likely to have parallels with control efforts for CWD in cervids.
https://pubmed.ncbi.nlm.nih.gov/30602491/
I remember what “deep throat” told me about Scrapie back around 2001, during early days of my BSE investigation, after my Mom died from hvCJD, I never forgot, and it seems it’s come to pass;
***> Confidential!!!!
***> As early as 1992-3 there had been long studies conducted on small pastures containing scrapie infected sheep at the sheep research station associated with the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are documented...I don't know. But personal recounts both heard and recorded in a daily journal indicate that leaving the pastures free and replacing the topsoil completely at least 2 feet of thickness each year for SEVEN years....and then when very clean (proven scrapie free) sheep were placed on these small pastures.... the new sheep also broke out with scrapie and passed it to offspring. I am not sure that TSE contaminated ground could ever be free of the agent!! A very frightening revelation!!!
---end personal email---end...tss
and so it seems…tss
CWD cash cow, indemnity?
‘cash cow’?
they call it indemnity, tax payers paying for captive CWD?
2025 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
APHIS works with State agencies to encourage cervid owners to certify their herds by meeting the requirements in the CWD Herd Certification Program (HCP) Standards. APHIS’ voluntary national CWD HCP helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds. Currently, 28 States participate in the national CWD HCP.
In 2023, eight percent of the farmed cervids in the HCP were tested for CWD at APHIS and State laboratories.
Of the 303,242 farmed cervids tested in 2023, APHIS confirmed 22 new CWD positive farmed cervid herds.
APHIS provided Federal indemnity to depopulate one of the newly identified positive herds and approved an indemnity payment for a second positive herd which will be provided in 2024 once depopulation occurs. The remaining infected herds are under State quarantines.
APHIS determines the use of Federal indemnity payments within the CWD program on a case-by-case basis. In 2023, APHIS made approximately $12.3 million available for cooperative agreements with States and Tribal governments to further develop and implement CWD surveillance, testing, management, and response activities. This includes the further development and evaluation of techniques and strategies to prevent or control CWD in farmed and wild cervid populations. APHIS funded cooperative agreement with 22 States, 15 universities, and 11 Tribes and Tribal Organizations for CWD projects…
https://www.usda.gov/sites/default/files/documents/22-APHIS-2025-ExNotes.pdf
2024 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
APHIS works with State agencies to encourage cervid owners to certify their herds by meeting the requirements in the CWD Herd Certification Program (HCP) Standards. APHIS’ voluntary national CWD HCP helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds.
Currently, 28 States participate in the national CWD HCP.
In 2022, 7 percent of the 285,589 farmed cervids in the HCP participating states were tested for CWD at State and APHIS laboratories.
APHIS confirmed 23 new CWD positive farmed cervid herds.
APHIS provided Federal indemnity to depopulate nine of the newly identified positive herds in 2022. The remaining infected herds are under State quarantines. APHIS determines the use of Federal indemnity payments within the CWD program on a case-by-case basis. In 2022, APHIS made approximately $9.4 million available for cooperative agreements with States and Tribal governments to further develop and implement CWD surveillance, testing, management, and response activities. This includes the further development and evaluation of techniques and strategies to prevent or control CWD in farmed and wild cervid populations. APHIS funded 27 States and 5 Tribes, 1 Tribal Organization, and 1 State university. The State university agreement was to conduct wild cervid surveillance on Tribal lands…
https://www.usda.gov/sites/default/files/documents/23-2024-APHIS.pdf
2023 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
APHIS coordinates with State agencies to encourage cervid owners to certify their herds and comply with the CWD Herd Certification Program (HCP) Standards…
APHIS’ voluntary national CWD HCP helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds.
Currently, 28 States participate in the national CWD HCP. In FY 2021, more than 20,502 farmed cervids were tested for CWD at State and APHIS laboratories.
As a result, APHIS identified 35 new CWD positive farmed cervid herds.
APHIS provided Federal indemnity to depopulate nine of the newly identified deer herds in FY 2021. The remaining infected herds are under State quarantines. APHIS determines the use of Federal indemnity payments within the CWD program on a case-by-case basis. In 2021, APHIS made $5.6 million available in cooperative agreement funding to further develop and implement CWD surveillance, testing, management, and response activities, including the further development and evaluation of techniques and strategies to prevent or control CWD in farmed and wild cervid populations. APHIS funded awards to 39 entities: 20 to State Departments of Wildlife, 11 to State Departments of Agriculture, and 8 to Tribal Organizations.
https://www.usda.gov/sites/default/files/documents/23-2023-APHIS.pdf
2022 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
APHIS coordinates with State agencies to encourage cervid owners to certify their herds and comply with the CWD Herd Certification Program Standards…
APHIS’ voluntary national CWD Herd Certification Plan (HCP) helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds.
Currently, 28 States participate in the national CWD HCP. In FY 2020, more than 11,182 farmed cervids were tested for CWD at State and APHIS laboratories.
As a result, APHIS identified 22 new CWD positive farmed cervid herds.
APHIS provided Federal indemnity to depopulate 15 of the 22 newly identified deer herds in FY 2020.
Four additional farmed cervid herds that were identified as CWD positive herds in FY 2019, were indemnified in FY 2020.
The remaining infected herds are under State quarantines.
APHIS determines the use of Federal indemnity payments within the CWD program on a case- by-case basis. In FY 2020, APHIS and the Department of Interior held a virtual summit with representatives from State agriculture and wildlife agencies, Tribal Nations, conservation and hunting groups, and the cervid industry to identify and discuss stakeholder CWD management needs and information gaps that need to be addressed to effectively control CWD. The information from the summit helped APHIS establish priorities for proposals for competitive cooperative agreements dedicated to CWD control. These cooperative agreement opportunities allow for State departments of agriculture, State animal health agencies, State departments of wildlife or natural resources, and Tribal governments to further develop and implement CWD management and response activities in accordance with the following priorities:
• improving CWD management of affected farmed herds and free-ranging endemic populations;
• improving CWD management of affected areas or premises;
• conducting additional research on amplification assays;
• conducting additional research on predictive genetics; and,
• developing and/or delivering educational outreach materials or programs.
To execute projects based upon those priorities, APHIS funded awards to 25 entities:
19 to State Departments of Natural Resources, 5 to State Departments of Agriculture, and 1 to Tribal Nations.
https://www.usda.gov/sites/default/files/documents/22APHIS2022Notes.pdf
2021 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
In FY 2019, 10 mule deer were tested as part of the project and all 10 tested negative.
Currently, 28 States participate in APHIS’ voluntary national CWD Herd Certification Plan (HCP).
In FY 2019 APHIS tested more than 11,000 farmed cervids for CWD.
As a result, APHIS identified 17 new CWD positive farmed cervid herds.
APHIS provided Federal indemnity to depopulate 7 of the 17 newly identified deer herds in FY 2019. The remaining infected herds found in FY 2019 are under State quarantines.
https://www.usda.gov/sites/default/files/documents/20aphis2021notes.pdf
2020 USDA EXPLANATORY NOTES – ANIMAL AND PLANT HEALTH INSPECTION SERVICE
Cervids
APHIS’ voluntary national CWD Herd Certification Plan (HCP) helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds.
Currently, 28 States participate in the national CWD HCP and the program used an immunohistochemistry test method to test 21,584 farmed cervids for CWD.
In FY 2018, APHIS identified 15 new CWD positive farmed cervid herds (14 deer herds and 1 reindeer herd).
The reindeer herd in Illinois was the first confirmed case of CWD in a reindeer in North America.
APHIS provided Federal indemnity to depopulate seven of the 15 newly identified deer herds in FY 2018.
The Agency also provided funding for the test and removal of 161 high risk animals that were in close proximity to reactors.
The remaining herds in FY 2018 are under State quarantines.
The Agency determines the use of Federal indemnities within the CWD program on a case-by-case basis. 20-59
https://www.usda.gov/sites/default/files/documents/20aphis2020notes.pdf
2019 President’s Budget Animal and Plant Health Inspection Service
Cervids
APHIS’ voluntary national CWD Herd Certification Plan (HCP) helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds.
Currently, 28 States participate in the national CWD HCP and the program tested 23,053 farmed cervids for CWD.
In FY 2017, eight new CWD positive farmed cervid herds were identified– one white-tail deer in Iowa, one white-tail deer herd in Minnesota, one white-tail and mule deer herd in Minnesota, one white-tail and sika deer herd in Michigan, three white-tail deer herds in Pennsylvania, and one white-tail deer herd in Texas.
APHIS provided Federal indemnity to depopulate the Iowa herd, the white-tail deer herd in Minnesota, one herd in Pennsylvania and the Texas herd. The State depopulated the Michigan herd. The remaining herds are under State quarantines. One Texas herd used Federal indemnity to remove and test select, high-risk animals to inform the epidemiological investigation and to evaluate the performance of ante-mortem tests.
The Agency determines the use of Federal indemnities within the CWD program on a case-by-case basis. The CWD Program Standards provide guidance on how to meet CWD Herd Certification Program and interstate movement requirements. In July 2016, APHIS convened a working group of State and Federal animal health and wildlife officials and representatives from the farmed cervidae industry to review the CWD Program Standards. APHIS issued a summary of the working group’s discussions and recommended changes to the CWD Program Standards at the 2016 United States Animal Health Association meeting for public comment. APHIS evaluated public comments, and is currently reviewing revisions to the CWD Program. In FY 2017, APHIS published VS Guidance 8000: Requirements for Interstate Transport of Wild Caught Cervids. This guidance document establishes a recommended minimum standard for testing and a uniform process of disease risk assessment to help prevent the spread of cervid diseases such as chronic wasting disease (CWD), bovine tuberculosis (TB), and brucellosis when wild cervids are captured for interstate movement and release.
https://www.usda.gov/sites/default/files/documents/20aphis2019notes.pdf
2018 President’s Budget Animal and Plant Health Inspection Service
Cervids
APHIS’ voluntary national CWD Herd Certification Plan (HCP) helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds considered to be low risk.
Currently, 29 States participate in the national CWD HCP.
In FY 2016, the program tested 14,503 farmed cervids for CWD and identified seven new CWD positive farmed cervid herds – two white-tail deer herds in Texas, three white-tail deer herds in Wisconsin, one elk herd in Colorado and one elk herd in Iowa. The elk herd in Colorado was depopulated without Federal indemnity and the rest of the herds are under State quarantines. One Texas herd used Federal indemnity to remove and test select animals to inform the epidemiological investigation and to evaluate 20-72 the performance of ante-mortem tests.
The use of Federal indemnities within the CWD program is determined on a case-by-case basis. APHIS is also conducting several pilot projects related to new technologies. In FY 2016, the Agency sponsored a pilot project in Ohio to evaluate the use of a new method for ante-mortem testing in whitetail deer known as rectoanal mucosa associated lymphoid tissue or RAMALT testing. A proof-of-concept pilot project was also performed by APHIS’ National Veterinary Services Laboratories (NVSL) to evaluate ante-mortem biopsies of the medial retropharyngeal lymph node biopsy or MRPLN biopsy. APHIS anticipates implementing both types of ante- mortem testing in the future. Beginning early September 2014, APHIS, in cooperation with the National Agricultural Statistics Service, conducted the first national study of the U.S. farmed cervid industry. The study surveyed 3,000 producers from all States that have farmed cervids. The study provides baseline industry statistics, a description of current production practices and challenges, producer-reported disease occurrences, and an overview of health management and biosecurity practices. A report from the study is now available in electronic and printed formats at: http://www.aphis.usda.gov/nahms.
https://www.usda.gov/sites/default/files/documents/20aphisexnotes2018.pdf
2017 Explanatory Notes Animal and Plant Health Inspection Service
Cervids
APHIS’ voluntary national CWD Herd Certification Plan (HCP) helps States, Tribes, and the cervid industry control CWD in farmed cervids by allowing the interstate movement only from certified herds considered to be low risk.
Currently, 30 States participate in the national CWD HCP: 29 have Approved Status and 1 has Provisional Approved Status. States that meet the CWD HCP requirements have Approved Status and States that do not meet CWD HCP program requirements but have developed a work plan and time frame with APHIS to complete those requirements have Provisional Approved Status.
In FY 2015, the program tested approximately 20,000 farmed cervids for CWD and identified eight new CWD positive farmed white-tailed deer herds – one in Utah, one in Pennsylvania, two in Ohio, two in Wisconsin, and two in Texas.
APHIS depopulated five of these herds (Pennsylvania, Utah, and one each in Wisconsin, Texas, and Ohio). Six elk herds in Colorado, four elk herds in Nebraska, one white-tailed deer herd in Wisconsin and one white-tailed deer herd in Texas remained in quarantine at the end of FY 2015.
APHIS also provided indemnity for and was the lead agency for the depopulation and disposal of four large CWD infected farmed cervid herds in Pennsylvania, Ohio, Utah, and Texas. In cooperation with the National Agricultural Statistics Service, APHIS conducted the first national study of the U.S. farmed-cervid industry in FY 2015. The study provides baseline industry statistics, a description of production practices and challenges, producer-reported disease occurrences, and an overview of health management and biosecurity practices.
https://www.usda.gov/sites/default/files/documents/20aphis2017notes.pdf
2016 Explanatory Notes Animal and Plant Health Inspection Service
https://www.usda.gov/sites/default/files/documents/20aphis2016notes.pdf
2015 Explanatory Notes Animal and Plant Health Inspection Service
https://www.usda.gov/sites/default/files/documents/20aphis2015notes.pdf
2014 Explanatory Notes Animal and Plant Health Inspection Service
https://www.usda.gov/sites/default/files/documents/18aphis2014notes.pdf
USDA EXPLANATORY NOTES ANIMAL AND PLANT HEALTH INSPECTION SERVICE 2025-2014 CHRONIC WASTING DISEASE CWD TSE CERVID
https://chronic-wasting-disease.blogspot.com/2025/09/usda-explanatory-notes-animal-and-plant.html
FRIDAY, OCTOBER 31, 2025
Captive Cervid and the Economic Burden of Chronic Wasting Disease CWD TSE Prion?
https://chronic-wasting-disease.blogspot.com/2025/10/captive-cervid-and-economic-burden-of.html
https://prpsc.proboards.com/thread/183/captive-cervid-economic-burden-prion
APHIS USDA Captive CWD Herds Update by State December 2025 Update
https://chronic-wasting-disease.blogspot.com/2025/12/aphis-usda-captive-cwd-herds-update-by.html
https://prpsc.proboards.com/thread/187/aphis-captive-herds-update-december
MONDAY, FEBRUARY 23, 2026
***> Chronic Wasting Disease CWD TSE Prion, Economical, Environmental, Zoonotic, Risk Factors 2026 <***
https://transmissiblespongiformencephalopathy.blogspot.com/2026/02/chronic-wasting-disease-cwd-tse-prion.html
ARS Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies 2025
“ARS researchers in Ames, Iowa, showed that white-tailed deer sick with scrapie from sheep can infect other deer under conditions mimicking natural exposure. Furthermore, this work shows that CWD is difficult to differentiate from WTD infected with scrapie. WTD scrapie prions accumulate in the lymphoreticular system in a manner similar to CWD, meaning that environmental contamination may occur through feces, saliva, and other body fluids of scrapie affected WTD as has been shown for CWD. The presence of WTD infected with scrapie could confound mitigation efforts for chronic wasting disease. This information informs regulatory officials, the farmed cervid industry, and officials tasked with protecting animal health such as state Departments of Agriculture, Natural Resources, or Parks and Wildlife with regard to a disease similar to CWD but arising from sheep scrapie that could be present in WTD that have contact with scrapie affected sheep and/or goats.”
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
2025 Annual Report
Objectives
Objective 1: Develop highly sensitive detection tools to determine the distribution of CWD and scrapie prions in natural hosts (sheep, goats, cervids) and their environment.
Objective 2: Investigate the pathobiology of CWD, scrapie prion strains, and atypical TSEs in natural hosts including potential cross species transmission events.
Objective 3: Investigate the genetics of CWD susceptibility and resistance in white-tailed deer.
Objective 4: Evaluate the presence of and determine the appropriate methodology for CWD strain determination.
Approach
Eradication or control of a family of diseases is unlikely or impossible when an understanding of the basic mechanisms and influences on transmission are unknown and for which methods to evaluate disease status are lacking. Scrapie and BSE represent the most thoroughly studied TSEs; however, significant knowledge gaps persist with regard to the atypical variants of these diseases. Further, much of the research emphasis to date on genetics of prion disease has focused on the recipient genotype rather than the source. Since both atypical BSE and atypical scrapie have been suggested to occur spontaneously, eradication of these diseases may not be possible unless we expand our understanding of the disease at both the source and recipient level. A better understanding of the tissue distribution and potential transmission of these atypical isolates is critical to understanding what risk these disease variants may pose to ongoing control and eradication efforts. The European epizootic of BSE is waning and efforts to eradicate scrapie in the U.S. and abroad have progressed but are not complete. In the U.S., chronic wasting disease (CWD) presents the most serious challenge to regulatory efforts. CWD appears to be spreading unchecked in both free-ranging and farmed cervids. Methods for antemortem detection of TSEs in general and CWD in particular are needed to fulfill the goal of eradicating scrapie and controlling CWD. Performing these studies will allow us to address critical knowledge gaps that are relevant to developing measures to restrict further disease expansion beyond current, affected populations. Understanding prion disease persistence in animal populations is challenging due to lack of tools for study and a less than complete understanding of transmission among animals within a flock or herd or in naturally occurring reservoirs. In addition to transmission between hosts of like species, free-ranging cervids may come in contact with numerous other species including cattle, sheep, and other susceptible hosts. Transmission of CWD to other species has been studied but limited with regard to the source genotype used. The four primary objectives are inherently linked. Our focus is on developing tools needed for control and research, and using those tools to advance our understanding the complex disease process with the overall goal of eradication and control of disease in livestock, wildlife of economic importance, and potential wildlife reservoirs.
Progress Report
The goals of the project plan for fiscal year (FY) 2025 consisted of 12 milestones, 11 of which were either fully or substantially met. The only milestone in this plan that was not met was due to insufficient animal availability and space constraints. Previous studies utilizing this space are not complete due to longer than anticipated incubation periods and cannot be initiated until those studies are complete. In work toward addressing
Objective 1, “Develop highly sensitive detection tools to determine the distribution of chronic wasting disease (CWD) and scrapie prions in natural hosts (sheep, goats, cervids) and their environment”, we have worked closely with ARS researchers in Pullman, Washington, Animal and Plant Health Inspection Service (APHIS), and university partners. The tools under development are directly utilized by state diagnostic labs and have been shared with the appropriate end users for evaluation. We have also assessed alternative dyes that have do not induce amyloid formation in the amplification based diagnostic assay known as RT-QuIC. While no increase in sensitivity was observed, differences between strains were found offering an additional means to differentiate strains for some TSEs.
Objective 2, “Investigate the pathobiology of CWD, scrapie prion strains, and atypical TSEs in natural hosts including potential cross species transmission events”, the studies in question have been initiated with the goal of furthering the understanding of these TSEs in agriculturally relevant species including the natural host species and other that may be exposed to these TSEs in an agricultural environment. The studies are ongoing and anticipated to last upwards of 5 year and observation of the animals is ongoing. No anticipated signs of disease or relevant reportable information have been seen nor are they expected until near the onset of clinical signs, but if they are observed they will be reported.
Objective 3, “Investigate the genetics of CWD susceptibility and resistance in white-tailed deer”, consists of two subobjectives:
A) Investigate the susceptibility of white-tailed deer to CWD modeling direct contact exposure with infected deer, and
B) Investigate the susceptibility of white-tailed deer to CWD after direct inoculation.
The first of these has been initiated on schedule while the second has been delayed considerably (greater than 3 years at this point) due to insufficient animal space.Upon completion these two studies will aid in understanding the disease and disease progression.
Objective 4, “Evaluate the presence of and determine the appropriate methodology for CWD strain determination”, is dependent upon obtaining a diverse set of CWD isolates. We are continuing the acquisition of these samples. . Strains are one of the least understood aspects of TSEs as a whole and of importance in understanding the risks of CWD. We have initiated studies that will address the biochemical nature of prion strains and how these strains are maintained in a host which will aid in addressing features and differentiation of strains as additional samples become available.
Accomplishments
1. 01 Determined that white-tailed deer (WTD) infected with scrapie from sheep can transmit the disease to other deer under conditions mimicking natural exposure. It has long been suggested that prion disease in deer (chronic wasting disease (CWD)) was caused by the prion agent from sheep. The prion disease that affects sheep, scrapie, has been recognized for hundreds of years. However, chronic wasting disease, a similar disease found in WTD, has only been recognized since the 1960s. ARS researchers in Ames, Iowa, showed that white-tailed deer sick with scrapie from sheep can infect other deer under conditions mimicking natural exposure. Furthermore, this work shows that CWD is difficult to differentiate from WTD infected with scrapie. WTD scrapie prions accumulate in the lymphoreticular system in a manner similar to CWD, meaning that environmental contamination may occur through feces, saliva, and other body fluids of scrapie affected WTD as has been shown for CWD. The presence of WTD infected with scrapie could confound mitigation efforts for chronic wasting disease. This information informs regulatory officials, the farmed cervid industry, and officials tasked with protecting animal health such as state Departments of Agriculture, Natural Resources, or Parks and Wildlife with regard to a disease similar to CWD but arising from sheep scrapie that could be present in WTD that have contact with scrapie affected sheep and/or goats.
2. 02 Showed that gene-targeted mice are capable of reproducing strain specific effects typically limited to natural host species of chronic wasting disease (CWD). CWD is a highly contagious disease of deer, elk, moose, and reindeer found in North America, South Korea, and Scandinavian countries that is caused by misfolded proteins called prions. CWD prions transmit through direct contact between infected animals, or through contaminated soil, grass, or water. All prion diseases exhibit progressive neurodegeneration and ultimately death. Scientists typically study CWD by injecting prions into susceptible animals' brains in lab experiments. Intracranial prion injections are favored because they typically produce shorter incubation periods and higher disease attack rates compared to natural infection. ARS researchers in Ames, Iowa, along with university collaborators showed that this inoculation method can cause the prion strains to change in a way that does not accurately reflect how the disease spreads naturally. They found that using a combination of peripheral inoculation (injection outside the brain) in natural hosts and using novel gene-targeted mice generated in a manner that provides a more natural expression of the inserted prion gene that gives a more accurate picture of how CWD behaves in the real world. The novel mouse model provides an important strategy to precisely assess the zoonotic potential (likelihood of transmission from animals to humans) of CWD and other animal prion diseases using natural routes of transmission. This will impact the tools used and direction of future studies of CWD and other prion diseases allowing more rapid and comprehensive responses to emerging questions aiding both the researchers at the producers they support…end
https://www.ars.usda.gov/research/project/?accnNo=440677&fy=202
Chronic Wasting Disease CWD vs Scrapie TSE Prion
Volume 30, Number 8—August 2024
Research
Scrapie Versus Chronic Wasting Disease in White-Tailed Deer
Zoe J. Lambert1, Jifeng Bian, Eric D. Cassmann, M. Heather West Greenlee, and Justin J. Greenlee
Author affiliations: Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA (Z.J. Lambert); US Department of Agriculture, Ames, Iowa, USA (Z.J. Lambert, J. Bian, E.D. Cassmann, J.J. Greenlee); Iowa State University, Ames (Z.J. Lambert, M.H. West Greenlee) Suggested citation for this article
Abstract
White-tailed deer are susceptible to scrapie (WTD scrapie) after oronasal inoculation with the classical scrapie agent from sheep. Deer affected by WTD scrapie are difficult to differentiate from deer infected with chronic wasting disease (CWD). To assess the transmissibility of the WTD scrapie agent and tissue phenotypes when further passaged in white-tailed deer, we oronasally inoculated wild-type white-tailed deer with WTD scrapie agent. We found that WTD scrapie and CWD agents were generally similar, although some differences were noted. The greatest differences were seen in bioassays of cervidized mice that exhibited significantly longer survival periods when inoculated with WTD scrapie agent than those inoculated with CWD agent. Our findings establish that white-tailed deer are susceptible to WTD scrapie and that the presence of WTD scrapie agent in the lymphoreticular system suggests the handling of suspected cases should be consistent with current CWD guidelines because environmental shedding may occur.
snip…
The potential for zoonoses of cervid-derived PrPSc is still not well understood (6,18,45–47); however, interspecies transmission can increase host range and zoonotic potential (48–50). Therefore, to protect herds and the food supply, suspected cases of WTD scrapie should be handled the same as cases of CWD.
https://wwwnc.cdc.gov/eid/article/30/8/24-0007_article
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
2025 Annual Report
https://transmissiblespongiformencephalopathy.blogspot.com/2025/12/ars-research-elucidating-pathobiology.html
Oklahoma ANOTHER CWD-INFECTED MULE DEER FOUND IN CIMARRON COUNTY
rod.hall@ag.ok.gov, micah.holmes@odwc.ok.gov
ANOTHER CWD-INFECTED MULE DEER FOUND IN CIMARRON COUNTY February 6, 2026
A hunter-harvested mule deer from Cimarron County in Oklahoma’s Panhandle has tested positive for chronic wasting disease (CWD), and the Oklahoma Department of Wildlife Conservation (ODWC) has activated the CWD Response Plan jointly produced with the Oklahoma Department of Agriculture, Food and Forestry. This latest CWD-positive deer was harvested about 3.5 miles west of Felt, near the location where a CWD-positive deer was confirmed last year.
“The CWD Response Plan dictates that we respond to this finding by establishing a Selective Surveillance Area” said Joey McAllister, Wildlife Programs Supervisor with ODWC.
Since this latest infected animal was taken so close to the previous one, the current SSA in Cimarron County will remain unchanged; no new area will be added.
“We will be working through our response plan, and our ultimate goal is to ensure healthy and well-managed deer with as little impact to either the resource or our constituents as possible,” McAllister said.
CWD is an always-fatal neurological disease that affects the brains of deer, elk, moose, and other members of the cervid family, creating holes resembling those in sponges. CWD transmission from wild animals to people or to livestock has never been documented. Oklahoma's first case of a wild deer infected with CWD was confirmed in June 2023 in Texas County in Oklahoma’s Panhandle.
The Wildlife Department has conducted CWD monitoring on hunter-harvested deer and elk, and road-killed deer, since 1999.
ODWC staff will continue monitoring for evidence of CWD within Oklahoma’s borders and will release additional information, including ways deer and elk hunters can help with detection and mitigation. Additional guidelines or management plans will be distributed and well-advertised if determined necessary to further protect Oklahoma’s deer and elk populations.
For more information on the disease, hunting regulations, and proper disposal of infected animals, go to https://www.wildlifedepartment.com/hunting/resources/deer/cwd. Additional human health information relating to CWD is available at https://www.usgs.gov/centers/nwhc/publications. Image Cimarron County SSA map Feb 2026 This map shows the CWD Selective Surveillance Area in Cimarron County.
https://www.wildlifedepartment.com/sites/default/files/styles/width_768/public/2026-02/cim%20co%20ssa_0.jpg.webp?itok=Qj5PPAp1
https://www.wildlifedepartment.com/outdoor-news/another-cwd-infected-mule-deer-found-cimarron-county
Oklahoma fourth case of a wild deer infected with Chronic Wasting Disease
A fourth case of a wild deer infected with Chronic Wasting Disease has prompted the Oklahoma Department of Wildlife Conservation to expand its existing Selective Surveillance Area (SSA) for CWD in Texas County westward and southward.
New CWD-Positive Wild Deer Confirmed in Oklahoma Oklahoma's fourth case of a wild deer infected with Chronic Wasting Disease (CWD) was confirmed this month in the Oklahoma Panhandle. The white-tailed deer was located in Texas County after a landowner reported the animal behaving abnormally.
CWD is an always-fatal neurological disease that affects deer, elk, moose, and other members of the cervid family, creating holes in the brain resembling those in sponges. As part of the state's CWD Response Strategy, the confirmation has prompted the Oklahoma Department of Wildlife Conservation to expand the existing Selective Surveillance Area (SSA) for chronic wasting disease in Texas County westward and southward. The CWD Response Strategy is a plan jointly produced by the Wildlife Department along with the Oklahoma Department of Agriculture, Food and Forestry.
Hunters who harvest a deer within the SSA boundary must comply with specific regulations for handling and moving deer and other cervid parts outside the area. These boundary changes, along with cervid transport rules within an SSA, can be viewed at wildlifedepartment.com/hunting/resources/deer//cwd/ssa.
The site also includes information about voluntary testing sites in Oklahoma's three active SSAs. Dispersed across SSAs in northwestern Oklahoma, the testing sites are locations where hunters may choose to leave the head of their harvested deer or elk to be tested for CWD.
"The Wildlife Department is implementing its response plan to monitor and slow the potential spread of CWD," said Dallas Barber, wildlife biologist over big game for the Wildlife Department. "Our priority is to continue to ensure the health and management of our deer herd in Oklahoma, and the steps in our CWD Response Strategy will help us do that."
The Wildlife Department has conducted CWD monitoring on hunter-harvested deer and elk and road-killed deer since 1999 following the discovery of the disease in a private, commercial elk herd in 1998.
The first in-state CWD case in free-ranging deer was confirmed in June 2023 in Texas County.
CWD does not affect pronghorn antelope, and natural CWD transmission from wild animals to humans or livestock has never been documented. Additional human health information relating to CWD is available at https://www.usgs.gov/centers/nwhc/science/chronic-wasting-disease#publications. For more information on the disease, hunting regulations, and proper disposal of infected animals, go to https://www.wildlifedepartment.com/hunting/resources/deer/cwd.
https://wildlifedepartment.com/hunting/resources/deer/cwd
https://content.govdelivery.com/accounts/OKDWC/bulletins/3ee61ca?reqfrom=share
“CWD does not affect pronghorn antelope, and natural CWD transmission from wild animals to humans or livestock has never been documented.”
Please See;
Chronic wasting disease prions in cervids and wild pigs in North America Preliminary Outbreak Assessment DEFRA 26 January 2026
CWD has continued to spread among captive and free-ranging cervids in North America since it was first detected in the 1960s. The finding of CWD prions in wild pigs in the USA suggests they could contribute towards transmission of the disease, influencing its epidemiology, geographic distribution and interspecies spread. However, further research is needed to confirm this. CWD has never been reported in Great Britain and the current risk of CWD prions being introduced into Great Britain’s wild pig or cervid population ranges from very low to negligible.
https://assets.publishing.service.gov.uk/media/697a3b013c71d838df6bd413/CWD_Prions_in_Cervids_and_Wild_Pigs_in_North_America.pdf
see more on cwd transmitting to pigs, cattle, sheep, by oral route, below, very disturbing, and why…terrible news…terry
ATTENTION Cimarron, Texas, Woodward, Major, and Woods County Hunters
Two CWD-positive cases were confirmed in recent months in Oklahoma: one in Texas County about 4 miles north of Optima Wildlife Management Area, and another about 15 miles east of Woodward.
ODWC’s response plan in cooperation with the Oklahoma Department of Agriculture, Food and Forestry is to contain CWD within areas where it is detected and to minimize its artificial spread to other areas by establishing selective surveillance areas (SSA).
Previously, ODWC was notified by the Texas Parks & Wildlife Department (TPWD) of a road-killed deer infected with chronic wasting disease (CWD) found 2.5 miles south of the Oklahoma-Texas border near Felt, Okla., in southwestern Cimarron County.
https://www.wildlifedepartment.com/hunting/resources/deer/cwd/ssa
SECOND CWD-POSITIVE WILD DEER CONFIRMED IN OKLAHOMA A second wild white-tailed deer has tested positive for chronic wasting disease (CWD) in Oklahoma.
The deer was located about 15 miles east of Woodward in Woodward County after a landowner reported the deer behaving abnormally.
Oklahoma's first case of a wild deer infected with CWD was confirmed the first week of June in Texas County, prompting the activation of the next stage in the state's CWD Response Strategy jointly produced by the Oklahoma Department of Wildlife Conservation and the Oklahoma Department of Agriculture, Food and Forestry.
“We will be working through our response plan implementing surveillance efforts and steps to monitor and slow the potential spread of this disease. Our ultimate goal is to ensure healthy and well-managed deer with as little impact to either the resource or our constituents as possible,” said Jerry Shaw, Wildlife Programs Supervisor with ODWC.
CWD is an always-fatal neurological disease that affects the brains of deer, elk, moose, and other members of the cervid family, creating holes resembling those in sponges. CWD transmission from wild animals to people or to livestock has never been documented.
The Wildlife Department has conducted CWD monitoring on hunter-harvested deer and elk, and road-killed deer, since 1999.
Department staff will continue monitoring for evidence of CWD within Oklahoma’s borders and will release additional information, including ways deer and elk hunters can help with detection and mitigation, as hunting seasons approach.
Additional guidelines or management plans will be distributed and well-advertised if determined necessary to further protect Oklahoma’s deer and elk populations.
Additional human health information relating to CWD is available at https://www.usgs.gov/centers/nwhc/science/chronic-wasting-disease#publications.
For more information on the disease, hunting regulations, and proper disposal of infected animals, go to
https://www.wildlifedepartment.com/hunting/resources/deer/cwd.
https://www.wildlifedepartment.com/outdoor-news/second-cwd-positive-wild-deer-confirmed-oklahoma
CHRONIC WASTING DISEASE CONFIRMED IN ONE FARMED OKLAHOMA ELK
JOINT RELEASE FROM THE OKLAHOMA DEPARTMENT OF AGRICULTURE, FOOD & FORESTRY AND THE OKLAHOMA DEPARTMENT OF WILDLIFE CONSERVATION
OKLAHOMA CITY — An elk from a farmed herd in Lincoln County has tested positive for chronic wasting disease (CWD), according to the Oklahoma Department of Agriculture, Food & Forestry (ODAFF) and the Oklahoma Department of Wildlife Conservation.
The 2-year-old bull elk died as the result of an injury. The elk was tested through routine surveillance in compliance with the breeding facility’s Certified Herd Plan.
CWD is a fatal neurological disease that affects the brains of elk, deer and other cervid species. No vaccine or treatment for the disease exists. Importantly, no health risk to humans or non-cervid livestock has been documented.
ODAFF has quarantined the farmed breeding facility, and the Wildlife Department will be testing wild deer in the area near the facility for the presence of CWD. The adjacent commercial hunting area associated with this facility has been quarantined as well. The State Veterinarian has issued a stop-movement order for any intrastate cervid transport for 30 days in order to assess the situation.
This is the second confirmed case of CWD in Oklahoma. The first case was confirmed in a farmed elk herd in Oklahoma County in 1998. Surveillance testing around that area since then has not revealed any deer with the disease.
The Department of Agriculture, Food & Forestry and the Oklahoma Department of Wildlife Conservation are implementing emergency measures to monitor and protect the state’s wild and farmed cervid herds and will provide information to the public as it becomes available.
* * *
FOR MORE INFORMATION: Dr. Rod Hall, Oklahoma Department of Agriculture, Food & Forestry (rod.hall@ag.ok.gov); Micah Holmes, Oklahoma Department of Wildlife Conservation (micah.holmes@odwc.ok.gov)
https://www.wildlifedepartment.com/outdoor-news/chronic-wasting-disease-confirmed-one-farmed-oklahoma-elk
https://www.wildlifedepartment.com/hunting/resources/deer/cwd
Oklahoma CWD 2025
***Oklahoma CWD TSE Prion
Snip…see Full text;
Oklahoma Chronic Wasting Disease search;
October 2024 Oct 31, 2024 Cimarron County SSA Enlarged After Chronic Wasting Disease Confirmed in Dead Deer August 2023 Aug 29, 2023 Wildlife Commission Spotlights Award Winners, Gets Chronic Wasting Disease Update July 2023 Jul 3, 2023 Second CWD-positive Wild Deer Confirmed in Oklahoma June 2023 Jun 6, 2023 ODWC Activates CWD Response Strategy After Diseased Wild Deer Found in Panhandle October 2022 Oct 7, 2022 New Rules for Cimarron County Hunters October 2022 Oct 6, 2022 CWD Rules Adopted for Portions of Western Panhandle September 2022 Sep 9, 2022 ODWC Activates CWD Response Plan After Diseased Deer Found Within Miles of Panhandle November 2019 Nov 8, 2019 Conservation Partners Donate Thousands to Wildlife Commission May 2019 May 8, 2019 Commission Hears Update on CWD Status in Oklahoma May 2019 May 7, 2019 People Should Stay Away From Young Wildlife in Most Cases April 2019 Apr 24, 2019 Chronic Wasting Disease Confirmed in One Farmed Oklahoma Elk April 2019 Apr 1, 2019 Wildlife Commissioners Approve Most Rule Change Proposals January 2019 Jan 24, 2019 Wildlife Department Seeks Public Comment on CWD Rule Proposals December 2018 Dec 6, 2018 Public Comment Period Opens for Rule Change Proposals November 2018 Nov 8, 2018 Wildlife Conservation Commission Accepts NWTF, QF Donations June 2018 Jun 8, 2018 Commission Briefed on New License System Due in 2019
https://www.wildlifedepartment.com/outdoor-news
August 2025
Oklahoma Confirms Fourth Case CWD in Wild Deer
https://chronic-wasting-disease.blogspot.com/2025/08/oklahoma-confirms-fourth-case-chronic.html
Oklahoma decides to Play CWD TSE Prion Poker, and no one wins in Prion poker, with a experiment with Oklahomas wild deer herd and release GMO deer, what could go wrong, right? it’s like putting the cart before the horse science. these GMO deer are supposedly to be resistant to CWD, however, no deer has ever been confirmed to be totally resistant to CWD, and in fact, genotypes developed with very long incubation, could therefore, if released into the wild, could help spread cwd even further, exposing even more wild species, and surrounding environments, for even longer periods of time, due to the longer incubation, a terrible potential outcome, one that must be avoided at all cost, imo…terry
SCIENTISTS: RELEASING CAPTIVE-BRED DEER TO FIGHT CWD IN WILD DEER IS UNLIKELY TO WORK
October 1, 2025 By: Lindsay Thomas Jr.
Recently scientists have been exploring the idea that we can fight chronic wasting disease in wild deer by releasing captive-bred, “CWD resistant” deer. Some in the deer farming industry endorsed the idea, and legislators in Oklahoma even authorized a program to begin breeding and releasing deer. Most scientists, however, are urging everyone to pump the brakes.
On July 15, the Theodore Roosevelt Conservation Partnership invited two CWD experts to give a live webinar on the topic, titled “Breeding to Battle CWD: Can Wildlife Evolve Their Way Out of Disease?” To help shed more light on this important topic, this article is a summary of the most important take-home messages for deer hunters that came out of the two presentations. You can also watch the full presentations here.
https://www.trcp.org/chronic-wasting-disease/
PART 1: DR. DEBBIE MCKENZIE
The first speaker was Dr. Debbie McKenzie, an emeritus professor at the University of Alberta’s Centre for Prions and Protein Folding Diseases. Her research focus for the past 35 years has been on prion diseases, specifically CWD.
https://www.ualberta.ca/en/prion-centre/index.html
“Resistance” Needs More Evidence
This entire discussion originated with one study that suggested certain genetic strains of deer – known as the 96SS genotype – could be “resistant” to CWD. That study is a statistical model that suggests 96SS deer test positive for CWD less often than other deer. The study did not challenge live deer with CWD infection. Both speakers suggested they’d welcome the use of Genomically Estimated Breeding Value (GEBV) if it can slow the spread of CWD among captive herds, but they say real-world evidence is lacking so far.
“Though I think there’s some utility with GEBV, I really think we need some challenge experiments so we can demonstrate that these statistical analyses do point to increased resistance,” said Dr. McKenzie.
“Resistant” Deer Still Get CWD But Live Longer
Meanwhile, studies of actual deer, according to Dr. McKenzie, show that 96SS deer are not “resistant” but experience a longer incubation period before dying. “96SS and other polymorphisms are linked to slower disease progression, but they are not resistance genes,” she said. “If those animals are exposed, they will get CWD. It’s just going to take longer from the time they are infected until they are clinically sick.”
This chart from Dr. McKenzie’s presentation shows that some genotypes of deer survive longer than others with CWD but are not “resistant” because they can still acquire the disease. Living Longer With CWD Means Greater Spread
Longer incubation periods with CWD are counterproductive, because even CWD-infected 96SS deer are still shedding prions into the environment and sharing them with other deer. “Shedding is still occurring throughout those longer incubation periods,” said Dr. McKenzie. “If you have double the incubation period, but you’ve only made a 10% reduction in the prion shedding, you’re actually going to end up with more environmental contamination.”
New Strains Might Make “Resistant Deer” Irrelevant
New strains of CWD have already evolved, and more are coming. According to Dr. McKenzie, selecting for 96SS genetics in deer could theoretically lead to reduced susceptibility to some CWD strains. “On the other hand,” she said, “it might mean we’re selecting for susceptibility to a different strain.”
PART 2: DR. SONJA CHRISTENSEN
The second talk by Dr. Sonja Christensen took the science into the real world to look at the likelihood of using genetically resistant deer – assuming they are found to be a real thing – to fight CWD in wild deer populations. Dr. Christensen is an assistant professor at Michigan State University who specializes in wildlife disease ecology, population health, and wildlife management.
http://www.christensen-lab.org/
Wild Deer Are a Different Issue Than Captive Deer
Genetic resistance to CWD could have usefulness in captive deer, where people control which deer do the breeding. “However, I am focused solely on wild deer,” said Dr. Christensen. “Wild populations are inherently messy.”
We Can’t Manage Genetics in Wild Deer
Hunters have mistakenly believed for years that they can change the genetics of future deer through selective harvest, but repeated scientific experiments have failed to show that it’s possible to make a measurable difference – even under very intensive manipulation of deer harvest. The reasons why also explain why releasing a few “CWD resistant” deer in an area would be unlikely to have any impact on wild deer genetics.
https://deerassociation.com/strike-3-for-the-myth-of-the-genetic-cull-buck/
Dr. Christensen listed several of the factors that would complicate any kind of genetic fight against CWD in wild deer. For example, there are over 30 subspecies of whitetails with genetic variations across regions. We lack the ability to control which deer do the breeding. Any genetically modified deer released into the wild might never reproduce due to being killed by predators, other diseases, and other mortality sources beyond our control.
Existing Native Deer Prevent Success
Stocking genetically modified deer could be more successful only if native deer with higher susceptibility to CWD are first removed. Dr. Christensen pointed out that fighting scrapie, a prion disease of sheep that is similar to CWD, required massive culling of sheep to increase resistance, and this was with captive livestock. Obviously, in the wild it would be nearly impossible to identify which deer are more susceptible or remove enough of them to make a difference.
It Would Take a Very, Very Long Time
“In the best case scenario, assuming everything’s working perfectly and we can control all of these factors in a very messy, free-ranging herd, it’s still going to take years and years and years and years to really see this change and pick up on that signal,” said Dr. Christensen.
Why Not Try It Anyway?
Despite all the evidence that stocking “resistant” deer would have no impact on CWD in wild deer populations, Dr. Christensen played devil’s advocate and asked, “Why not try it anyway?” She answered by highlighting the extreme costs and the unintended consequences.
“Captive deer genetics are not like wild deer genetics,” she said. “There might be other traits that are unknowingly entering a population when you release captive deer. Something else might be expressed. Because of the long incubation period, we could unknowingly release CWD-positive deer into an area that doesn’t have the disease. We could be increasing susceptibility to other diseases.”
“The outcome has a lot of uncertainly and cost for wildlife agencies, and that’s a risk to our natural resources that the wildlife agencies are managing in the public trust,” said Dr. Christensen. “Ultimately, that is undermining the North American Model of Wildlife Management and how wildlife management works.”
Other Comments About Release of Captive-Bred Deer to Fight CWD
The CWD Research Consortium, a group of independent researchers from diverse disciplines and institutions currently working on CWD, prepared a document to provide science-based information on the use of selective breeding and release of captive deer for CWD management.
https://www.cwd-research.com/home/selective-breeding-and-release-of-captive-white
The Association of Fish & Wildlife Agencies passed a resolution opposing “the release of any captive cervids into the wild to influence free-ranging cervid population genetics for the purpose of controlling or managing CWD, based on the current best scientific information, and encourages its members in their own jurisdictions to promote and implement the best scientific management practices for CWD.”
https://www.fishwildlife.org/landing/blog/state-fish-wildlife-agency-directors-pass-ten-resolutions-afwas-2024-annual-meeting
The United States Animal Health Association issued a resolution calling on the U.S. Department of Agriculture to conduct a controlled experiment to test the validity of CWD resistant genetics.
https://usaha.org/wp-content/uploads/2024/12/2024-USAHA-Resolutions-21.pdf
Categories: Deer Science Tags: Chronic Wasting Disease, Cwd
About Lindsay Thomas Jr.: Lindsay Thomas Jr. is NDA's Chief Communications Officer. He has been a member of the staff since 2003. Prior to that, Lindsay was an editor at a Georgia hunting and fishing news magazine for nine years. Throughout his career as an editor, he has written and published numerous articles on deer management and hunting. He earned his journalism degree at the University of Georgia.
https://deerassociation.com/scientists-releasing-captive-bred-deer-to-fight-cwd-in-wild-deer-is-unlikely-to-work/
SUNDAY, MAY 04, 2025
Texas Senate Bill 2651 establishment of a pilot program to breed deer resistant to CWD TSE Prion, what could go wrong?
https://chronic-wasting-disease.blogspot.com/2025/05/texas-senate-bill-2651-establishment-of_4.html
USDA EXPLANATORY NOTES ANIMAL AND PLANT HEALTH INSPECTION SERVICE 2025-2014 CHRONIC WASTING DISEASE CWD TSE CERVID
https://chronic-wasting-disease.blogspot.com/2025/09/usda-explanatory-notes-animal-and-plant.html
Problem Statement 6B: Reveal genetics of prion disease susceptibility.
Greater frequency of chronic wasting disease in free-ranging elk genetically tolerant to disease progression raises concerns related to prion transmission and strain evolution.
Animal Disease Research Unit, Pullman, Washington
Genetic variations in the prion protein gene of Rocky Mountain elk do not confer complete resistance to fatal infection by chronic wasting disease. However, elk carrying one or two copies of the amino acid leucine (L) variant at position 132 of the prion protein (132L*, where * is either M for methionine or L) survive much longer than 132MM elk. An ARS researcher in Pullman, Washington, in collaboration with researchers at the University of Wyoming, the University of California at Davis, the National Park Service, and the Animal and Plant Health Inspection Service, found a higher frequency of 132L* elk in areas of Wyoming with high infection rates, consistent with the expected positive effect of prolonged survival on reproduction. However, the frequency of chronic wasting disease infection in 132L* elk was also higher than previous estimates. To improve the long-term management of native elk populations, these findings underscore the importance of determining the effects of prolonged infection on disease transmission from 132L* elk and the potential for driving prion strain diversification.
https://www.ars.usda.gov/ARSUserFiles/np103/AnnualReports/Final%20NP103%20FY2024%20Annual%20Report.updated%205.30.25.pdf
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
OKLAHOMA CITY — An elk from a farmed herd in Lincoln County has tested positive for chronic wasting disease (CWD), according to the Oklahoma Department of Agriculture, Food & Forestry (ODAFF) and the Oklahoma Department of Wildlife Conservation.
The 2-year-old bull elk died as the result of an injury. The elk was tested through routine surveillance in compliance with the breeding facility’s Certified Herd Plan.
CWD is a fatal neurological disease that affects the brains of elk, deer and other cervid species. No vaccine or treatment for the disease exists. Importantly, no health risk to humans or non-cervid livestock has been documented.
ODAFF has quarantined the farmed breeding facility, and the Wildlife Department will be testing wild deer in the area near the facility for the presence of CWD. The adjacent commercial hunting area associated with this facility has been quarantined as well. The State Veterinarian has issued a stop-movement order for any intrastate cervid transport for 30 days in order to assess the situation.
This is the second confirmed case of CWD in Oklahoma. The first case was confirmed in a farmed elk herd in Oklahoma County in 1998. Surveillance testing around that area since then has not revealed any deer with the disease.
The Department of Agriculture, Food & Forestry and the Oklahoma Department of Wildlife Conservation are implementing emergency measures to monitor and protect the state’s wild and farmed cervid herds and will provide information to the public as it becomes available.
* * *
FOR MORE INFORMATION: Dr. Rod Hall, Oklahoma Department of Agriculture, Food & Forestry (rod.hall@ag.ok.gov); Micah Holmes, Oklahoma Department of Wildlife Conservation (micah.holmes@odwc.ok.gov)
https://www.wildlifedepartment.com/outdoor-news/chronic-wasting-disease-confirmed-one-farmed-oklahoma-elk
https://www.wildlifedepartment.com/hunting/resources/deer/cwd
Oklahoma CWD 2025
***Oklahoma CWD TSE Prion
Snip…see Full text;
Oklahoma Chronic Wasting Disease search;
October 2024 Oct 31, 2024 Cimarron County SSA Enlarged After Chronic Wasting Disease Confirmed in Dead Deer August 2023 Aug 29, 2023 Wildlife Commission Spotlights Award Winners, Gets Chronic Wasting Disease Update July 2023 Jul 3, 2023 Second CWD-positive Wild Deer Confirmed in Oklahoma June 2023 Jun 6, 2023 ODWC Activates CWD Response Strategy After Diseased Wild Deer Found in Panhandle October 2022 Oct 7, 2022 New Rules for Cimarron County Hunters October 2022 Oct 6, 2022 CWD Rules Adopted for Portions of Western Panhandle September 2022 Sep 9, 2022 ODWC Activates CWD Response Plan After Diseased Deer Found Within Miles of Panhandle November 2019 Nov 8, 2019 Conservation Partners Donate Thousands to Wildlife Commission May 2019 May 8, 2019 Commission Hears Update on CWD Status in Oklahoma May 2019 May 7, 2019 People Should Stay Away From Young Wildlife in Most Cases April 2019 Apr 24, 2019 Chronic Wasting Disease Confirmed in One Farmed Oklahoma Elk April 2019 Apr 1, 2019 Wildlife Commissioners Approve Most Rule Change Proposals January 2019 Jan 24, 2019 Wildlife Department Seeks Public Comment on CWD Rule Proposals December 2018 Dec 6, 2018 Public Comment Period Opens for Rule Change Proposals November 2018 Nov 8, 2018 Wildlife Conservation Commission Accepts NWTF, QF Donations June 2018 Jun 8, 2018 Commission Briefed on New License System Due in 2019
https://www.wildlifedepartment.com/outdoor-news
August 2025
Oklahoma Confirms Fourth Case CWD in Wild Deer
https://chronic-wasting-disease.blogspot.com/2025/08/oklahoma-confirms-fourth-case-chronic.html
Oklahoma decides to Play CWD TSE Prion Poker, and no one wins in Prion poker, with a experiment with Oklahomas wild deer herd and release GMO deer, what could go wrong, right? it’s like putting the cart before the horse science. these GMO deer are supposedly to be resistant to CWD, however, no deer has ever been confirmed to be totally resistant to CWD, and in fact, genotypes developed with very long incubation, could therefore, if released into the wild, could help spread cwd even further, exposing even more wild species, and surrounding environments, for even longer periods of time, due to the longer incubation, a terrible potential outcome, one that must be avoided at all cost, imo…terry
SCIENTISTS: RELEASING CAPTIVE-BRED DEER TO FIGHT CWD IN WILD DEER IS UNLIKELY TO WORK
October 1, 2025 By: Lindsay Thomas Jr.
Recently scientists have been exploring the idea that we can fight chronic wasting disease in wild deer by releasing captive-bred, “CWD resistant” deer. Some in the deer farming industry endorsed the idea, and legislators in Oklahoma even authorized a program to begin breeding and releasing deer. Most scientists, however, are urging everyone to pump the brakes.
On July 15, the Theodore Roosevelt Conservation Partnership invited two CWD experts to give a live webinar on the topic, titled “Breeding to Battle CWD: Can Wildlife Evolve Their Way Out of Disease?” To help shed more light on this important topic, this article is a summary of the most important take-home messages for deer hunters that came out of the two presentations. You can also watch the full presentations here.
https://www.trcp.org/chronic-wasting-disease/
PART 1: DR. DEBBIE MCKENZIE
The first speaker was Dr. Debbie McKenzie, an emeritus professor at the University of Alberta’s Centre for Prions and Protein Folding Diseases. Her research focus for the past 35 years has been on prion diseases, specifically CWD.
https://www.ualberta.ca/en/prion-centre/index.html
“Resistance” Needs More Evidence
This entire discussion originated with one study that suggested certain genetic strains of deer – known as the 96SS genotype – could be “resistant” to CWD. That study is a statistical model that suggests 96SS deer test positive for CWD less often than other deer. The study did not challenge live deer with CWD infection. Both speakers suggested they’d welcome the use of Genomically Estimated Breeding Value (GEBV) if it can slow the spread of CWD among captive herds, but they say real-world evidence is lacking so far.
“Though I think there’s some utility with GEBV, I really think we need some challenge experiments so we can demonstrate that these statistical analyses do point to increased resistance,” said Dr. McKenzie.
“Resistant” Deer Still Get CWD But Live Longer
Meanwhile, studies of actual deer, according to Dr. McKenzie, show that 96SS deer are not “resistant” but experience a longer incubation period before dying. “96SS and other polymorphisms are linked to slower disease progression, but they are not resistance genes,” she said. “If those animals are exposed, they will get CWD. It’s just going to take longer from the time they are infected until they are clinically sick.”
This chart from Dr. McKenzie’s presentation shows that some genotypes of deer survive longer than others with CWD but are not “resistant” because they can still acquire the disease. Living Longer With CWD Means Greater Spread
Longer incubation periods with CWD are counterproductive, because even CWD-infected 96SS deer are still shedding prions into the environment and sharing them with other deer. “Shedding is still occurring throughout those longer incubation periods,” said Dr. McKenzie. “If you have double the incubation period, but you’ve only made a 10% reduction in the prion shedding, you’re actually going to end up with more environmental contamination.”
New Strains Might Make “Resistant Deer” Irrelevant
New strains of CWD have already evolved, and more are coming. According to Dr. McKenzie, selecting for 96SS genetics in deer could theoretically lead to reduced susceptibility to some CWD strains. “On the other hand,” she said, “it might mean we’re selecting for susceptibility to a different strain.”
PART 2: DR. SONJA CHRISTENSEN
The second talk by Dr. Sonja Christensen took the science into the real world to look at the likelihood of using genetically resistant deer – assuming they are found to be a real thing – to fight CWD in wild deer populations. Dr. Christensen is an assistant professor at Michigan State University who specializes in wildlife disease ecology, population health, and wildlife management.
http://www.christensen-lab.org/
Wild Deer Are a Different Issue Than Captive Deer
Genetic resistance to CWD could have usefulness in captive deer, where people control which deer do the breeding. “However, I am focused solely on wild deer,” said Dr. Christensen. “Wild populations are inherently messy.”
We Can’t Manage Genetics in Wild Deer
Hunters have mistakenly believed for years that they can change the genetics of future deer through selective harvest, but repeated scientific experiments have failed to show that it’s possible to make a measurable difference – even under very intensive manipulation of deer harvest. The reasons why also explain why releasing a few “CWD resistant” deer in an area would be unlikely to have any impact on wild deer genetics.
https://deerassociation.com/strike-3-for-the-myth-of-the-genetic-cull-buck/
Dr. Christensen listed several of the factors that would complicate any kind of genetic fight against CWD in wild deer. For example, there are over 30 subspecies of whitetails with genetic variations across regions. We lack the ability to control which deer do the breeding. Any genetically modified deer released into the wild might never reproduce due to being killed by predators, other diseases, and other mortality sources beyond our control.
Existing Native Deer Prevent Success
Stocking genetically modified deer could be more successful only if native deer with higher susceptibility to CWD are first removed. Dr. Christensen pointed out that fighting scrapie, a prion disease of sheep that is similar to CWD, required massive culling of sheep to increase resistance, and this was with captive livestock. Obviously, in the wild it would be nearly impossible to identify which deer are more susceptible or remove enough of them to make a difference.
It Would Take a Very, Very Long Time
“In the best case scenario, assuming everything’s working perfectly and we can control all of these factors in a very messy, free-ranging herd, it’s still going to take years and years and years and years to really see this change and pick up on that signal,” said Dr. Christensen.
Why Not Try It Anyway?
Despite all the evidence that stocking “resistant” deer would have no impact on CWD in wild deer populations, Dr. Christensen played devil’s advocate and asked, “Why not try it anyway?” She answered by highlighting the extreme costs and the unintended consequences.
“Captive deer genetics are not like wild deer genetics,” she said. “There might be other traits that are unknowingly entering a population when you release captive deer. Something else might be expressed. Because of the long incubation period, we could unknowingly release CWD-positive deer into an area that doesn’t have the disease. We could be increasing susceptibility to other diseases.”
“The outcome has a lot of uncertainly and cost for wildlife agencies, and that’s a risk to our natural resources that the wildlife agencies are managing in the public trust,” said Dr. Christensen. “Ultimately, that is undermining the North American Model of Wildlife Management and how wildlife management works.”
Other Comments About Release of Captive-Bred Deer to Fight CWD
The CWD Research Consortium, a group of independent researchers from diverse disciplines and institutions currently working on CWD, prepared a document to provide science-based information on the use of selective breeding and release of captive deer for CWD management.
https://www.cwd-research.com/home/selective-breeding-and-release-of-captive-white
The Association of Fish & Wildlife Agencies passed a resolution opposing “the release of any captive cervids into the wild to influence free-ranging cervid population genetics for the purpose of controlling or managing CWD, based on the current best scientific information, and encourages its members in their own jurisdictions to promote and implement the best scientific management practices for CWD.”
https://www.fishwildlife.org/landing/blog/state-fish-wildlife-agency-directors-pass-ten-resolutions-afwas-2024-annual-meeting
The United States Animal Health Association issued a resolution calling on the U.S. Department of Agriculture to conduct a controlled experiment to test the validity of CWD resistant genetics.
https://usaha.org/wp-content/uploads/2024/12/2024-USAHA-Resolutions-21.pdf
Categories: Deer Science Tags: Chronic Wasting Disease, Cwd
About Lindsay Thomas Jr.: Lindsay Thomas Jr. is NDA's Chief Communications Officer. He has been a member of the staff since 2003. Prior to that, Lindsay was an editor at a Georgia hunting and fishing news magazine for nine years. Throughout his career as an editor, he has written and published numerous articles on deer management and hunting. He earned his journalism degree at the University of Georgia.
https://deerassociation.com/scientists-releasing-captive-bred-deer-to-fight-cwd-in-wild-deer-is-unlikely-to-work/
SUNDAY, MAY 04, 2025
Texas Senate Bill 2651 establishment of a pilot program to breed deer resistant to CWD TSE Prion, what could go wrong?
https://chronic-wasting-disease.blogspot.com/2025/05/texas-senate-bill-2651-establishment-of_4.html
USDA EXPLANATORY NOTES ANIMAL AND PLANT HEALTH INSPECTION SERVICE 2025-2014 CHRONIC WASTING DISEASE CWD TSE CERVID
https://chronic-wasting-disease.blogspot.com/2025/09/usda-explanatory-notes-animal-and-plant.html
Problem Statement 6B: Reveal genetics of prion disease susceptibility.
Greater frequency of chronic wasting disease in free-ranging elk genetically tolerant to disease progression raises concerns related to prion transmission and strain evolution.
Animal Disease Research Unit, Pullman, Washington
Genetic variations in the prion protein gene of Rocky Mountain elk do not confer complete resistance to fatal infection by chronic wasting disease. However, elk carrying one or two copies of the amino acid leucine (L) variant at position 132 of the prion protein (132L*, where * is either M for methionine or L) survive much longer than 132MM elk. An ARS researcher in Pullman, Washington, in collaboration with researchers at the University of Wyoming, the University of California at Davis, the National Park Service, and the Animal and Plant Health Inspection Service, found a higher frequency of 132L* elk in areas of Wyoming with high infection rates, consistent with the expected positive effect of prolonged survival on reproduction. However, the frequency of chronic wasting disease infection in 132L* elk was also higher than previous estimates. To improve the long-term management of native elk populations, these findings underscore the importance of determining the effects of prolonged infection on disease transmission from 132L* elk and the potential for driving prion strain diversification.
https://www.ars.usda.gov/ARSUserFiles/np103/AnnualReports/Final%20NP103%20FY2024%20Annual%20Report.updated%205.30.25.pdf
Research Project: Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies
Location: Virus and Prion Research
Title: Update: CWD genetic resistance project at NADC
Author item Cassmann, Eric item Greenlee, Justin Submitted to: North American Deer Farmer Publication Type: Trade Journal Publication Acceptance Date: 11/5/2023 Publication Date: 11/15/2023 Citation: Cassmann, E.D., Greenlee, J.J. 2023.
Update: CWD genetic resistance project at NADC. North American Deer Farmer. P. 83. Interpretive Summary: Technical Abstract: In March of 2020, we began a study to examine the susceptibility of whitetail deer with rare prion protein genotypes to chronic wasting disease (CWD). In the sequence of amino acids that make up the deer prion protein, there are several locations that are variable. These variations are sometimes called polymorphisms. In the data collected from depopulations, whitetail deer with certain prion gene polymorphisms were not positive for CWD. In 2019, Dr. Nick Haley published a paper that showed H95/S96, HH95, and S96/K226 deer from depopulated herds in the US were not CWD positive. Based on the overall low number of deer with these genotypes () we’re unable to determine if they were resistant to CWD or if there were too few deer with these genotypes to be statistically represented in the positive cases. It’s also possible that they could be partially susceptible with longer incubation times than deer with generic (wild type) prion genotypes. Samples gathered at depopulation represent a snapshot of the herd. It is possible these rare genotypes were exposed, but had not yet accumulated abnormal prion protein to a level detectable by the detection methods used. The NADC susceptibility study was initiated to help answer these questions.
We studied deer with polymorphisms at 3 amino acid locations (codons): 95, 96, and 226. Wild type deer are QQ95GG96QQ226. Whitetail deer with wild type prion genotypes were inoculated with CWD and co-housed with other whitetail deer (contact deer) that had rare prion protein genotypes. The genotypes of contact deer included QH95GS96QQ226, QH95GG96QK226, QQ95GS96QQ226, QQ95SS96QQ226, Q95GS96QK226, and QQ95GG96KK226 (bolded text indicates a prion gene polymorphism).
During the first year, we collected feces, saliva, nasal swabs, skin, blood, and rectal biopsies from the inoculated and contact deer to determine if deer are CWD positive and the period of CWD shedding. After the first year, we started collecting rectal biopsies annually on the contact deer, but all other samples are still collected every three months.
Eight out of ten (8/10) inoculated deer developed clinical signs for CWD and tested positive after necropsy (Figure 1). The average time from inoculation to euthanasia of these eight inoculated deer was 23 months.
Two inoculated deer are still on-study; one of these deer has tested positive for CWD on rectal biopsy IHC.
To date, two deer from the contact group have developed CWD clinical signs and tested positive (Figure 2). The positive deer from the contact group had the GS96QK226 and KK226 genotypes.
We have detected CWD prions in rectal biopsies with IHC in three other contact deer as of October 2023. Their prion genotypes are GS96, QH95GS96, and GS96QK226.
As the experiment continues, we hope to answer 2 main questions. (1) Are there any prion protein polymorphisms that make deer resistant to CWD, and (2) what are the CWD shedding dynamics in deer with detectable CWD. One potential outcome of the study would be identifying genotypes with very long incubation periods that, while susceptible to CWD, still could be used to manage CWD.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=410188
Update: CWD genetic resistance project at NADC 1) Are there any prion protein polymorphisms that make deer resistant to CWD, and (2) what are the CWD shedding dynamics in deer with detectable CWD. One potential outcome of the study would be identifying genotypes with very long incubation periods that, while susceptible to CWD, still could be used to manage CWD.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=410188
Another potential and likely outcome of this study, imo, is that genotypes developed with very long incubation, could therefore, if released into the wild, could help spread cwd even further, exposing even more wild species, and surrounding environments, for even longer periods of time, due to the longer incubation, a terrible potential outcome, one that must be avoided at all cost, imo…terry
SUNDAY, MAY 04, 2025
Texas Senate Bill 2651 establishment of a pilot program to breed deer resistant to CWD TSE Prion, what could go wrong?
https://chronic-wasting-disease.blogspot.com/2025/05/texas-senate-bill-2651-establishment-of_4.html
FRIDAY, FEBRUARY 21, 2025
LEGISLATING CWD TSE Prion, Bills to release Genetically Modified Cervid into the wild, what could go wrong?
https://chronic-wasting-disease.blogspot.com/2025/02/legislating-cwd-tse-prion-bills-to.html
MONDAY, JUNE 09, 2025
Genetic Approaches and Tools to Prevent, Control, and Eradicate Transmissible Spongiform Encephalopathies 2024 Annual Report ARS Research
https://chronic-wasting-disease.blogspot.com/2025/06/genetic-approaches-and-tools-to-prevent.html
Oklahoma HB3462 Chronic Wasting Disease Genetic Improvement Act and Legislating CWD Science
Bill Summary 2nd Session of the 59th Legislature Bill No.: HB 3462 Version: CS Request No.: 3679 Author: Sen. Green Date: 04/08/2024 Bill Analysis
Greetings to the Great State of Oklahoma!
I must comment on the following please!
HB 3462 creates the Chronic Wasting Disease Genetic Improvement Act. The measure directs the Oklahoma Department of Agriculture, Food, and Forestry to establish a pilot program to enhance the genetic durability of Oklahoma deer against chronic wasting disease no later than November 1, 2024. The program shall require the Department of Wildlife Conservation to collect DNA samples to establish a baseline of average genetic codon markers and genomic breeding values. Participation in the program shall be limited to native white-tailed deer, born and raised in Oklahoma with genetic resistance breeding. Bred deer may be released in 2026, during the months of February and March and through the 15th of April. The Department of Wildlife Conservation may charge a one-time permit fee for citizens purchasing deer. The fee shall not exceed $500.00.
Prepared by: Kalen Taylor
http://webserver1.lsb.state.ok.us/cf_pdf/2023-24%20SUPPORT%20DOCUMENTS/BILLSUM/Senate/HB3462%20CS%20BILLSUM.PDF
Snip…see;
https://chronic-wasting-disease.blogspot.com/2024/05/oklahoma-hb3462-chronic-wasting-disease.html
USDA EXPLANATORY NOTES ANIMAL AND PLANT HEALTH INSPECTION SERVICE 2025-2014 CHRONIC WASTING DISEASE CWD TSE CERVID
https://chronic-wasting-disease.blogspot.com/2025/09/usda-explanatory-notes-animal-and-plant.html
SUNDAY, MARCH 8, 2026
Texas Creutzfeldt-Jakob Disease Deaths and Death Rates per Year (2013-2022) More Than Tripled, and case reporting has ceased since then
https://cjdtexas.blogspot.com/2026/03/texas-creutzfeldt-jakob-disease-deaths.html
https://prpsc.proboards.com/thread/209/texas-cases-more-triples-2013
WEDNESDAY, OCTOBER 15, 2025
US NATIONAL PRION DISEASE PATHOLOGY SURVEILLANCE CENTER CJD TSE REPORT 2025
https://prionunitusaupdate.blogspot.com/2025/10/us-national-prion-disease-pathology.html
FRIDAY, NOVEMBER 21, 2025
While no one was watching: Tenuous status of CDC prion unit, risk of CWD to people worry scientists
https://chronic-wasting-disease.blogspot.com/2025/11/while-no-one-was-watching-tenuous.html
SATURDAY, JANUARY 10, 2026
Neuropsychiatric symptoms in sporadic Creutzfeldt-Jakob disease, a review
https://creutzfeldt-jakob-disease.blogspot.com/2026/01/neuropsychiatric-symptoms-in-sporadic.html
https://prpsc.proboards.com/thread/191/neuropsychiatric-symptoms-sporadic-cjd-review
SUNDAY, MARCH 23, 2025
Creutzfeldt Jakob Disease TSE Prion Increasing 2025 Update
https://creutzfeldt-jakob-disease.blogspot.com/2025/03/creutzfeldt-jakob-disease-tse-prion.html
FRIDAY, DECEMBER 13, 2024
Creutzfeldt Jacob Disease CJD, BSE, CWD, TSE Prion, December 14, 2024 Annual Update
https://creutzfeldt-jakob-disease.blogspot.com/2024/12/creutzfeldt-jacob-disease-cjd-bse-cwd.html
Terry S. Singeltary Sr. Bacliff, Texas 77518 flounder9@verizon.net
Update: CWD genetic resistance project at NADC. North American Deer Farmer. P. 83. Interpretive Summary: Technical Abstract: In March of 2020, we began a study to examine the susceptibility of whitetail deer with rare prion protein genotypes to chronic wasting disease (CWD). In the sequence of amino acids that make up the deer prion protein, there are several locations that are variable. These variations are sometimes called polymorphisms. In the data collected from depopulations, whitetail deer with certain prion gene polymorphisms were not positive for CWD. In 2019, Dr. Nick Haley published a paper that showed H95/S96, HH95, and S96/K226 deer from depopulated herds in the US were not CWD positive. Based on the overall low number of deer with these genotypes () we’re unable to determine if they were resistant to CWD or if there were too few deer with these genotypes to be statistically represented in the positive cases. It’s also possible that they could be partially susceptible with longer incubation times than deer with generic (wild type) prion genotypes. Samples gathered at depopulation represent a snapshot of the herd. It is possible these rare genotypes were exposed, but had not yet accumulated abnormal prion protein to a level detectable by the detection methods used. The NADC susceptibility study was initiated to help answer these questions.
We studied deer with polymorphisms at 3 amino acid locations (codons): 95, 96, and 226. Wild type deer are QQ95GG96QQ226. Whitetail deer with wild type prion genotypes were inoculated with CWD and co-housed with other whitetail deer (contact deer) that had rare prion protein genotypes. The genotypes of contact deer included QH95GS96QQ226, QH95GG96QK226, QQ95GS96QQ226, QQ95SS96QQ226, Q95GS96QK226, and QQ95GG96KK226 (bolded text indicates a prion gene polymorphism).
During the first year, we collected feces, saliva, nasal swabs, skin, blood, and rectal biopsies from the inoculated and contact deer to determine if deer are CWD positive and the period of CWD shedding. After the first year, we started collecting rectal biopsies annually on the contact deer, but all other samples are still collected every three months.
Eight out of ten (8/10) inoculated deer developed clinical signs for CWD and tested positive after necropsy (Figure 1). The average time from inoculation to euthanasia of these eight inoculated deer was 23 months.
Two inoculated deer are still on-study; one of these deer has tested positive for CWD on rectal biopsy IHC.
To date, two deer from the contact group have developed CWD clinical signs and tested positive (Figure 2). The positive deer from the contact group had the GS96QK226 and KK226 genotypes.
We have detected CWD prions in rectal biopsies with IHC in three other contact deer as of October 2023. Their prion genotypes are GS96, QH95GS96, and GS96QK226.
As the experiment continues, we hope to answer 2 main questions. (1) Are there any prion protein polymorphisms that make deer resistant to CWD, and (2) what are the CWD shedding dynamics in deer with detectable CWD. One potential outcome of the study would be identifying genotypes with very long incubation periods that, while susceptible to CWD, still could be used to manage CWD.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=410188
Update: CWD genetic resistance project at NADC 1) Are there any prion protein polymorphisms that make deer resistant to CWD, and (2) what are the CWD shedding dynamics in deer with detectable CWD. One potential outcome of the study would be identifying genotypes with very long incubation periods that, while susceptible to CWD, still could be used to manage CWD.
https://www.ars.usda.gov/research/publications/publication/?seqNo115=410188
Another potential and likely outcome of this study, imo, is that genotypes developed with very long incubation, could therefore, if released into the wild, could help spread cwd even further, exposing even more wild species, and surrounding environments, for even longer periods of time, due to the longer incubation, a terrible potential outcome, one that must be avoided at all cost, imo…terry
SUNDAY, MAY 04, 2025
Texas Senate Bill 2651 establishment of a pilot program to breed deer resistant to CWD TSE Prion, what could go wrong?
https://chronic-wasting-disease.blogspot.com/2025/05/texas-senate-bill-2651-establishment-of_4.html
FRIDAY, FEBRUARY 21, 2025
LEGISLATING CWD TSE Prion, Bills to release Genetically Modified Cervid into the wild, what could go wrong?
https://chronic-wasting-disease.blogspot.com/2025/02/legislating-cwd-tse-prion-bills-to.html
MONDAY, JUNE 09, 2025
Genetic Approaches and Tools to Prevent, Control, and Eradicate Transmissible Spongiform Encephalopathies 2024 Annual Report ARS Research
https://chronic-wasting-disease.blogspot.com/2025/06/genetic-approaches-and-tools-to-prevent.html
Oklahoma HB3462 Chronic Wasting Disease Genetic Improvement Act and Legislating CWD Science
Bill Summary 2nd Session of the 59th Legislature Bill No.: HB 3462 Version: CS Request No.: 3679 Author: Sen. Green Date: 04/08/2024 Bill Analysis
Greetings to the Great State of Oklahoma!
I must comment on the following please!
HB 3462 creates the Chronic Wasting Disease Genetic Improvement Act. The measure directs the Oklahoma Department of Agriculture, Food, and Forestry to establish a pilot program to enhance the genetic durability of Oklahoma deer against chronic wasting disease no later than November 1, 2024. The program shall require the Department of Wildlife Conservation to collect DNA samples to establish a baseline of average genetic codon markers and genomic breeding values. Participation in the program shall be limited to native white-tailed deer, born and raised in Oklahoma with genetic resistance breeding. Bred deer may be released in 2026, during the months of February and March and through the 15th of April. The Department of Wildlife Conservation may charge a one-time permit fee for citizens purchasing deer. The fee shall not exceed $500.00.
Prepared by: Kalen Taylor
http://webserver1.lsb.state.ok.us/cf_pdf/2023-24%20SUPPORT%20DOCUMENTS/BILLSUM/Senate/HB3462%20CS%20BILLSUM.PDF
Snip…see;
https://chronic-wasting-disease.blogspot.com/2024/05/oklahoma-hb3462-chronic-wasting-disease.html
USDA EXPLANATORY NOTES ANIMAL AND PLANT HEALTH INSPECTION SERVICE 2025-2014 CHRONIC WASTING DISEASE CWD TSE CERVID
https://chronic-wasting-disease.blogspot.com/2025/09/usda-explanatory-notes-animal-and-plant.html
SUNDAY, MARCH 8, 2026
Texas Creutzfeldt-Jakob Disease Deaths and Death Rates per Year (2013-2022) More Than Tripled, and case reporting has ceased since then
https://cjdtexas.blogspot.com/2026/03/texas-creutzfeldt-jakob-disease-deaths.html
https://prpsc.proboards.com/thread/209/texas-cases-more-triples-2013
WEDNESDAY, OCTOBER 15, 2025
US NATIONAL PRION DISEASE PATHOLOGY SURVEILLANCE CENTER CJD TSE REPORT 2025
https://prionunitusaupdate.blogspot.com/2025/10/us-national-prion-disease-pathology.html
FRIDAY, NOVEMBER 21, 2025
While no one was watching: Tenuous status of CDC prion unit, risk of CWD to people worry scientists
https://chronic-wasting-disease.blogspot.com/2025/11/while-no-one-was-watching-tenuous.html
SATURDAY, JANUARY 10, 2026
Neuropsychiatric symptoms in sporadic Creutzfeldt-Jakob disease, a review
https://creutzfeldt-jakob-disease.blogspot.com/2026/01/neuropsychiatric-symptoms-in-sporadic.html
https://prpsc.proboards.com/thread/191/neuropsychiatric-symptoms-sporadic-cjd-review
SUNDAY, MARCH 23, 2025
Creutzfeldt Jakob Disease TSE Prion Increasing 2025 Update
https://creutzfeldt-jakob-disease.blogspot.com/2025/03/creutzfeldt-jakob-disease-tse-prion.html
FRIDAY, DECEMBER 13, 2024
Creutzfeldt Jacob Disease CJD, BSE, CWD, TSE Prion, December 14, 2024 Annual Update
https://creutzfeldt-jakob-disease.blogspot.com/2024/12/creutzfeldt-jacob-disease-cjd-bse-cwd.html
Terry S. Singeltary Sr. Bacliff, Texas 77518 flounder9@verizon.net
posted by Terry S. Singeltary Sr. at
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