Wednesday, October 21, 2015


News Release Media Contact: Steve Lightfoot, 512-389-4701,

Oct. 21, 2015

TPWD Details Plans for Hunter Harvest CWD Sample Collections AUSTIN — Texas hunters wishing to assist with the statewide chronic wasting disease (CWD) monitoring effort this fall can do so by voluntarily taking their harvested deer (or the head of the harvested deer) to a location where Texas Parks and Wildlife Department wildlife biologists will be collecting tissue samples for testing.

A list of collection sites and times is available online at In addition to those established collection locations, biologists will also be conducting localized sampling at various sites throughout the season to meet sampling objectives. For additional information regarding localized CWD sampling efforts during this deer season, please contact your local wildlife biologist (

TPWD has been conducting CWD surveillance on hunter-harvested deer and road-kill deer since 2002, and has a goal to collect tissue samples from at least 8,000 hunter harvested deer throughout the state during the 2015-16 deer season. The general deer hunting season opens Nov. 7. This sampling effort provides TPWD with confidence that CWD is not in the free-ranging deer populations at a significant prevalence rate, if at all.

TPWD would prefer to collect the tissue samples within 24 hours of harvest; however, the appropriate tissue samples will remain viable for a few days if the head is chilled soon after harvest, and remains chilled until the samples can be collected. It is very important that the deer head not be frozen.

Once collected by TPWD biologists, the samples will be submitted to the Texas A&M Veterinary Diagnostic Lab at no cost to the hunter, and test results should be made available to the hunter within 3-4 weeks. A hunter who allows for a CWD sample to be collected will be issued a receipt that can be used to track test results online.

SL 2015-10-21

this is great news the TPWD is doing this. I cannot stress enough to all of you, for the sake of your family and mine, before putting anything in the freezer, have those deer tested for CWD. ...terry


If you haven’t heard by now that Chronic Wasting Disease (CWD) was found in a Texas Whitetailed deer (WTD) captive breeder herd this summer, you must have been detailed to the space station for the past few months. As I write this, we still only have one infected (index) herd identified, but that is all it takes to shake things up in the deer world. We had previously found wild mule deer infected in far west Texas, but they are not related to this situation.

Although the Texas Parks & Wildlife Department (TPWD) permits more than 1,200 deer breeders, it is still a relatively young industry and thus a very close-knit community. As folks work on improving their genetic stock, they engage in lots of dealing and trading with each other.

The result of that is that the index herd did business with more than 10 percent of the industry in the past five years, including buying from 30 possible source herds and selling to 126 breeder or release sites. That makes for quite an imposing task from an epidemiological standpoint. Texas is unique among states that allow captive deer breeding as it also allows “liberation” of deer into larger pasture facilities for breeding or hunting.

Although there is much already known about CWD, there are still many things we don’t know. As the Texas Animal Health Commission (TAHC) veterinarians sat down with our TPWD partners to consider the next step, there were many false assumptions and misunderstandings to avoid in completing an effective sciencebased disease plan.

Although TAHC immediately put hold orders on all exposed and source herds, TPWD stopped all breeder movement temporarily so everyone could catch their breath, and that was the right thing to do. The stoppage put everyone under tight deadlines to get a plan together so deer could be safely released before hunting season. The two agencies sat down and worked more closely together than ever before to deal with the index herd situation and the resumption of breeder movements and liberation movements. The issues were complex and volatile as we tried to balance the protection of health for free-ranging deer, the health of the deer breeder industry and the business continuity for a lucrative emerging industry. Keep in mind that cervid stakeholders are split as to how good of an idea captive deer breeding actually is, so there was a lot of debate on every idea.

The fact that there is no validated live animal test and that the disease (prion) can affect the environment as well as animals weighed heavily on all decisions to be made. Nonetheless, there were some basic tenets of CWD science to help officials, including the fact that the disease does not pose a public health concern, is not transmitted in semen and the longest possible incubation period is five years.

I couldn’t be prouder of the timely decisions derived related to resumption of industry movements with enhanced surveillance standards put into place. The goal was to ensure that any deer herds wanting to release or move animals had significant and recent surveillance testing from their deer. Basically, the more mortality testing a herd did recently, the lesser the hurdle they had to meet with the new standards. The more than 180 breeders enrolled in the TAHC status who test 100% of all mortalities were given a huge head start, and approximately 60 of those with more than five years of testing were released from statewide movement restrictions immediately. Enrollment in the TAHC 100% testing program paid off! (Minimum TPWD movement requirements are only for 20% of mortalities).

For the other 1,200 herds, they had to meet various minimum standards of breeder deer testing, and for the first time, hunter surveillance on liberation sites was incorporated into CWD surveillance. A comprehensive statewide testing program must include all segments of the deer industry, including captive deer, liberated deer behind high fences and free-ranging deer. Through the efforts of TPWD and TAHC, there will be more effective surveillance systems in place for this fall’s liberation calendar, and TPWD has indicated they will expand hunter surveillance as well.

Veterinarians across Texas played a major role in helping with the enhanced surveillance standards put in place by assisting with the sampling of obex and lymph nodes, which are the samples to take post mortem. The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) is also to be commended for outstanding customer service in assuring quick turnaround times for the thousands of tests coming in this fall.

I don’t know how many more infected herds (if any) will be found, and I don’t believe our wild deer in Texas are affected right now, but we must create better surveillance systems regardless. The plan that the industry stakeholders, TPWD and TAHC agreed on to enhance surveillance streams and to get deer moving this fall in a safe fashion is just the beginning of a dynamic process. Next spring, we will revisit all policies related to testing, release protocols and approaches to minimize disease risk after we have more testing information.

I do believe there will be some role for live animal testing down the road in Texas with tonsils, rectal lymphoid tissues and other tests under research. Although they may have to be run more than once, by the time fall 2016 rolls around, we may have drastically altered the state movement plan than was created for 2015.

Detection of disease in other herds, decisions about when or how live tests can be applied to mitigate risk and changing political winds can all move the needle in either direction for this event. In the meantime, I couldn’t be prouder to be part of the veterinary community who managed the disease investigation, developed surveillance standards, created herd plans for source, trace out and liberation sites and, most importantly, ensured veterinary science guided all decisions.


PrPSc Detection and Infectivity in Semen from Scrapie-Infected Sheep


Richard Rubenstein1,5, Marie S Bulgin2, Binggong Chang1, Sharon Sorensen-Melson2, Robert B Petersen3 and Giuseppe LaFauci4 + Author Affiliations


1 SUNY Downstate Medical Center, Brooklyn, NY, USA; 2 University of Idaho, Caldwell, ID, USA; 3 Case Western Reserve University, Cleveland, OH, USA; 4 NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA ↵5 E-mail: Received 13 October 2011. Accepted 3 February 2012.




A scrapie-positive ewe was found in a flock that had been scrapie free for 13 years, but housed adjacent to scrapie-positive animals, separated by a wire fence. Live animal testing of the entire flock of 24 animals revealed 7 more subclinical scrapie-positive ewes. We hypothesized that they may have contracted the disease from scrapie-positive rams used for breeding four months prior, possibly through the semen. The genotypes of the ewe flock were highly scrapie-susceptible and the rams were infected with the "Caine" Scrapie Strain having a short incubation time of 4.3-14.6 mo. in sheep with 136/171 VQ/VQ and AQ/VQ genotypes. PrPSc accumulates in a variety of tissues in addition to the central nervous system. Although transmission of prion diseases, or transmissible spongiform encephalopathies, has been achieved via peripheral organ or tissue homogenates as well as by blood transfusion, neither infectivity nor PrPSc have been found in semen from scrapie-infected animals. Using serial protein misfolding cyclic amplification followed by a surround optical fiber immunoassay, we demonstrate that semen from rams infected with a short incubation time scrapie strain contains prion disease-associated seeding activity that generated PrPSc in sPMCA. Injection of the ovinized transgenic mouse line TgSShpPrP with semen from scrapie-infected sheep resulted in PrPSc seeding activity in clinical and, probably as a result of the low titer, nonclinical mouse brain. These results suggest that the transmissible agent, or at least the seeding activity, for sheep scrapie is present in semen. This may be a strain specific phenomenon.



*** 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.







Title: Transmission of chronic wasting disease to sentinel reindeer (Rangifer tarandus tarandus)




item Moore, S - item Kunkle, Robert item Nicholson, Eric item Richt, Juergen item Hamir, Amirali item Waters, Wade item Greenlee, Justin


Submitted to: American College of Veterinary Pathologists Meeting Publication Type: Abstract Only Publication Acceptance Date: August 12, 2015 Publication Date: N/A


Technical Abstract: Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of North American cervids. Reindeer (Rangifer tarandus tarandus) are susceptible to CWD following oral challenge, but CWD has not been reported in free-ranging caribou (Rangifer tarandus caribou) or farmed reindeer. Potential contact between CWD-affected cervids and Rangifer species that are free-ranging or co-housed on farms presents a potential risk of CWD transmission. The aims of this study were to 1) investigate the transmission of CWD from white-tailed deer (Odocoileus virginianus; CWD-wtd), mule deer (Odocoileus hemionus; CWD-md), or elk (Cervus elaphus nelsoni; CWD-elk) to reindeer via the intracranial route, and 2) to assess for direct and indirect horizontal transmission to non-inoculated sentinels. Three groups of 5 reindeer fawns were challenged intracranially with CWD-wtd, CWD-md, or CWD-elk. Two years after challenge of inoculated reindeer, non-inoculated control reindeer were introduced into the same pen as the CWD-wtd inoculated reindeer (n=4) or into a pen adjacent to the CWD-md inoculated reindeer (n=2). Reindeer were allowed to develop clinical disease. At death/euthanasia a complete necropsy examination was performed, including immunohistochemical testing of tissues for disease-associated CWD prion protein (PrP-CWD). Intracranially challenged reindeer developed clinical disease from 21 months post-inoculation (MPI). ***PrP-CWD was detected in 5/6 sentinel reindeer although only 2/6 developed clinical disease during the study period (<57 and="" are="" both="" can="" cervid="" cwd="" directly="" div="" from="" have="" indirectly.="" mpi="" naive="" reindeer="" shown="" sources="" susceptible="" that="" to="" transmit="" various="" we="">


***PrP-CWD was detected in 5/6 sentinel reindeer although only 2/6 developed clinical disease during the study period (<57 and="" are="" both="" can="" cervid="" cwd="" directly="" div="" from="" have="" indirectly.="" mpi="" naive="" reindeer="" shown="" sources="" susceptible="" that="" to="" transmit="" various="" we="">



snip...see more here;


Tuesday, September 29, 2015


*** Transmission of chronic wasting disease to sentinel reindeer (Rangifer tarandus tarandus) can transmit CWD to naive reindeer both directly and indirectly





*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years ***


Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3



*** 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.







The CWD infection rate was nearly 80%, the highest ever in a North American captive herd.


RECOMMENDATION: That the Board approve the purchase of 80 acres of land for $465,000 for the Statewide Wildlife Habitat Program in Portage County and approve the restrictions on public use of the site.





For Immediate Release Thursday, October 2, 2014


Dustin Vande Hoef 515/281-3375 or 515/326-1616 (cell) or


*** TEST RESULTS FROM CAPTIVE DEER HERD WITH CHRONIC WASTING DISEASE RELEASED 79.8 percent of the deer tested positive for the disease


DES MOINES – The Iowa Department of Agriculture and Land Stewardship today announced that the test results from the depopulation of a quarantined captive deer herd in north-central Iowa showed that 284 of the 356 deer, or 79.8% of the herd, tested positive for Chronic Wasting Disease (CWD).



*** see history of this CWD blunder here ;



On June 5, 2013, DNR conducted a fence inspection, after gaining approval from surrounding landowners, and confirmed that the fenced had been cut or removed in at least four separate locations; that the fence had degraded and was failing to maintain the enclosure around the Quarantined Premises in at least one area; that at least three gates had been opened;and that deer tracks were visible in and around one of the open areas in the sand on both sides of the fence, evidencing movement of deer into the Quarantined Premises.



The overall incidence of clinical CWD in white-tailed deer was 82%


Species (cohort) CWD (cases/total) Incidence (%) Age at CWD death (mo)



”The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite it’s subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA veiwed it as a wildlife problem and consequently not their province!” page 26.



Sunday, January 06, 2013




*** "it‘s no longer its business.”



CWD, spreading it around...


for the game farm industry, and their constituents, to continue to believe that they are _NOT_, and or insinuate that they have _NEVER_ been part of the problem, will only continue to help spread cwd. the game farming industry, from the shooting pens, to the urine mills, the antler mills, the sperm mills, velvet mills, shooting pens, to large ranches, are not the only problem, but it is painfully obvious that they have been part of the problem for decades and decades, just spreading it around, as with transportation and or exportation and or importation of cervids from game farming industry, and have been proven to spread cwd. no one need to look any further than South Korea blunder ;




spreading cwd around...


Between 1996 and 2002, chronic wasting disease was diagnosed in 39 herds of farmed elk in Saskatchewan in a single epidemic. All of these herds were depopulated as part of the Canadian Food Inspection Agency’s (CFIA) disease eradication program. Animals, primarily over 12 mo of age, were tested for the presence CWD prions following euthanasia. Twenty-one of the herds were linked through movements of live animals with latent CWD from a single infected source herd in Saskatchewan, 17 through movements of animals from 7 of the secondarily infected herds.


***The source herd is believed to have become infected via importation of animals from a game farm in South Dakota where CWD was subsequently diagnosed (7,4). A wide range in herd prevalence of CWD at the time of herd depopulation of these herds was observed. Within-herd transmission was observed on some farms, while the disease remained confined to the introduced animals on other farms.



spreading cwd around...


Friday, May 13, 2011


Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea


Hyun-Joo Sohn, Yoon-Hee Lee, Min-jeong Kim, Eun-Im Yun, Hyo-Jin Kim, Won-Yong Lee, Dong-Seob Tark, In- Soo Cho, Foreign Animal Disease Research Division, National Veterinary Research and Quarantine Service, Republic of Korea


Chronic wasting disease (CWD) has been recognized as an important prion disease in native North America deer and Rocky mountain elks. The disease is a unique member of the transmissible spongiform encephalopathies (TSEs), which naturally affects only a few species. CWD had been limited to USA and Canada until 2000.


On 28 December 2000, information from the Canadian government showed that a total of 95 elk had been exported from farms with CWD to Korea. These consisted of 23 elk in 1994 originating from the so-called “source farm” in Canada, and 72 elk in 1997, which had been held in pre export quarantine at the “source farm”.Based on export information of CWD suspected elk from Canada to Korea, CWD surveillance program was initiated by the Ministry of Agriculture and Forestry (MAF) in 2001.


All elks imported in 1997 were traced back, however elks imported in 1994 were impossible to identify. CWD control measures included stamping out of all animals in the affected farm, and thorough cleaning and disinfection of the premises. In addition, nationwide clinical surveillance of Korean native cervids, and improved measures to ensure reporting of CWD suspect cases were implemented.


Total of 9 elks were found to be affected. CWD was designated as a notifiable disease under the Act for Prevention of Livestock Epidemics in 2002.


Additional CWD cases - 12 elks and 2 elks - were diagnosed in 2004 and 2005.


Since February of 2005, when slaughtered elks were found to be positive, all slaughtered cervid for human consumption at abattoirs were designated as target of the CWD surveillance program. Currently, CWD laboratory testing is only conducted by National Reference Laboratory on CWD, which is the Foreign Animal Disease Division (FADD) of National Veterinary Research and Quarantine Service (NVRQS).


In July 2010, one out of 3 elks from Farm 1 which were slaughtered for the human consumption was confirmed as positive. Consequently, all cervid – 54 elks, 41 Sika deer and 5 Albino deer – were culled and one elk was found to be positive. Epidemiological investigations were conducted by Veterinary Epidemiology Division (VED) of NVRQS in collaboration with provincial veterinary services.


Epidemiologically related farms were found as 3 farms and all cervid at these farms were culled and subjected to CWD diagnosis. Three elks and 5 crossbreeds (Red deer and Sika deer) were confirmed as positive at farm 2.


All cervids at Farm 3 and Farm 4 – 15 elks and 47 elks – were culled and confirmed as negative.


Further epidemiological investigations showed that these CWD outbreaks were linked to the importation of elks from Canada in 1994 based on circumstantial evidences.


In December 2010, one elk was confirmed as positive at Farm 5. Consequently, all cervid – 3 elks, 11 Manchurian Sika deer and 20 Sika deer – were culled and one Manchurian Sika deer and seven Sika deer were found to be positive. This is the first report of CWD in these sub-species of deer. Epidemiological investigations found that the owner of the Farm 2 in CWD outbreaks in July 2010 had co-owned the Farm 5.


In addition, it was newly revealed that one positive elk was introduced from Farm 6 of Jinju-si Gyeongsang Namdo. All cervid – 19 elks, 15 crossbreed (species unknown) and 64 Sika deer – of Farm 6 were culled, but all confirmed as negative.






New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication


The infectious agents responsible for transmissible spongiform encephalopathy (TSE) are notoriously resistant to most physical and chemical methods used for inactivating pathogens, including heat. It has long been recognized, for example, that boiling is ineffective and that higher temperatures are most efficient when combined with steam under pressure (i.e., autoclaving). As a means of decontamination, dry heat is used only at the extremely high temperatures achieved during incineration, usually in excess of 600°C. It has been assumed, without proof, that incineration totally inactivates the agents of TSE, whether of human or animal origin.



Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production


Histochemical analysis of hamster brains inoculated with the solid residue showed typical spongiform degeneration and vacuolation. Re-inoculation of these brains into a new cohort of hamsters led to onset of clinical scrapie symptoms within 75 days, suggesting that the specific infectivity of the prion protein was not changed during the biodiesel process. The biodiesel reaction cannot be considered a viable prion decontamination method for MBM, although we observed increased survival time of hamsters and reduced infectivity greater than 6 log orders in the solid MBM residue. Furthermore, results from our study compare for the first time prion detection by Western Blot versus an infectivity bioassay for analysis of biodiesel reaction products. We could show that biochemical analysis alone is insufficient for detection of prion infectivity after a biodiesel process.



Detection of protease-resistant cervid prion protein in water from a CWD-endemic area


The data presented here demonstrate that sPMCA can detect low levels of PrPCWD in the environment, corroborate previous biological and experimental data suggesting long term persistence of prions in the environment2,3 and imply that PrPCWD accumulation over time may contribute to transmission of CWD in areas where it has been endemic for decades. This work demonstrates the utility of sPMCA to evaluate other environmental water sources for PrPCWD, including smaller bodies of water such as vernal pools and wallows, where large numbers of cervids congregate and into which prions from infected animals may be shed and concentrated to infectious levels.



A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing


Keywords:Abattoir;bovine spongiform encephalopathy;QRA;scrapie;TSE


In this article the development and parameterization of a quantitative assessment is described that estimates the amount of TSE infectivity that is present in a whole animal carcass (bovine spongiform encephalopathy [BSE] for cattle and classical/atypical scrapie for sheep and lambs) and the amounts that subsequently fall to the floor during processing at facilities that handle specified risk material (SRM). BSE in cattle was found to contain the most oral doses, with a mean of 9864 BO ID50s (310, 38840) in a whole carcass compared to a mean of 1851 OO ID50s (600, 4070) and 614 OO ID50s (155, 1509) for a sheep infected with classical and atypical scrapie, respectively. Lambs contained the least infectivity with a mean of 251 OO ID50s (83, 548) for classical scrapie and 1 OO ID50s (0.2, 2) for atypical scrapie. The highest amounts of infectivity falling to the floor and entering the drains from slaughtering a whole carcass at SRM facilities were found to be from cattle infected with BSE at rendering and large incineration facilities with 7.4 BO ID50s (0.1, 29), intermediate plants and small incinerators with a mean of 4.5 BO ID50s (0.1, 18), and collection centers, 3.6 BO ID50s (0.1, 14). The lowest amounts entering drains are from lambs infected with classical and atypical scrapie at intermediate plants and atypical scrapie at collection centers with a mean of 3 × 10−7 OO ID50s (2 × 10−8, 1 × 10−6) per carcass. The results of this model provide key inputs for the model in the companion paper published here.





Using in vitro prion replication for high sensitive detection of prions and prionlike proteins and for understanding mechanisms of transmission.


Claudio Soto


Mitchell Center for Alzheimer's diseases and related Brain disorders, Department of Neurology, University of Texas Medical School at Houston.


Prion and prion-like proteins are misfolded protein aggregates with the ability to selfpropagate to spread disease between cells, organs and in some cases across individuals. I n T r a n s m i s s i b l e s p o n g i f o r m encephalopathies (TSEs), prions are mostly composed by a misfolded form of the prion protein (PrPSc), which propagates by transmitting its misfolding to the normal prion protein (PrPC). The availability of a procedure to replicate prions in the laboratory may be important to study the mechanism of prion and prion-like spreading and to develop high sensitive detection of small quantities of misfolded proteins in biological fluids, tissues and environmental samples. Protein Misfolding Cyclic Amplification (PMCA) is a simple, fast and efficient methodology to mimic prion replication in the test tube. PMCA is a platform technology that may enable amplification of any prion-like misfolded protein aggregating through a seeding/nucleation process. In TSEs, PMCA is able to detect the equivalent of one single molecule of infectious PrPSc and propagate prions that maintain high infectivity, strain properties and species specificity. Using PMCA we have been able to detect PrPSc in blood and urine of experimentally infected animals and humans affected by vCJD with high sensitivity and specificity. Recently, we have expanded the principles of PMCA to amplify amyloid-beta (Aβ) and alphasynuclein (α-syn) aggregates implicated in Alzheimer's and Parkinson's diseases, respectively. Experiments are ongoing to study the utility of this technology to detect Aβ and α-syn aggregates in samples of CSF and blood from patients affected by these diseases.




***Recently, we have been using PMCA to study the role of environmental prion contamination on the horizontal spreading of TSEs. These experiments have focused on the study of the interaction of prions with plants and environmentally relevant surfaces. Our results show that plants (both leaves and roots) bind tightly to prions present in brain extracts and excreta (urine and feces) and retain even small quantities of PrPSc for long periods of time. Strikingly, ingestion of prioncontaminated leaves and roots produced disease with a 100% attack rate and an incubation period not substantially longer than feeding animals directly with scrapie brain homogenate. Furthermore, plants can uptake prions from contaminated soil and transport them to different parts of the plant tissue (stem and leaves). Similarly, prions bind tightly to a variety of environmentally relevant surfaces, including stones, wood, metals, plastic, glass, cement, etc. Prion contaminated surfaces efficiently transmit prion disease when these materials were directly injected into the brain of animals and strikingly when the contaminated surfaces were just placed in the animal cage. These findings demonstrate that environmental materials can efficiently bind infectious prions and act as carriers of infectivity, suggesting that they may play an important role in the horizontal transmission of the disease.




Since its invention 13 years ago, PMCA has helped to answer fundamental questions of prion propagation and has broad applications in research areas including the food industry, blood bank safety and human and veterinary disease diagnosis.



see ;







98 | Veterinary Record | January 24, 2015




Scrapie: a particularly persistent pathogen


Cristina Acín


Resistant prions in the environment have been the sword of Damocles for scrapie control and eradication. Attempts to establish which physical and chemical agents could be applied to inactivate or moderate scrapie infectivity were initiated in the 1960s and 1970s,with the first study of this type focusing on the effect of heat treatment in reducing prion infectivity (Hunter and Millson 1964). Nowadays, most of the chemical procedures that aim to inactivate the prion protein are based on the method developed by Kimberlin and collaborators (1983). This procedure consists of treatment with 20,000 parts per million free chlorine solution, for a minimum of one hour, of all surfaces that need to be sterilised (in laboratories, lambing pens, slaughterhouses, and so on). Despite this, veterinarians and farmers may still ask a range of questions, such as ‘Is there an official procedure published somewhere?’ and ‘Is there an international organisation which recommends and defines the exact method of scrapie decontamination that must be applied?’


From a European perspective, it is difficult to find a treatment that could be applied, especially in relation to the disinfection of surfaces in lambing pens of affected flocks. A 999/2001 EU regulation on controlling spongiform encephalopathies (European Parliament and Council 2001) did not specify a particular decontamination measure to be used when an outbreak of scrapie is diagnosed. There is only a brief recommendation in Annex VII concerning the control and eradication of transmissible spongiform encephalopathies (TSE s).


Chapter B of the regulation explains the measures that must be applied if new caprine animals are to be introduced to a holding where a scrapie outbreak has previously been diagnosed. In that case, the statement indicates that caprine animals can be introduced ‘provided that a cleaning and disinfection of all animal housing on the premises has been carried out following destocking’.


Issues around cleaning and disinfection are common in prion prevention recommendations, but relevant authorities, veterinarians and farmers may have difficulties in finding the specific protocol which applies. The European Food and Safety Authority (EFSA ) published a detailed report about the efficacy of certain biocides, such as sodium hydroxide, sodium hypochlorite, guanidine and even a formulation of copper or iron metal ions in combination with hydrogen peroxide, against prions (EFSA 2009). The report was based on scientific evidence (Fichet and others 2004, Lemmer and others 2004, Gao and others 2006, Solassol and others 2006) but unfortunately the decontamination measures were not assessed under outbreak conditions.


The EFSA Panel on Biological Hazards recently published its conclusions on the scrapie situation in the EU after 10 years of monitoring and control of the disease in sheep and goats (EFSA 2014), and one of the most interesting findings was the Icelandic experience regarding the effect of disinfection in scrapie control. The Icelandic plan consisted of: culling scrapie-affected sheep or the whole flock in newly diagnosed outbreaks; deep cleaning and disinfection of stables, sheds, barns and equipment with high pressure washing followed by cleaning with 500 parts per million of hypochlorite; drying and treatment with 300 ppm of iodophor; and restocking was not permitted for at least two years. Even when all of these measures were implemented, scrapie recurred on several farms, indicating that the infectious agent survived for years in the environment, even as many as 16 years after restocking (Georgsson and others 2006).


In the rest of the countries considered in the EFSA (2014) report, recommendations for disinfection measures were not specifically defined at the government level. In the report, the only recommendation that is made for sheep is repopulation with sheep with scrapie-resistant genotypes. This reduces the risk of scrapie recurrence but it is difficult to know its effect on the infection.


Until the EFSA was established (in May 2003), scientific opinions about TSE s were provided by the Scientific Steering Committee (SSC) of the EC, whose advice regarding inactivation procedures focused on treating animal waste at high temperatures (150°C for three hours) and high pressure alkaline hydrolysis (SSC 2003). At the same time, the TSE Risk Management Subgroup of the Advisory Committee on Dangerous Pathogens (ACDP) in the UK published guidance on safe working and the prevention of TSE infection. Annex C of the ACDP report established that sodium hypochlorite was considered to be effective, but only if 20,000 ppm of available chlorine was present for at least one hour, which has practical limitations such as the release of chlorine gas, corrosion, incompatibility with formaldehyde, alcohols and acids, rapid inactivation of its active chemicals and the stability of dilutions (ACDP 2009).


In an international context, the World Organisation for Animal Health (OIE) does not recommend a specific disinfection protocol for prion agents in its Terrestrial Code or Manual. Chapter 4.13 of the Terrestrial Code, General recommendations on disinfection and disinsection (OIE 2014), focuses on foot-and-mouth disease virus, mycobacteria and Bacillus anthracis, but not on prion disinfection. Nevertheless, the last update published by the OIE on bovine spongiform encephalopathy (OIE 2012) indicates that few effective decontamination techniques are available to inactivate the agent on surfaces, and recommends the removal of all organic material and the use of sodium hydroxide, or a sodium hypochlorite solution containing 2 per cent available chlorine, for more than one hour at 20ºC.


The World Health Organization outlines guidelines for the control of TSE s, and also emphasises the importance of mechanically cleaning surfaces before disinfection with sodium hydroxide or sodium hypochlorite for one hour (WHO 1999).


Finally, the relevant agencies in both Canada and the USA suggest that the best treatments for surfaces potentially contaminated with prions are sodium hydroxide or sodium hypochlorite at 20,000 ppm. This is a 2 per cent solution, while most commercial household bleaches contain 5.25 per cent sodium hypochlorite. It is therefore recommended to dilute one part 5.25 per cent bleach with 1.5 parts water (CDC 2009, Canadian Food Inspection Agency 2013).


So what should we do about disinfection against prions? First, it is suggested that a single protocol be created by international authorities to homogenise inactivation procedures and enable their application in all scrapie-affected countries. Sodium hypochlorite with 20,000 ppm of available chlorine seems to be the procedure used in most countries, as noted in a paper summarised on p 99 of this issue of Veterinary Record (Hawkins and others 2015). But are we totally sure of its effectiveness as a preventive measure in a scrapie outbreak? Would an in-depth study of the recurrence of scrapie disease be needed?


What we can conclude is that, if we want to fight prion diseases, and specifically classical scrapie, we must focus on the accuracy of diagnosis, monitoring and surveillance; appropriate animal identification and control of movements; and, in the end, have homogeneous and suitable protocols to decontaminate and disinfect lambing barns, sheds and equipment available to veterinarians and farmers. Finally, further investigations into the resistance of prion proteins in the diversity of environmental surfaces are required.






98 | Veterinary Record | January 24, 2015



Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination


Steve A. C. Hawkins, MIBiol, Pathology Department1, Hugh A. Simmons, BVSc MRCVS, MBA, MA Animal Services Unit1, Kevin C. Gough, BSc, PhD2 and Ben C. Maddison, BSc, PhD3 + Author Affiliations


1Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK 2School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK 3ADAS UK, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK E-mail for correspondence: Abstract Scrapie of sheep/goats and chronic wasting disease of deer/elk are contagious prion diseases where environmental reservoirs are directly implicated in the transmission of disease. In this study, the effectiveness of recommended scrapie farm decontamination regimens was evaluated by a sheep bioassay using buildings naturally contaminated with scrapie. Pens within a farm building were treated with either 20,000 parts per million free chorine solution for one hour or were treated with the same but were followed by painting and full re-galvanisation or replacement of metalwork within the pen. Scrapie susceptible lambs of the PRNP genotype VRQ/VRQ were reared within these pens and their scrapie status was monitored by recto-anal mucosa-associated lymphoid tissue. All animals became infected over an 18-month period, even in the pen that had been subject to the most stringent decontamination process. These data suggest that recommended current guidelines for the decontamination of farm buildings following outbreaks of scrapie do little to reduce the titre of infectious scrapie material and that environmental recontamination could also be an issue associated with these premises.






Thorough pressure washing of a pen had no effect on the amount of bioavailable scrapie infectivity (pen B). The routine removal of prions from surfaces within a laboratory setting is treatment for a minimum of one hour with 20,000 ppm free chlorine, a method originally based on the use of brain macerates from infected rodents to evaluate the effectiveness of decontamination (Kimberlin and others 1983). Further studies have also investigated the effectiveness of hypochlorite disinfection of metal surfaces to simulate the decontamination of surgical devices within a hospital setting. Such treatments with hypochlorite solution were able to reduce infectivity by 5.5 logs to lower than the sensitivity of the bioassay used (Lemmer and others 2004). Analogous treatment of the pen surfaces did not effectively remove the levels of scrapie infectivity over that of the control pens, indicating that this method of decontamination is not effective within a farm setting. This may be due to the high level of biological matrix that is present upon surfaces within the farm environment, which may reduce the amount of free chlorine available to inactivate any infectious prion. Remarkably 1/5 sheep introduced into pen D had also became scrapie positive within nine months, with all animals in this pen being RAMALT positive by 18 months of age. Pen D was no further away from the control pen (pen A) than any of the other pens within this barn. Localised hot spots of infectivity may be present within scrapie-contaminated environments, but it is unlikely that pen D area had an amount of scrapie contamination that was significantly different than the other areas within this building. Similarly, there were no differences in how the biosecurity of pen D was maintained, or how this pen was ventilated compared with the other pens. This observation, perhaps, indicates the slower kinetics of disease uptake within this pen and is consistent with a more thorough prion removal and recontamination. These observations may also account for the presence of inadvertent scrapie cases within other studies, where despite stringent biosecurity, control animals have become scrapie positive during challenge studies using barns that also housed scrapie-affected animals (Ryder and others 2009). The bioassay data indicate that the exposure of the sheep to a farm environment after decontamination efforts thought to be effective in removing scrapie is sufficient for the animals to become infected with scrapie. The main exposure routes within this scenario are likely to be via the oral route, during feeding and drinking, and respiratory and conjunctival routes. It has been demonstrated that scrapie infectivity can be efficiently transmitted via the nasal route in sheep (Hamir and others 2008), as is the case for CWD in both murine models and in white-tailed deer (Denkers and others 2010, 2013). Recently, it has also been demonstrated that CWD prions presented as dust when bound to the soil mineral montmorillonite can be infectious via the nasal route (Nichols and others 2013). When considering pens C and D, the actual source of the infectious agent in the pens is not known, it is possible that biologically relevant levels of prion survive on surfaces during the decontamination regimen (pen C). With the use of galvanising and painting (pen D) covering and sealing the surface of the pen, it is possible that scrapie material recontaminated the pens by the movement of infectious prions contained within dusts originating from other parts of the barn that were not decontaminated or from other areas of the farm.


Given that scrapie prions are widespread on the surfaces of affected farms (Maddison and others 2010a), irrespective of the source of the infectious prions in the pens, this study clearly highlights the difficulties that are faced with the effective removal of environmentally associated scrapie infectivity. This is likely to be paralleled in CWD which shows strong similarities to scrapie in terms of both the dissemination of prions into the environment and the facile mode of disease transmission. These data further contribute to the understanding that prion diseases can be highly transmissible between susceptible individuals not just by direct contact but through highly stable environmental reservoirs that are refractory to decontamination.


The presence of these environmentally associated prions in farm buildings make the control of these diseases a considerable challenge, especially in animal species such as goats where there is lack of genetic resistance to scrapie and, therefore, no scope to re-stock farms with animals that are resistant to scrapie.


Scrapie Sheep Goats Transmissible spongiform encephalopathies (TSE) Accepted October 12, 2014. Published Online First 31 October 2014



Monday, November 3, 2014


Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination





Detection of Environmentally Associated PrPSc on a Farm with Endemic Scrapie


Ben C. Maddison,1 Claire A. Baker,1 Helen C. Rees,1 Linda A. Terry,2 Leigh Thorne,2 Susan J. Belworthy2 and Kevin C. Gough3 1ADAS-UK LTD; Department of Biology; University of Leicester; Leicester, UK; 2Veterinary Laboratories Agency; Surry, KT UK; 3Department of Veterinary Medicine and Science; University of Nottingham; Sutton Bonington, Loughborough UK


Key words: scrapie, evironmental persistence, sPMCA


Ovine scrapie shows considerable horizontal transmission, yet the routes of transmission and specifically the role of fomites in transmission remain poorly defined. Here we present biochemical data demonstrating that on a scrapie-affected sheep farm, scrapie prion contamination is widespread. It was anticipated at the outset that if prions contaminate the environment that they would be there at extremely low levels, as such the most sensitive method available for the detection of PrPSc, serial Protein Misfolding Cyclic Amplification (sPMCA), was used in this study. We investigated the distribution of environmental scrapie prions by applying ovine sPMCA to samples taken from a range of surfaces that were accessible to animals and could be collected by use of a wetted foam swab. Prion was amplified by sPMCA from a number of these environmental swab samples including those taken from metal, plastic and wooden surfaces, both in the indoor and outdoor environment. At the time of sampling there had been no sheep contact with these areas for at least 20 days prior to sampling indicating that prions persist for at least this duration in the environment. These data implicate inanimate objects as environmental reservoirs of prion infectivity which are likely to contribute to disease transmission.



Willingham, Erin McNulty, Kelly Anderson, Jeanette Hayes-Klug, Amy Nalls, and Candace Mathiason Colorado State University; Fort Collins, CO USA


Chronic wasting disease (CWD) is the transmissible spongiform encephalopathy (TSE), of free-ranging and captive cervids (deer, elk and moose).


The presence of infectious prions in the tissues, bodily fluids and environments of clinical and preclinical CWD-infected animals is thought to account for its high transmission efficiency. Recently it has been recognized that mother to offspring transmission may contribute to the facile transmission of some TSEs. Although the mechanism behind maternal transmission is not yet known, the extended asymptomatic TSE carrier phase (lasting years to decades) suggests that it may have implications in the spread of prions.


Placental trafficking and/or secretion in milk are 2 means by which maternal prion transmission may occur. In these studies we explore these avenues during early and late infection using a transgenic mouse model expressing cervid prion protein. Na€ıve and CWD-infected dams were bred at both timepoints, and were allowed to bear and raise their offspring. Milk was collected from the dams for prion analysis, and the offspring were observed for TSE disease progression. Terminal tissues harvested from both dams and offspring were analyzed for prions.


We have demonstrated that


(1) CWDinfected TgCerPRP females successfully breed and bear offspring, and


(2) the presence of PrPCWD in reproductive and mammary tissue from CWD-infected dams.


We are currently analyzing terminal tissue harvested from offspring born to CWD-infected dams for the detection of PrPCWD and amplification competent prions. These studies will provide insight into the potential mechanisms and biological significance associated with mother to offspring transmission of TSEs.




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.***




Friday, May 15, 2015


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







P.19: Characterization of chronic wasting disease isolates from freeranging deer (Odocoileus sp) in Alberta and Saskatchewan, Canada


Camilo Duque Velasquez1, Chiye Kim1, Nathalie Daude1, Jacques van der Merwe1, Allen Herbst1, Trent Bollinger2, Judd Aiken1, and Debbie McKenzie1 1Centre for Prions and Protein Folding Diseases; University of Alberta; Edmonton, Canada; 2Western College of Veterinary Medicine; University of Saskatchewan; Saskatoon, Canada


Chronic wasting disease (CWD) is an emerging prion disease of free ranging and captive species of Cervidae. In North America, CWD is enzootic in some wild cervid populations and can circulate among different deer species. The contagious nature of CWD prions and the variation of cervid PRNP alleles, which influence host susceptibility, can result in the emergence and adaptation of different CWD strains. These strains may impact transmission host range, disease diagnosis, spread dynamics and efficacy of potential vaccines. We are characterizing different CWD agents by biochemical analysis of the PrPCWD conformers, propagation in vitro cell assays1 and by comparing transmission properties and neuropathology in Tg33 (Q95G96) and Tg60 (Q95S96) mice.2 Although Tg60 mice expressing S96- PrPC have been shown resistant to CWD infectivity from various cervid species,2,3


***these transgenic mice are susceptible to H95 C CWD, a CWD strain derived from experimental infection of deer expressing H95G96-PrPC. The diversity of strains present in free-ranging mule deer (Odocoileus hemionus) and white-tailed deer (Odocoileus virginianus) from Alberta and Saskatchewan is being determined and will allow us to delineate the properties of CWD agents circulating in CWD enzootic cervid populations of Canada.




1. van der Merwe J, Aiken J, Westaway D, McKenzie D. The standard scrapie cell assay: Development, utility and prospects. Viruses 2015; 7(1):180–198; PMID:25602372;


2. Meade-White K, Race B, Trifilo M, Bossers A, Favara C, Lacasse R, Miller M, Williams E, Oldstone M, Race R, Chesebro B. Resistance to chronic wasting disease in transgenic mice expressing a naturally occurring allelic variant of deer prion protein. J Virol 2007; 81(9):4533–4539; PMID: 17314157; http://dx.


3. Race B, Meade-White K, Miller MW, Fox KA, Chesebro B. In vivo comparison of chronic wasting disease infectivity from deer with variation at prion protein residue 96. J Virol 2011; 85(17):9235–9238; PMID: 21697479;




***these transgenic mice are susceptible to H95 C CWD, a CWD strain derived from experimental infection of deer expressing H95G96-PrPC.




P.136: Mother to offspring transmission of CWD—Detection in fawn tissues using the QuIC assay


Amy Nalls, Erin McNulty, Clare Hoover, Jeanette Hayes-Klug, Kelly Anderson, Edward Hoover, and Candace Mathiason Colorado State University; Fort Collins, CO USA


To investigate the role mother to offspring transmission plays in chronic wasting disease (CWD), we have employed a small, polyestrous breeding, indoor maintainable cervid model, the Reeves’ muntjac deer. Muntjac doe were inoculated with CWD and tested positive by lymphoid biopsy at 4 months post inoculation. From these CWD-infected doe, we obtained 3 viable fawns. These fawns tested IHC-positive for CWD by lymphoid biopsy as early as 40 d post birth, and all have been euthanized due to clinical disease at 31, 34 and 59 months post birth. The QuIC assay demonstrates sensitivity and specificity in the detection of conversion competent prions in peripheral IHC-positive tissues including tonsil, mandibular, partotid, retropharyngeal, and prescapular lymph nodes, adrenal gland, spleen and liver. In summary, using the muntjac deer model, we have demonstrated CWD clinical disease in offspring born to CWD-infected doe and found that the QuIC assay is an effective tool in the detection of prions in peripheral tissues. ***Our findings demonstrate that transmission of prions from mother to offspring can occur, and may be underestimated for all prion diseases.




***Our findings demonstrate that transmission of prions from mother to offspring can occur, and may be underestimated for all prion diseases.





***our findings suggest that possible transmission risk of H-type BSE to sheep and human. ***


P.86: Estimating the risk of transmission of BSE and scrapie to ruminants and humans by protein misfolding cyclic amplification


Morikazu Imamura, Naoko Tabeta, Yoshifumi Iwamaru, and Yuichi Murayama National Institute of Animal Health; Tsukuba, Japan


To assess the risk of the transmission of ruminant prions to ruminants and humans at the molecular level, we investigated the ability of abnormal prion protein (PrPSc) of typical and atypical BSEs (L-type and H-type) and typical scrapie to convert normal prion protein (PrPC) from bovine, ovine, and human to proteinase K-resistant PrPSc-like form (PrPres) using serial protein misfolding cyclic amplification (PMCA).


Six rounds of serial PMCA was performed using 10% brain homogenates from transgenic mice expressing bovine, ovine or human PrPC in combination with PrPSc seed from typical and atypical BSE- or typical scrapie-infected brain homogenates from native host species. In the conventional PMCA, the conversion of PrPC to PrPres was observed only when the species of PrPC source and PrPSc seed matched. However, in the PMCA with supplements (digitonin, synthetic polyA and heparin), both bovine and ovine PrPC were converted by PrPSc from all tested prion strains. On the other hand, human PrPC was converted by PrPSc from typical and H-type BSE in this PMCA condition.


Although these results were not compatible with the previous reports describing the lack of transmissibility of H-type BSE to ovine and human transgenic mice, ***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.






P.97: Scrapie transmits to white-tailed deer by the oral route and has a molecular profile similar to chronic wasting disease and distinct from the scrapie inoculum


Justin Greenlee1, S Jo Moore1, Jodi Smith1, M Heather West Greenlee2, and Robert Kunkle1 1National Animal Disease Center; Ames, IA USA; 2Iowa State University; Ames, IA USA


The purpose of this work was to determine susceptibility of white-tailed deer (WTD) to the agent of sheep scrapie and to compare the resultant PrPSc to that of the original inoculum and chronic wasting disease (CWD). We inoculated WTD by a natural route of exposure (concurrent oral and intranasal (IN); n D 5) with a US scrapie isolate. All scrapie-inoculated deer had evidence of PrPSc accumulation. PrPSc was detected in lymphoid tissues at preclinical time points, and deer necropsied after 28 months post-inoculation had clinical signs, spongiform encephalopathy, and widespread distribution of PrPSc in neural and lymphoid tissues. Western blotting (WB) revealed PrPSc with 2 distinct molecular profiles. WB on cerebral cortex had a profile similar to the original scrapie inoculum, whereas WB of brainstem, cerebellum, or lymph nodes revealed PrPSc with a higher profile resembling CWD. Homogenates with the 2 distinct profiles from WTD with clinical scrapie were further passaged to mice expressing cervid prion protein and intranasally to sheep and WTD. In cervidized mice, the 2 inocula have distinct incubation times. Sheep inoculated intranasally with WTD derived scrapie developed disease, but only after inoculation with the inoculum that had a scrapie-like profile. The WTD study is ongoing, but deer in both inoculation groups are positive for PrPSc by rectal mucosal biopsy. In summary, this work demonstrates that WTD are susceptible to the agent of scrapie, 2 distinct molecular profiles of PrPSc are present in the tissues of affected deer, and inoculum of either profile readily passes to deer.



Saturday, January 31, 2015


European red deer (Cervus elaphus elaphus) are susceptible to Bovine Spongiform Encephalopathy BSE by Oral Alimentary route



I strenuously once again urge the FDA and its industry constituents, to make it MANDATORY that all ruminant feed be banned to all ruminants, and this should include all cervids as soon as possible for the following reasons...




In the USA, under the Food and Drug Administrations BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system.


***However, this recommendation is guidance and not a requirement by law.




31 Jan 2015 at 20:14 GMT


*** Ruminant feed ban for cervids in the United States? ***


31 Jan 2015 at 20:14 GMT



Saturday, September 12, 2015


In utero transmission and tissue distribution of chronic wasting disease-associated prions in free-ranging Rocky Mountain elk


>>>Interestingly, five of fifteen sPMCA positive dams showed no evidence of PrPCWD in either CNS or LRS, sites typically assessed in diagnosing CWD. Analysis of fetal tissues harvested from the fifteen sPMCA positive dams revealed PrPCWD in 80% of fetuses (12/15), regardless of gestational stage. These findings demonstrate that PrPCWD is more abundant in peripheral tissues of CWD exposed elk than current diagnostic methods suggest, and that transmission of prions from mother to offspring may contribute to the efficient transmission of the CWD in naturally exposed cervid populations.<<<



***S P O N T A N E O U S***S P O R A D I C***


spontaneous atypical BSE ???


if that's the case, then France is having one hell of an epidemic of atypical BSE, probably why they stopped testing for BSE, problem solved $$$


As of December 2011, around 60 atypical BSE cases have currently been reported in 13 countries, *** with over one third in France.



so 20 cases of atypical BSE in France, compared to the remaining 40 cases in the remaining 12 Countries, divided by the remaining 12 Countries, about 3+ cases per country, besides Frances 20 cases. you cannot explain this away with any spontaneous BSe. ...TSS


Sunday, October 5, 2014


France stops BSE testing for Mad Cow Disease



*** spontaneous TSE prion, that's wishful thinking. on the other hand, if spontaneous did ever happen (never once documented in the field), it would be our worst nightmare, due to feed. just saying.


*** We describe the transmission of spongiform encephalopathy in a non-human primate inoculated 10 years earlier with a strain of sheep c-scrapie. Because of this extended incubation period in a facility in which other prion diseases are under study, we are obliged to consider two alternative possibilities that might explain its occurrence. We first considered the possibility of a sporadic origin (like CJD in humans). Such an event is extremely improbable because the inoculated animal was 14 years old when the clinical signs appeared, i.e. about 40% through the expected natural lifetime of this species, compared to a peak age incidence of 60–65 years in human sporadic CJD, or about 80% through their expected lifetimes. ***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.***


***>>> 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. <<<***










Zoonotic Potential of CWD Prions


Liuting Qing1, Ignazio Cali1,2, Jue Yuan1, Shenghai Huang3, Diane Kofskey1, Pierluigi Gambetti1, Wenquan Zou1, Qingzhong Kong1 1Case Western Reserve University, Cleveland, Ohio, USA, 2Second University of Naples, Naples, Italy, 3Encore Health Resources, Houston, Texas, USA


***These results indicate that the CWD prion has the potential to infect human CNS and peripheral lymphoid tissues and that there might be asymptomatic human carriers of CWD infection.***


P.105: RT-QuIC models trans-species prion transmission


Kristen Davenport, Davin Henderson, Candace Mathiason, and Edward Hoover Prion Research Center; Colorado State University; Fort Collins, CO USA


Additionally, human rPrP was competent for conversion by CWD and fCWD.


***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.***



From: Terry S. Singeltary Sr.


Sent: Saturday, November 15, 2014 9:29 PM


To: Terry S. Singeltary Sr.










*** 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). (SEE LINK IN REPORT HERE...TSS) PLUS, THE CDC DID NOT PUT THIS WARNING OUT FOR THE WELL BEING OF THE DEER AND ELK ;





*** 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).***



*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies.



now, let’s see what the authors said about this casual link, personal communications years ago. 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”


From: TSS (




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




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


-----Original Message-----


From: Sent: Sunday, September 29, 2002 10:15 AM


To:;; ebb8@CDC.GOV




Sunday, November 10, 2002 6:26 PM ......snip........end..............TSS


Thursday, April 03, 2008


A prion disease of cervids: Chronic wasting disease 2008 1: Vet Res. 2008 Apr 3;39(4):41 A prion disease of cervids: Chronic wasting disease Sigurdson CJ.




*** twenty-seven CJD patients who regularly consumed venison were reported to the Surveillance Center***,


snip... full text ;



July's Milwaukee Journal Sentinel article did prod state officials to ask CDC to investigate the cases of the three men who shared wild game feasts. The two men the CDC is still investigating were 55 and 66 years old. But there's also Kevin Boss, a Minnesota hunter who ate Barron County venison and died of CJD at 41. And there's Jeff Schwan, whose Michigan Tech fraternity brothers used to bring venison sausage back to the frat house. His mother, Terry, says that in May 2001, Jeff, 26, began complaining about his vision. A friend noticed misspellings in his e-mail, which was totally unlike him. Jeff began losing weight. He became irritable and withdrawn. By the end of June, he couldn't remember the four-digit code to open the garage door or when and how to feed his parents' cats. At a family gathering in July, he stuck to his parents and girlfriend, barely talking. "On the night we took him to the hospital, he was speaking like he was drunk or high and I noticed his pupils were so dilated I couldn't see the irises," his mother says. By then, Jeff was no longer able to do even simple things on his computer at work, and "in the hospital, he couldn't drink enough water." When he died on September 27, 2001, an autopsy confirmed he had sporadic CJD.


In 2000, Belay looked into three CJD cases reported by The Denver Post, two hunters who ate meat from animals killed in Wyoming and the daughter of a hunter who ate venison from a plant that processed Colorado elk. All three died of CJD before they were 30 years old. The CDC asked the USDA to kill 1,000 deer and elk in the area where the men hunted. Belay and others reported their findings in the Archives of Neurology, writing that although "circumstances suggested a link between the three cases and chronic wasting disease, they could find no 'causal' link." Which means, says Belay, "not a single one of those 1,000 deer tested positive for CWD. For all we know, these cases may be CWD. What we have now doesn't indicate a connection. That's reassuring, but it would be wrong to say it will never happen."


So far, says NIH researcher Race, the two Wisconsin cases pinpointed by the newspaper look like spontaneous CJD. "But we don't know how CWD would look in human brains. It probably would look like some garden-variety sporadic CJD." What the CDC will do with these cases and four others (three from Colorado and Schwan from Upper Michigan), Race says, is "sequence the prion protein from these people, inject it into mice and wait to see what the disease looks like in their brains. That will take two years."


CJD is so rare in people under age 30, one case in a billion (leaving out medical mishaps), that four cases under 30 is "very high," says Colorado neurologist Bosque. "Then, if you add these other two from Wisconsin [cases in the newspaper], six cases of CJD in people associated with venison is very, very high." Only now, with Mary Riley, there are at least seven, and possibly eight, with Steve, her dining companion. "It's not critical mass that matters," however, Belay says. "One case would do it for me." The chance that two people who know each other would both contact CJD, like the two Wisconsin sportsmen, is so unlikely, experts say, it would happen only once in 140 years.


Given the incubation period for TSEs in humans, it may require another generation to write the final chapter on CWD in Wisconsin. "Does chronic wasting disease pass into humans? We'll be able to answer that in 2022," says Race. Meanwhile, the state has become part of an immense experiment.



I urge everyone to watch this video closely...terry


*** you can see video here and interview with Jeff's Mom, and scientist telling you to test everything and potential risk factors for humans ***



O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations


Emmanuel Comoy, Jacqueline Mikol, Val erie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France


Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases). Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods. *** 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 longe 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. We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.




***thus questioning the origin of human sporadic cases...TSS





Transmission of Creutzfeldt-Jakob disease to a chimpanzee by electrodes contaminated during neurosurgery.


Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC. Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.


Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.



Tuesday, May 26, 2015


*** Minimise transmission risk of CJD and vCJD in healthcare settings ***


Last updated 15 May 2015




*** Creutzfeldt-Jakob Disease *** Public Health Crisis VIDEO




Diagnosis and Reporting of Creutzfeldt-Jakob Disease


Singeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA


Diagnosis and Reporting of Creutzfeldt-Jakob Disease


To the Editor: In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.


Terry S. Singeltary, Sr Bacliff, Tex


1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323.




cwd to humans, consumption, exposure, sub-clinical, iatrogenic, what if ?


Sunday, August 23, 2015


TAHC Chronic Wasting Disease CWD TSE Prion and how to put lipstick on a pig and take her to the dance in Texas


from the other side of the fence... today’s Singeltary Sunday School class ‘thinking outside of the box, God’s Wrath’ at the bottom. ...tss





Tuesday, August 11, 2015


Wisconsin doing what it does best, procrastinating about CWD yet again thanks to Governor Walker



Wednesday, March 18, 2015


*** Chronic Wasting Disease CWD Confirmed Texas Trans Pecos March 18, 2015



Wednesday, March 25, 2015


*** Chronic Wasting Disease CWD Cases Confirmed In New Mexico 2013 and 2014 UPDATE 2015



Wednesday, July 01, 2015


*** TEXAS Chronic Wasting Disease Detected in Medina County Captive Deer



Tuesday, July 21, 2015


*** Texas CWD Medina County Herd Investigation Update July 16, 2015 ***



Thursday, August 06, 2015





Friday, August 07, 2015


*** Texas CWD Captive, and then there were 4 ?



Thursday, September 24, 2015


TEXAS Hunters Asked to Submit Samples for Chronic Wasting Disease CWD TSE Prion Testing


*** I cannot stress enough to all of you, for the sake of your family and mine, before putting anything in the freezer, have those deer tested for CWD. ...terry



Saturday, October 03, 2015





Friday, October 09, 2015


Texas TWA Chronic Wasting Disease TSE Prion Webinars and Meeting October 2015



Monday, August 24, 2015


Ohio wildlife officials ramp up fight against fatal deer brain disease after 17 more positive tests CWD



Sunday, October 18, 2015


*** Pennsylvania Game Commission Law and Law Makers CWD TSE PRION Bans Singeltary 2002 from speaking A smelly situation UPDATED 2015



Monday, August 31, 2015


Illinois Loosing Ground to Chronic Wasting Disease CWD cases mounting with 71 confirmed in 2015 and 538 confirmed cases to date



Saturday, September 05, 2015


Missouri Captive Cervid Industry, CWD TSE Prion, and Procrastinating for Money, while mad deer and elk disease silently spreads



Friday, August 14, 2015


*** Susceptibility of cattle to the agent of chronic wasting disease from elk after intracranial inoculation



Friday, August 14, 2015


Carcass Management During a Mass Animal Health Emergency Draft Programmatic Environmental Impact Statement—August 2015



Tuesday, September 22, 2015


*** Host Determinants of Prion Strain Diversity Independent of Prion Protein Genotype



Friday, August 28, 2015


Chronic Wasting Disease CWD TSE Prion Diagnostics and subclinical infection




Sunday, October 18, 2015


*** World Organisation for Animal Health (OIE) and the Institut Pasteur Cooperating on animal disease and zoonosis research ***



just made a promise to mom DOD 12/14/97 confirmed hvCJD. never forget, and never let them forget. ...


Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518


Galveston Bay, on the bottom...


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