Chronic Wasting Disease: 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) 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???

Shedding, retention and spreading of chronic wasting disease prions in the environment

Project Number 2R01AI132695-06A1 Former Number 2R01AI132695-06 Contact PI/Project Leader MORALES, RODRIGO

Abstract Text

ABSTRACT

Chronic Wasting Disease (CWD) is a prion disease affecting natural and captive cervid populations. This disease is progressively spreading across the United States and new foci of infectivity are constantly being reported. Despite decades of research, there are still several unanswered questions concerning CWD.

Compelling evidence suggest that CWD prions enter the environment through carcasses from diseased animals or by the progressive accumulation of prions shed in excreta. Unfortunately, the role that plants, parasites, predators, and scavengers play in CWD spreading has been poorly studied. During the past funding cycle, our group made important technical and conceptual contributions in this field.

Data from our group and others (in collaboration) demonstrate that plants can bind prions into their surfaces as well as transport them from soils to leaves. This is relevant, considering that prions are shown to progressively accumulate in soils and strongly suggests plants as potential vectors for CWD transmission. Unfortunately, the previously mentioned evidence has been collected using proof-of-concept conditions, including the exposure of high titers of rodent (laboratory generated) adapted prions, and grass plants only.

We have generated preliminary data showing that carrots grown in CWD infected soil carry prions in their roots and leaves as evaluated by bioassays. In contrast, tomato plants do not share these features. The significance of these findings cannot be ignored considering the interaction of CWD prions with a human and animal edible vegetable. Considering the use of carrots roots and leaves in human and animal nutrition, and the still unknown zoonotic potential of CWD, future research involving edible plants is urgently needed.

Another relevant (published) finding from our laboratory involves the high CWD infectivity titers found in nasal bots, a common cervid parasite that develops in the nasal cavity (a hotspot of prion infectivity). These parasites are found in large quantities in CWD pre- clinical and clinical deer, and may importantly contribute to environmental CWD transmission. Our research also identified CWD prions in naturally exposed flies, ticks, and dermestid beetles. However, the prion infectivity titers in these parasites have not been evaluated.

Finally, animals other than cervids, including hunters and scavengers, are expected to be exposed to CWD prions. Interestingly, we identified CWD prions and de novo generated porcine prions in tissues from wild pigs living in areas with variable CWD epidemiology. We plan to further investigate all these events and their relevance in natural prion transmission using a complementary set of techniques, including in vitro and in vivo systems. Emphasis will be made in analyzing the strain properties and zoonotic potentials of the prion agents under investigation. For this purpose, we gathered a unique group of collaborators able to supply us with the samples and expertise required to execute this project. Outcomes from this research are expected to deliver new insights on this animal prionopathy and provide regulatory agencies with useful information to control its continuous spread.

Public Health Relevance Statement

PROJECT NARRATIVE Despite decades of research, several questions remain unanswered for the Chronic Wasting Disease (CWD) epidemic affecting several deer species in the United States. Continuing with our previous R01 project, we will explore novel factors mediating the spread of CWD prions, including different plant types, invertebrate parasites (e.g., ticks, nasal bots) and scavengers (wild boars). These potential disease vectors will be studied for their ability to transmit disease within and across species, including humans.

https://reporter.nih.gov/search/VYlhnadNtUiur19eYeRPog/project-details/11227445#description

Infectious prions in brains and muscles of domestic pigs experimentally challenged with the BSE, scrapie, and CWD agents

Authors: Francisca Bravo-Risi, Fraser Brydon, Angela Chong, Kane Spicker, Justin J. Greenlee https://orcid.org/0000-0003-2202-3054, Glenn Telling, Claudio Soto https://orcid.org/0000-0002-3412-0524, Sandra Pritzkow, Marcelo A. Barria, Rodrigo Morales

ABSTRACT

Experimental studies suggest that animal species not previously described as naturally infected by prions are susceptible to prion diseases affecting sheep, cattle, and deer. These interspecies transmissions may generate prions with unknown host ranges. Pigs are susceptible to prions from different origins, including deer chronic wasting disease (CWD), sheep scrapie, and bovine spongiform encephalopathy (BSE). Here, we studied prions in brains and muscles from pigs previously infected with these different prion sources. Specifically, we measured the total prion protein (PrP) and PK-resistant PrP by western blot. Seeding activity in these tissues was evaluated using the protein misfolding cyclic amplification (PMCA) technique. We found that BSE-infected pigs contained substantially more seeding competent prions compared with those infected with CWD and scrapie. Moreover, the zoonotic potential of porcine-BSE prions seems to be relevant, as both brains and muscles from BSE-infected pigs induced the misfolding of the human prion protein in vitro. This study helps to understand the potential fate of naturally existing prion strains in a relevant host and calls for caution considering the co-existence between feral swine and other prion-susceptible animal species.

IMPORTANCE

Prions (PrPSc) are proteinaceous, infectious pathogens responsible for prion diseases. Some livestock are highly susceptible to prion diseases. These include cattle (bovine spongiform encephalopathy, BSE), sheep and goat (scrapie), and cervids (chronic wasting disease, CWD). Unfortunately, BSE has been reported to be naturally transmitted to humans and other animal species. Domestic pigs, a relevant livestock animal, have not been reported to be naturally affected by prions; however, they are susceptible to the experimental exposure to BSE, scrapie, and CWD prions. Given the widespread consumption of porcine food products by humans, we aimed to evaluate the levels of pig-derived BSE, scrapie, and CWD prions from experimentally challenged domestic pigs in brain and meat cuts (leg, cheek meat, skirt meat, and tenderloin). We detected pig-adapted prions in the brains and some muscles of these animals. Additionally, we evaluated the in vitro compatibility between pig prions and the human prion protein (as a surrogate of zoonosis). Our results show that only pig-derived BSE prions were able to induce the misfolding of the cellular human prion protein. This data highlights the consequences of prion spillovers to other animal species and their potential availability to humans.

Snip…

In summary, our data shows the dynamic of animal prions when exposed to infectious pigs, as well as their distributions and zoonotic potentials. The data presented here may be relevant to understanding the fate of naturally existing prions in a sympatric animal species relevant for human consumption. This acquires importance considering a recent report describing the interaction between CWD and wild pigs in natural settings.

https://journals.asm.org/doi/10.1128/mbio.01800-25

Volume 31, Number 1—January 2025

Dispatch

Detection of Prions in Wild Pigs (Sus scrofa) from Areas with Reported Chronic Wasting Disease Cases, United States

Paulina Soto, Francisca Bravo-Risi, Rebeca Benavente, Tucker H. Stimming, Michael J. Bodenchuk, Patrick Whitley, Clint Turnage, Terry R. Spraker, Justin Greenlee, Glenn Telling, Jennifer Malmberg, Thomas Gidlewski, Tracy Nichols, Vienna R. Brown, and Rodrigo Morales Author affiliation: The University of Texas Health Science Center at Houston, Texas, USA (P. Soto, F. Bravo-Risi, R. Benavente, T.H. Stimming, R. Morales); Centro Integrativo de Biologia y Quimica Aplicada, Universidad Bernardo O’Higgins, Santiago, Chile (P. Soto, F. Bravo-Risi, R. Morales); US Department of Agriculture, Fort Collins, Colorado, USA (M.J. Bodenchuk, P. Whitley, C. Turnage, J. Malmberg, T. Gidlewski, T. Nichols, V.R. Brown); Colorado State University, Fort Collins, Colorado, USA (T.R. Spraker, G. Telling); US Department of Agriculture, Ames, Iowa, USA (J. Greenlee)

Abstract

Using a prion amplification assay, we identified prions in tissues from wild pigs (Sus scrofa) living in areas of the United States with variable chronic wasting disease (CWD) epidemiology. Our findings indicate that scavenging swine could play a role in disseminating CWD and could therefore influence its epidemiology, geographic distribution, and interspecies spread.

Chronic wasting disease (CWD) is a prion disease of particular concern because of its uncontrolled contagious spread among various cervid species in North America https://www.usgs.gov/media/images/distribution-chronic-wasting-disease-north-america
its recent discovery in Nordic countries (1), and its increasingly uncertain zoonotic potential (2). CWD is the only animal prion disease affecting captive as well as wild animals. Persistent shedding of prions by CWD-affected animals and resulting environmental contamination is considered a major route of transmission contributing to spread of the disease. Carcasses of CWD-affected animals represent relevant sources of prion infectivity to multiple animal species that can develop disease or act as vectors to spread infection to new locations.

Free-ranging deer are sympatric with multiple animal species, including some that act as predators, scavengers, or both. Experimental transmissions to study the potential for interspecies CWD transmissions have been attempted in raccoons, ferrets, cattle, sheep, and North American rodents (3–7). Potential interspecies CWD transmission has also been addressed using transgenic (Tg) mice expressing prion proteins (PrP) from relevant animal species (8). Although no reports of natural interspecies CWD transmissions have been documented, experimental studies strongly suggest the possibility for interspecies transmission in nature exists (3–7). Inoculation and serial passage studies reveal the potential of CWD prions to adapt to noncervid species, resulting in emergence of novel prion strains with unpredicted features (9–11).

Wild pigs (Sus scrofa), also called feral swine, are an invasive population comprising domestic swine, Eurasian wild boar, and hybrids of the 2 species (12). Wild pig populations have become established in the United States (Appendix Figure 1, panel A), enabled by their high rates of fecundity; omnivorous and opportunistic diet; and widespread, often human-mediated movement (13). Wild pigs scavenge carcasses on the landscape and have an intimate relationship with the soil because of their routine rooting and wallowing behaviors (14). CWD prions have been experimentally transmitted to domestic pigs by intracerebral and oral exposure routes (15), which is relevant because wild pigs coexist with cervids in CWD endemic areas and reportedly prey on fawns and scavenge deer carcasses. Considering the species overlap in many parts of the United States (Appendix Figure 1, panel B), we studied potential interactions between wild pigs and CWD prions.

Snip…

Conclusions

In summary, results from this study showed that wild pigs are exposed to cervid prions, although the pigs seem to display some resistance to infection via natural exposure. Future studies should address the susceptibility of this invasive animal species to the multiple prion strains circulating in the environment. Nonetheless, identification of CWD prions in wild pig tissues indicated the potential for pigs to move prions across the landscape, which may, in turn, influence the epidemiology and geographic spread of CWD.

https://wwwnc.cdc.gov/eid/article/31/1/24-0401_article

Title: Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease

Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains…

https://www.ars.usda.gov/research/publications/publication/?seqNo115=337105

CWD TSE Prion, Pigs, Transmission, Livestock, Humans, what if?

CONFIDENTIAL

EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY

While this clearly is a cause for concern we should not jump to the conclusion that this means that pigs will necessarily be infected by bone and meat meal fed by the oral route as is the case with cattle…

http://web.archive.org/web/20031026000118/www.bseinquiry.gov.uk/files/yb/1990/08/23004001.pdf

we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action…

http://web.archive.org/web/20030822031154/www.bseinquiry.gov.uk/files/yb/1990/09/10007001.pdf

May I, at the outset, reiterate that we should avoid dissemination of papers relating to this experimental finding to prevent premature release of the information…

http://web.archive.org/web/20030822052332/www.bseinquiry.gov.uk/files/yb/1990/09/11005001.pdf

3. It is particularly important that this information is not passed outside the Department, until Ministers have decided how they wish it to be handled…

http://web.archive.org/web/20030822052438/www.bseinquiry.gov.uk/files/yb/1990/09/12002001.pdf

But it would be easier for us if pharmaceuticals/devices are not directly mentioned at all…

http://web.archive.org/web/20030518170213/www.bseinquiry.gov.uk/files/yb/1990/09/13004001.pdf

Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom...

http://web.archive.org/web/20030822054419/www.bseinquiry.gov.uk/files/yb/1990/09/21009001.pdf

It was not until . . . August 1990, that the result from the pig persuaded both SEAC and us to change our view and to take out of pig rations any residual infectivity that might have arisen from the SBOs.

http://web.archive.org/web/20071014143511/http://www.bseinquiry.gov.uk/files/tr/tab69.pdf

4.303 The minutes of the meeting record that:

It was very difficult to draw conclusions from one experimental result for what may happen in the field. However it would be prudent to exclude specified bovine offals from the pig diet. Although any relationship between BSE and the finding of a spongiform encephalopathy in cats had yet to be demonstrated, the fact that this had occurred suggested that a cautious view should be taken of those species which might be susceptible. The 'specified offals' of bovines should therefore be excluded from the feed of all species. 17

http://web.archive.org/web/20031026084516/http://www.bseinquiry.gov.uk/files/yb/1990/09/07001001.pdf

IN CONFIENCE

EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY

1. CMO should be aware that a pig inoculated experimentally (ic, iv, and ip) with BSE brain suspension has after 15 months developed an illness, now confirmed as a spongiform encephalopathy. This is the first ever description of such a disease in a pig, although it seems there ar no previous attempts at experimental inoculation with animal material. The Southwood group had thought igs would not be susceptible. Most pigs are slaughtered when a few weeks old but there have been no reports of relevant neurological illness in breeding sows or other elderly pigs. ...see full text ;

http://web.archive.org/web/20040302031004/www.bseinquiry.gov.uk/files/yb/1990/08/23001001.pdf

IN CONFIDENCE

So it is plausible pigs could be preclinically affected with BSE but since so few are allowed to reach adulthood this has not been recognised through clinical disease…

http://web.archive.org/web/20040904150118/www.bseinquiry.gov.uk/files/yb/1990/08/23002001.pdf

we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action…

http://web.archive.org/web/20030822031154/www.bseinquiry.gov.uk/files/yb/1990/09/10007001.pdf

May I, at the outset, reiterate that we should avoid dissemination of papers relating to this experimental finding to prevent premature release of the information…

http://web.archive.org/web/20030822052332/www.bseinquiry.gov.uk/files/yb/1990/09/11005001.pdf

3. It is particularly important that this information is not passed outside the Department, until Ministers have decided how they wish it to be handled…

http://web.archive.org/web/20030822052438/www.bseinquiry.gov.uk/files/yb/1990/09/12002001.pdf

But it would be easier for us if pharmaceuticals/devices are not directly mentioned at all…

http://web.archive.org/web/20030518170213/www.bseinquiry.gov.uk/files/yb/1990/09/13004001.pdf

Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom.....

http://web.archive.org/web/20030822054419/www.bseinquiry.gov.uk/files/yb/1990/09/21009001.pdf

BSE TO PIGS NEWS RELEASE

http://web.archive.org/web/20030822162313/www.bseinquiry.gov.uk/files/yb/1990/09/24001001.pdf

CONFIDENTIAL

BSE: PRESS PRESENTATION

http://web.archive.org/web/20030822160958/www.bseinquiry.gov.uk/files/yb/1990/09/20003001.pdf

http://web.archive.org/web/20040623191707/www.bseinquiry.gov.uk/files/yb/1990/09/24013001.pdf

http://web.archive.org/web/20030820195733/http://www.bseinquiry.gov.uk/files/yb/1990/09/20010001.pdf

http://web.archive.org/web/20030820195733/http://www.bseinquiry.gov.uk/files/yb/1990/09/25013001.pdf

http://web.archive.org/web/20030820195733/http://www.bseinquiry.gov.uk/files/yb/1990/09/25015001.pdf

INDUSTRY RESPONSE TYPICAL

http://web.archive.org/web/20030822055917/www.bseinquiry.gov.uk/files/yb/1990/09/25007001.pdf

DEFENSIVE BRIEFING

http://web.archive.org/web/20030820195733/http://www.bseinquiry.gov.uk/files/yb/1990/09/25016001.pdf

CONFIDENTIAL

pigs & pharmaceuticals

http://web.archive.org/web/20010305223234/www.bseinquiry.gov.uk/files/yb/1990/09/10007001.pdf

http://web.archive.org/web/20010305223234/www.bseinquiry.gov.uk/files/yb/1990/08/23002001.pdf

http://web.archive.org/web/20010305223234/www.bseinquiry.gov.uk/files/yb/1990/08/23004001.pdf

http://web.archive.org/web/20010305223234/www.bseinquiry.gov.uk/files/yb/1990/08/29003001.pdf

COMMERCIAL IN CONFIDENCE COMMITTEE ON SAFETY OF MEDICINE NOT FOR PUBLICATION BOVINE SPONGIFORM ENCEPHALOPATHY WORKING GROUP

There are only two products using porcine brain and these use corticotrophin BP, made from porcine pituitary, source from outside the UK...

http://web.archive.org/web/20040622220349/www.bseinquiry.gov.uk/files/yb/1990/10/31003001.pdf

snip...

7 OF 10 LITTLE PIGGIES WENT ON TO DEVELOP BSE;

1: J Comp Pathol. 2000 Feb-Apr; 122(2-3): 131-43. Related Articles,

The neuropathology of experimental bovine spongiform encephalopathy in the pig.

Ryder SJ, Hawkins SA, Dawson M, Wells GA.

Veterinary Laboratories Agency Weybridge, Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, UK.

In an experimental study of the transmissibility of BSE to the pig, seven of 10 pigs, infected at 1-2weeks of age by multiple-route parenteral inoculation with a homogenate of bovine brain from natural BSE cases developed lesions typical of spongiform encephalopathy. The lesions consisted principally of severe neuropil vacuolation affecting most areas of the brain, but mainly the forebrain. In addition, some vacuolar change was identified in the rostral colliculi and hypothalamic areas of normal control pigs. PrP accumulations were detected immunocytochemically in the brains of BSE-infected animals. PrP accumulation was sparse in many areas and its density was not obviously related to the degree of vacuolation. The patterns of PrP immunolabelling in control pigs differed strikingly from those in the infected animals.

PMID: 10684682 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?holding=npg&cmd=Retrieve&db=PubMed&list_uids=10684682&dopt=Abstract

The current feed ban in the U.S. is based exclusively on keeping tissues from TSE infected cattle from entering animal feeds. These results indicating the susceptibility of pigs to CWD, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health.

https://www.ars.usda.gov/research/publications/publication/?seqNo115=353091

https://www.ars.usda.gov/research/project/?accnNo=432011&fy=2017

https://www.ars.usda.gov/research/publications/publication/?seqNo115=337105

https://www.ars.usda.gov/research/publications/publication/?seqNo115=326166

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

Infectious prions in brains and muscles of domestic pigs experimentally challenged with the BSE, scrapie, and CWD agents

https://prpsc.proboards.com/thread/179/scrapie-prions-brains-muscles-pigs

https://transmissiblespongiformencephalopathy.blogspot.com/2025/08/infectious-prions-in-brains-and-muscles.html

Greetings USDA et al @ FY 2025 Plant Pest and Disease Management and Disaster Prevention Program (PPDMDPP) and National Clean Plant Network (NCPN) program,

With great urgency, I kindly wish to submit my concerns with FY 2025 Plant Pest and Disease Management and Disaster Prevention Program (PPDMDPP) and National Clean Plant Network (NCPN) program, with relations to some plants and such that have been omitted from said program, and why with great urgency they should/must be addressed, concerning Transmissible Spongiform Encephalopathy TSE Prion disease, Chronic Wasting Disease, Environmental Contamination, and updated of the TSE Prion via plants, namely the ones i am concerned with, in which have been omitted.

Countries have already started to raise concern with Hay and Straw from locations where Chronic Wasting Disease CWD TSE Prion has been detected, and have ask that said plants must be accompanied by a certificate from a public veterinarian that the product has been harvested in states or provinces where Chronic Wasting Disease has not been detected on deer (see reference materials below).

But, with CWD TSE Prion spreading without control across North America, Korea, Norway, Finland, and Sweden, the fact that plant uptake of the CWD TSE Prion, and transmission there from, has been proven in testing, along with the fact that spillover of CWD TSE Prion to other species, by oral routes, i.e. Humans, Monkeys, Cattle, Sheep, Pigs, rodents, raccoons, I believe that it is extremely important to add TSE Prion Disease to the FY 2025 Plant Pest and Disease Management and Disaster Prevention Program (PPDMDPP) and National Clean Plant Network (NCPN) program, without hesitation....

Thank You Kindly, Terry S. Singeltary Sr., Bacliff, Texas 77518flounder9@verizon.net

“In addition, hay and straw from the United States and Canada must be accompanied by a certificate from a public veterinarian that the product has been harvested in states or provinces where Chronic Wasting Disease has not been detected on deer.”

Regulation No. 1599 of 2018 on additional requirements for the import of hay and straw for used for animal feed. Country Norway Type of law Regulation Source FAO , FAOLEX In addition, hay and straw from the United States and Canada must be accompanied by a certificate from a public veterinarian that the product has been harvested in states or provinces where Chronic Wasting Disease has not been detected on deer.

http://faolex.fao.org/docs/pdf/nor189761.pdf (see full text below)

9 Carrot plants as potential vectors for CWD transmission.

Paulina Soto1,2, Francisca Bravo-Risi1,2, Claudio Soto1, Rodrigo Morales1,2 1Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, USA. 2Universidad Bernardo O’Higgins, Santiago, Chile

***> We show that edible plant components can absorb prions from CWD-contaminated soils and transport them to their aerial parts.

***> Our results indicate that edible plants could participate as vectors of CWD transmission

9 Carrot plants as potential vectors for CWD transmission.

Paulina Soto1,2, Francisca Bravo-Risi1,2, Claudio Soto1, Rodrigo Morales1,2 1Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, USA.

2Universidad Bernardo O’Higgins, Santiago, Chile

Abstract

Chronic wasting disease is a prion disease affecting cervids captive and free-range. CWD is thought to be caused by indirect exposure to contaminated environments. Many studies have shown that infectious prions can enter the environment through saliva, feces, or urine from infected animals and decaying carcasses. However, we need to understand the specific contribution of this component to disease transmission events. Plants are logical environmental components to be evaluated since they grow in environments contaminated with CWD prions and are relevant for transmission. The main objective of this study is to characterize whether prions are transported to the roots and leaves of carrots, an edible plant commonly used in the human diet and as deer bait. We have grown carrot plants in CWD-infected soils. We harvested the carrots and separated them from the leaves. These materials were interrogated for their prion seeding activity using the PMCA. Infectivity was evaluated in mouse bioassays (intracerebral injections in Tg1536 mice). The PMCA analysis demonstrated CWD seeding activity in soils contaminated with CWD prions and in carrot plants (leaves and roots) grown on them. Bioassays showed that both plants and roots contained CWD prions sufficiently to induce disease. As expected, animals treated with prion-infected soils developed prion disease at shorter incubation periods (and complete attack rates) compared to plant components. We show that edible plant components can absorb prions from CWD-contaminated soils and transport them to their aerial parts. Our results indicate that edible plants could participate as vectors of CWD transmission.

=====

15 Detection of CWD prions in plants collected from white-tailed deer farms

Francisca Bravo-Risi1,2, Paulina Soto1,2, Yumeng Huang1, Tracy A. Nichols3, Rodrigo Morales1,4

1Department of Neurology, The University of Texas Health Science Center at Houston, Houston, USA.

2Universidad Bernardo O’Higgins, Doctorado en Ciencias con Mención en Materiales Funcionales, Santiago, Chile. 3Veterinary Services Cervid Health Program, United States Department of Agriculture, Animal and Plant Health Inspection Service, Fort Collins, USA. 4Centro Integrativo de Biologia y Quimica Aplicada (CIBQA), Universidad Bernardo O’Higgins, Santiago, Chile

Abstract

Chronic wasting disease (CWD) is a prion disease affecting captive and free-ranging cervids. Transmission of CWD is thought to occur by direct animal-to-animal contact and by exposure to contaminated environmental fomites. CWD-prions are spread into the environment through biological fluids, excreta, and decaying carcasses. Extensive studies demonstrate that soils adsorb infectious prions which can remain attached for extended periods. Accordingly, prion seeding activity has been detected in natural and experimental samples including mineral licks, water sources, and dust. Although, detection of prion in plants under experimental conditions was demonstrated, the role of plants in CWD spreading has been poorly explored. In the present study, we optimized the detection of CWD-prions in plants using the protein misfolding cyclic amplification (PMCA) technology. Specifically, we compared NaPTA pretreatments and direct spiking of the sample into the PMCA reactions. After achieving technical optimizations, we screened multiple plant specimens collected from white-tailed deer breeding facilities displaying variable CWD prevalence. Our results demonstrated that CWD-prion detection for plants was optimal when samples were pre-treated with a NaPTA PrPSc enriching procedure. Our screening results showed positive PMCA activity for specimens collected from the farm with the highest CWD prevalence. Plants from the same site were tested for infectivity in meadow voles, a co-existing animal species that feeds from grass plants. Although meadow voles were highly susceptible to CWD prions by intra-cerebral administration, ingestion of contaminated grass did not induce prion replication in these rodents. These findings further contribute to understand the role of plants in CWD-prion transmission.

https://intcwdsympo.files.wordpress.com/2023/06/final-agenda-with-abstracts.pdf?force_download=true

Carrot plants as potential vectors for CWD transmission

Paulina Sotoa,b, Francisca Bravo-Risia,b, Claudio Sotoa, and Rodrigo Moralesa,b

aDepartment of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Texas, USA; bUniversidad Bernardo O’Higgins, Santiago, Chile

Prion diseases are infectious neurodegenerative disorders afflicting humans and other mammals. These diseases are generated by the misfolding of the cellular prion protein into a disease-causing isoform. Chronic wasting disease (CWD) is a prevalent prion disease affecting cervids (captive and free-range). CWD is thought to be transmitted through direct animal contact or by indirect exposure to contaminated environments. Many studies have shown that infectious prions can enter the environment through saliva, feces, or urine from infected animals and decaying carcasses. However, we do not fully understand the specific contribution of each component to disease transmission events. Plants are logical environmental components to be evaluated since they grow in environments contaminated with CWD prions and are relevant for animal and human nutrition.

Aims: The main objective of this study is to study whether prions are transported to the roots and leaves of carrots, an edible plant commonly used in the human diet and as deer bait.

Methods: We have grown carrot plants in CWD-infected soils. After 90 days, we harvested the carrots and separated them from the leaves. The experiment was controlled by growing plants in soil samples treated with brain extracts from healthy animals. These materials were interrogated for their prion seeding activity using the Protein Misfolding Cyclic Amplification (PMCA) technique. Infectivity was evaluated in mouse bioassays (intracerebral injections in Tg1536 mice). The animals were sacrificed when they showed established signs of prion disease. Animals not displaying clinical signs were sacrificed at 600 days post-inoculation.

Results: The PMCA analysis demonstrated CWD seeding activity in soils contaminated with CWD prions, as well as in carrot plants (leaves and roots) grown on them. Bioassays demonstrated that both leaves and roots contained CWD prions in sufficient quantities to induce disease (92% attack rate). As expected, animals treated with prion-infected soils developed prion disease at shorter incubation periods (and complete attack rates) compared to plant components. Animals treated with soil and plant components exposed with CWD-free brain extracts did not display prion-associated clinical signs or evidence of sub-clinical prion infection.

Conclusions: We show that edible plant components can absorb prions from CWD contaminated soils and transport them to their aerial parts. Our results indicate that plants could participate as vectors of CWD transmission. Importantly, plants designated for human consumption represent a risk of introducing CWD prions into the human food chain.

Funded by: NIH

Grant number: R01AI132695

https://www.tandfonline.com/doi/full/10.1080/19336896.2022.2091286

P.157: Uptake of prions into plants

Christopher Johnson1, Christina Carlson1, Matthew Keating1,2, Nicole Gibbs1, Haeyoon Chang1, Jamie Wiepz1, and Joel Pedersen1 1USGS National Wildlife Health Center; Madison, WI USA; 2University of Wisconsin - Madison; Madison, WI USA

Soil may preserve chronic wasting disease (CWD) and scrapie infectivity in the environment, making consumption or inhalation of soil particles a plausible mechanism whereby na€ıve animals can be exposed to prions. Plants are known to absorb a variety of substances from soil, including whole proteins, yet the potential for plants to take up abnormal prion protein (PrPTSE) and preserve prion infectivity is not known. In this study, we assessed PrPTSE uptake into roots using laser scanning confocal microscopy with fluorescently tagged PrPTSE and we used serial protein misfolding cyclic amplification (sPMCA) and detect and quantify PrPTSE levels in plant aerial tissues. Fluorescence was identified in the root hairs of the model plant Arabidopsis thaliana, as well as the crop plants alfalfa (Medicago sativa), barley (Hordeum vulgare) and tomato (Solanum lycopersicum) upon exposure to tagged PrPTSE but not a tagged control preparation. Using sPMCA, we found evidence of PrPTSE in aerial tissues of A. thaliana, alfalfa and maize (Zea mays) grown in hydroponic cultures in which only roots were exposed to PrPTSE. Levels of PrPTSE in plant aerial tissues ranged from approximately 4 £ 10 ¡10 to 1 £ 10 ¡9 g PrPTSE g ¡1 plant dry weight or 2 £ 105 to 7 £ 106 intracerebral ID50 units g ¡1 plant dry weight. Both stems and leaves of A. thaliana grown in culture media containing prions are infectious when intracerebrally-injected into mice.

***Our results suggest that prions can be taken up by plants and that contaminated plants may represent a previously unrecognized risk of human, domestic species and wildlife exposure to prions.

===========

***Our results suggest that prions can be taken up by plants and that contaminated plants may represent a previously unrecognized risk of human, domestic species and wildlife exposure to prions.

DISCUSSION

This study shows that plants can efficiently bind prions contained in brain extracts from diverse prion infected animals, including CWD-affected cervids. PrPSc attached to leaves and roots from wheat grass plants remains capable of seeding prion replication in vitro. Surprisingly, the small quantity of PrPSc naturally excreted in urine and feces from sick hamster or cervids was enough to efficiently contaminate plant tissue. Indeed, our results suggest that the majority of excreted PrPSc is efficiently captured by plants’ leaves and roots. Moreover, leaves can be contaminated by spraying them with a prion-containing extract, and PrPSc remains detectable in living plants for as long as the study was performed (several weeks). Remarkably, prion contaminated plants transmit prion disease to animals upon ingestion, producing a 100% attack rate and incubation periods not substantially longer than direct oral administration of sick brain homogenates. Finally, an unexpected but exciting result was that plants were able to uptake prions from contaminated soil and transport them to aerial parts of the plant tissue. Although it may seem farfetched that plants can uptake proteins from the soil and transport it to the parts above the ground, there are already published reports of this phenomenon (McLaren et al., 1960; Jensen and McLaren, 1960; Paungfoo-Lonhienne et al., 2008). The high resistance of prions to degradation and their ability to efficiently cross biological barriers may play a role in this process. The mechanism by which plants bind, retain, uptake, and transport prions is unknown. We are currently studying the way in which prions interact with plants using purified, radioactively labeled PrPSc to determine specificity of the interaction, association constant, reversibility, saturation, movement, etc.

Epidemiological studies have shown numerous instances of scrapie or CWD recurrence upon reintroduction of animals on pastures previously exposed to prion-infected animals. Indeed, reappearance of scrapie has been documented following fallow periods of up to 16 years (Georgsson et al., 2006), and pastures were shown to retain infectious CWD prions for at least 2 years after exposure (Miller et al., 2004). It is likely that the environmentally mediated transmission of prion diseases depends upon the interaction of prions with diverse elements, including soil, water, environmental surfaces, various invertebrate animals, and plants. However, since plants are such an important component of the environment and also a major source of food for many animal species, including humans, our results may have far-reaching implications for animal and human health. Currently, the perception of the risk for animal-to-human prion transmission has been mostly limited to consumption or exposure to contaminated meat; our results indicate that plants might also be an important vector of transmission that needs to be considered in risk assessment.

snip...see full text here ;

http://www.cell.com/cell-reports/pdf/S2211-1247(15)00437-4.pdf

Grass Plants Bind, Retain, Uptake, and Transport Infectious Prions

http://www.cell.com/cell-reports/pdfExtended/S2211-1247(15)00437-4

SEAC seac.gov.uk/minutes/final91.pdf PRION UPDATE VIA VEGETABLE PLANTS FROM THE SOIL

56. Members considered that there is no evidence that crops grown on the land which received composted excreta from BSE-challenged animals pose a TSE risk to humans or animals. One member suggested that, as some of these animals are orally challenged with high doses of BSE-infected materials, and the distribution of infectivity in the digestive system is not completely understood, it might be premature to conclude that there is no infective agent in the manure.

Furthermore, an unpublished study had indicated low level absorption of PrP from soil by tomato plants although it should be noted that this study had not been repeated. Details of this work would be sent to the SEAC Secretary. Dr Matthews explained that most of the manure from animals challenged with high doses of BSE had already been composted and used for coppicing. Members agreed that the risks from disposal of residual manure from experimental animals would be much less than historic risks of on farm contamination from naturally infected animals at the height of the BSE epidemic. ...SNIP...END

https://web.archive.org/web/20070623223549/http://www.seac.gov.uk/minutes/final91.pdf

In addition, hay and straw from the United States and Canada must be accompanied by a certificate from a public veterinarian that the product has been harvested in states or provinces where Chronic Wasting Disease has not been detected on deer.”

Regulation No. 1599 of 2018 on additional requirements for the import of hay and straw for used for animal feed.

This content is exclusively provided by

FAO, FAOLEX

Regulation No. 1599 of 2018 on additional requirements for the import of hay and straw for used for animal feed.

Country Norway

Type of law Regulation

Source

FAO , FAOLEX

Abstract

This Regulation seeks to prevent the spread of infectious animal diseases that can be caused by the importation of hay and straw used in animal feed from countries outside the European Economic Area. Hay and straw imported into Norway as animal feed must: (a) be accompanied by a confirmation from the manufacturer that the product has been stored for at least two months in the country of dispatch and harvested from farms where no animal manure has been fertilized during the past two years; and b) be accompanied by a certificate from a public veterinarian in the country of dispatch that the product has been harvested from farms where no restrictions have been set due to infectious animal disease. In addition, hay and straw from the United States and Canada must be accompanied by a certificate from a public veterinarian that the product has been harvested in states or provinces where Chronic Wasting Disease has not been detected on deer.

Attached files

http://faolex.fao.org/docs/pdf/nor189761.pdf

Web site

http://www.lovdata.no

Date of text

22 Oct 2018

Repealed

No

Source language

English

Legislation Amendment

No

Original title

Forskrift om tilleggskrav ved import av høy og halm til dyrefôr.

Amends

Regulation prohibiting the importation of animals and infectious objects. on 22 Oct 2018

https://leap.unep.org/countries/no/national-legislation/regulation-no-1599-2018-additional-requirements-import-hay-and

"Additionally, we have determined that prion seeding activity is retained for at least fifteen years at a contaminated site following attempted remediation."

Detection of prions in soils contaminated by multiple routes

Stuart Siegfried Lichtenberg1,2 , Heather Inzalaco3 , Sam Thomas4 , Dan Storm5 , Dan Walsh6

1Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, Minnesota, U.S.A.

2Minnesota Center for Prion Research and Outreach, University of Minnesota, St. Paul, Minnesota, U.S.A.

3 Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, U.S.A

4Department of Soil Science, University of Wisconsin-Madison, Madison, Wisconsin, U.S.A.

5Wisconsin Department of Natural Resources, Eau Claire, Wisconsin, U.S.A.

6U.S. Geological Survey, Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, Montana, U.S.A.

Aims: Free-ranging animals afflicted with transmissible spongiform encephalopathies frequently shed infectious prions into the broader environment. The quintessential example is chronic wasting disease, the TSE of cervids. Over the course of the disease, an infected animal will shed infectious prions in blood, urine, saliva, and feces. Upon death, the total prion load interred in the animal’s tissues will be deposited wherever the animal falls. This contamination creates substantial risk to naïve animals, and likely contributes to disease spread. Identification and quantification of prions at contamination hotspots is essential for any attempt at mitigation of environmental transmission.

Materials and Methods: Surfactant extraction of soils followed by precipitation yields a sample that is amenable to analysis by real-time quaking induced conversion. However, differences in extraction yield are apparent depending on the properties of the matrix from which the prions are being extracted, principally soil clay content.

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

=====end

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/

Front. Vet. Sci., 14 September 2015 | https://doi.org/10.3389/fvets.2015.00032

Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission

In conclusion, the results in the current study indicate that removal of furniture that had been in contact with scrapie-infected animals should be recommended, particularly since cleaning and decontamination may not effectively remove scrapie infectivity (31), even though infectivity declines considerably if the pasture and the field furniture have not been in contact with scrapie-infected sheep for several months. As sPMCA failed to detect PrPSc in furniture that was subjected to weathering, even though exposure led to infection in sheep, this method may not always be reliable in predicting the risk of scrapie infection through environmental contamination.

http://journal.frontiersin.org/article/10.3389/fvets.2015.00032/full

172. Establishment of PrPCWD extraction and detection methods in the farm soil

Conclusions: Our studies showed that PrPCWD persist in 0.001% CWD contaminated soil for at least 4 year and natural CWD-affected farm soil. When cervid reintroduced into CWD outbreak farm, the strict decontamination procedures of the infectious agent should be performed in the environment of CWD-affected cervid habitat.

https://www.tandfonline.com/doi/full/10.1080/19336896.2019.1615197

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

While the disease control measures effectively eliminated prion seeding activity in CWD-affected farms, CWD recurred at two of the 18 remediated farms 4 to 5 years after restocking animals. It remains unclear whether the recurrence of CWD at the two farms was due to residual prions in the environment after the control measures, or the introduction of the infected animals from other farms. This uncertainty is heightened by the annual occurrence of CWD at multiple farms and the absence of a traceability system for farmed cervids.

Keywords: Chronic wasting disease (CWD); NaOH; Protein-misfolding cyclic amplification (PMCA); Republic of Korea; farm; prions; remediation; topsoil.

https://www.tandfonline.com/doi/full/10.1080/19336896.2025.2527588

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

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…

CWD Action Plan National Program 103 Animal Health 2022-2027 UPDATE JANUARY 2026

https://prpsc.proboards.com/thread/189/action-national-program-animal-health

https://chronic-wasting-disease.blogspot.com/2026/01/cwd-action-plan-national-program-103.html

ARS Research Elucidating the Pathobiology and Transmission of Transmissible Spongiform Encephalopathies 2025 Annual Report

***> “This information informs regulatory officials,… 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.” <***

https://transmissiblespongiformencephalopathy.blogspot.com/2025/12/ars-research-elucidating-pathobiology.html

SCRAPIE TSE Prion USA RAPID RESPONSE URGENT UPDATES DECEMBER 25, 2025

https://scrapie-usa.blogspot.com/2025/12/scrapie-tse-prion-usa-rapid-response.html

https://prpsc.proboards.com/thread/186/scrapie-prion-response-urgent-updates

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

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.