Sunday, September 13, 2015

urine, feces, and chronic wasting disease cwd tse prion risk factors, loading up the environment

Keystone Journal of Undergraduate Research 2(1): 1-7. 2014 1Corresponding author:


Detection of Urine-Based Deer Lures to Mitigate CWD Transmission in Pennsylvania


Kenneth Strauser Faculty Mentor: 1Dr. Aaron Haines Department of Biology Millersville University




The Pennsylvania Game Commission contacted Millersville University to perform tests to help combat the transmission and spread of Chronic Wasting Disease (CWD) via better detection of urine-based deer lures. The objective of this study was to use multiple methods and kits designed for detection of urine and blood to determine the best method of detection for urine-based deer lures. Methods included use of kits such as Uritrace®, Nite-SiteTM luminol, Hemascein® and Ultra-violet (UV) light. We found that no one technique yielded a positive for all urine-based deer lures. The UV light and Uritrace methods were the most effective and the UV light was the best technique in field-testing. The spread of CWD throughout the Commonwealth has been confirmed and these findings provide a foundation to further develop methods to detect urine-based deer lures to help mitigate the spread of CWD.




An executive order given by the Pennsylvania Game Commission established several restrictions within the DMA, one of which was the prohibition of the possession and use of deer urine (Pennsylvania Game Commission 2013). Urine-based deer lures are used by white-tailed deer hunters to attract deer into designated areas for harvest. It is estimated that between 10 and 40% of Pennsylvania hunters have used urine-based deer lures to hunt deer (Pennsylvania Game Commission 2013). At the same time, commercial urine-based deer lures to attract white–tailed deer have become readily available to consumers at common retail sporting goods stores such as Wal-Mart, Bass Pro Shops, and Cabela’s. However, urineStrauser - Urine-Based Deer Lures and CWD 2 based deer lures have been known to be collected from domestic white-tailed deer herds, with the potential of an animal infected with CWD residing within the herd. This can lead to the risk of CWD infecting wild populations of white-tailed deer via hunter use of deer lures. Thus, the use of urine-based deer lures is prohibited within the DMA (Pennsylvania Game Commission 2013).


Due to this risk, the Pennsylvania Game Commission contacted Millersville University to investigate if urine-based deer lures can be identified in the field using forensic tests. Based on a review of scientific literature and a lack of published reports, we know of no other study that has conducted these types of tests. The objective of this study was to determine if there were reliable field based tests to detect urine-based deer lures. The Pennsylvania Game Commission could then use these tests as part of a CWD prevention strategy in Pennsylvania. Our null hypothesis was that none of our forensics tests would be able to detect the presence of urine-based deer lures.






We rejected our null hypothesis that none of the tests would yield a positive result for detecting urine-based deer lures. However, our tentative results suggest that each test has limitations in regards to detecting urine-based lures. The most promise in results was provided by the UV tests. However, we found Strauser - Urine-Based Deer Lures and CWD that urine-based lures using UV could not be detected in certain fabrics like leather and treated cotton shirts, but could be seen under UV light on solid ground surfaces (i.e., leaves, sticks) and on untreated cotton and shoe foam. A combination of methods (sight, smell, UV, identification of key wicks, and Uritrace® for those which yielded a positive) could be helpful to detect presence of most of these lures, whether on scrapes or on the different fabric material which tested positive. We are hopeful that the knowledge gained from these tests provides insight into better techniques to detect urine-based deer lures to help mitigate the spread of CWD throughout Pennsylvania.


Some commercial lures were collected from individual deer (Code Blue® Scrape Mate, Code Blue® Buck, Code Blue® Doe) and stated on their bottles that the urine will smell like a “real, single deer” and give a “true-tolife hunting experience”. On the back of the three Wildlife Research Center® products, a guarantee stated that the urine types were sourced from deer tested for (and free of) CWD. However, the only way to ensure that a deer is free of CWD is to test its brain tissue, which would require the deer to be deceased (Williams et al. 2002). In addition, the maximum disease course for CWD (time from exposure to end-stage clinical disease) is not known, but can exceed 25 months in experimentally infected deer (Williams et al. 2002).


***Therefore, we recommend that the Pennsylvania Game Commission should continue to ban urine-based deer lures on Pennsylvania DMAs.


Keywords: Chronic Wasting Disease; detection; urine-based lure; white-tailed deer



Prion Amplification and Hierarchical Bayesian Modeling Refine Detection of Prion Infection


A. Christy Wyckoff1, 2 n1 , Nathan Galloway3 n1 , Crystal Meyerett-Reid1 , Jenny Powers4 , Terry Spraker1 , Ryan J. Monello4 , Bruce Pulford1 , Margaret Wild4 , Michael Antolin3 , Kurt VerCauteren2 […] & Mark Zabel1 - Show fewer authors Scientific Reports 5, Article number: 8358 (2015) doi:10.1038/srep08358 Download Citation


Molecular ecology | Proteins | Statistics Received: 27 June 2014 Accepted: 19 January 2015 Published online: 10 February 2015


Prions are unique infectious agents that replicate without a genome and cause neurodegenerative diseases that include chronic wasting disease (CWD) of cervids. Immunohistochemistry (IHC) is currently considered the gold standard for diagnosis of a prion infection but may be insensitive to early or sub-clinical CWD that are important to understanding CWD transmission and ecology. We assessed the potential of serial protein misfolding cyclic amplification (sPMCA) to improve detection of CWD prior to the onset of clinical signs. We analyzed tissue samples from free-ranging Rocky Mountain elk (Cervus elaphus nelsoni) and used hierarchical Bayesian analysis to estimate the specificity and sensitivity of IHC and sPMCA conditional on simultaneously estimated disease states. Sensitivity estimates were higher for sPMCA (99.51%, credible interval (CI) 97.15–100%) than IHC of obex (brain stem, 76.56%, CI 57.00–91.46%) or retropharyngeal lymph node (90.06%, CI 74.13–98.70%) tissues, or both (98.99%, CI 90.01–100%). Our hierarchical Bayesian model predicts the prevalence of prion infection in this elk population to be 18.90% (CI 15.50–32.72%), compared to previous estimates of 12.90%. Our data reveal a previously unidentified sub-clinical prion-positive portion of the elk population that could represent silent carriers capable of significantly impacting CWD ecology.




Infected animals shed prions into the environment through saliva, feces, urine and even antler velvet15,20,21,22,23,24. Studies have successfully transmitted PrPCWD through a single dose of urine or feces from animals displaying signs of CWD, indicating that at the time of clinical disease sufficient prions are shed to result in an infectious dose24,25. However, at what stage(s) of disease animals shed prions into the environment remains unclear. If shedding occurs early in disease, a sub-clinical animal may not only shed prions into the environment, increasing the infectious reservoir, but may also transmit CWD horizontally to their associates. Unfortunately little is known about the prevalence of early or sub-clinical infection, and what role they may play in CWD transmission ecology. This ignorance raises a critical question that must be answered: how long do free-ranging animals live once infected? Answering it requires detection of prion infections as early as possible in the course of infection.




Our results suggest that prevalence of prion infection in this free-ranging RMNP elk herd is much higher than previously reported. Prior to 2013, the CWD prevalence in elk surrounding RMNP was estimated at <2 12.9="" 18.90="" 2008="" 2013="" 28="" 4="" adult="" al.="" all="" an="" and="" animals="" based="" biopsy="" by="" can="" cases="" conclude="" conservatively="" consistent="" course="" cwd="" detect="" div="" during="" early="" elk="" estimated="" et="" female="" finding="" found="" from="" here="" higher="" ihc="" in="" infected="" infection="" known="" model="" monello="" of="" on="" our="" over="" overall="" population.="" positive="" prevalence="" previous="" prpcwd="" ramalt19="" ramalt="" removed="" report="" reported="" reports.="" rmnp="" sample="" since="" spmca="" study.="" tested="" than="" that="" the="" their="" three-year="" times="" we="" were="" which="" who="" with="">

The higher overall prevalence estimate in this herd suggests previous measurements have been missing a large portion of PrPCWD -positive animals and that a long history of exposure to prions and decades of relatively high densities on the winter range may have led to increased prevalence19,42,43. Further study is required to identify possible ecological differences in this herd compared to neighboring ones.


As an amplifying assay, sPMCA has previously been shown to be extremely specific and sensitive in prion detection studies19,22,40,44,45 but had not been directly compared to IHC in elk or in samples from free-ranging animals. This study has shown that sPMCA on the obex alone is more sensitive than IHC on obex or RPLN. sPMCA also detected several positive obex samples, which were IHC-negative from 2011. We argue that this increased detection represents early stage infections or sub-clinical animals, which may or may not shed PrPCWD or develop clinical disease at a later time point.


Similar to Monello et al.19, our sensitivity analysis of IHC by tissue indicates that in this study population, that IHC in the RPLN was actually more effective in detecting positives animals than the obex. These results indicate that IHC on the obex might not be the best method to detect nascent PrPCWD in elk, and perhaps the premise that the infection course is different between deer and elk is not absolute. Determining whether sPMCA in the RPLN would show a similar improvement on sensitivity compared to obex requires further study.


Our data demonstrate that previous IHC-based studies are possibly missing early stage or sub-clinical cases in sampled populations. It is widely accepted that IHC is sensitive enough to detect pre-clinical cases, but we propose that sPMCA can detect additional cases even earlier, possibly soon after infection. In previous work we found sPMCA had a detection limit of 10−9 35,46 which is much more sensitive than the sensitivity of a mouse bioassay at 10−4. This suggests that animals found positive by sPMCA have much lower levels of PrPCWD than animals with clinical disease, but are indeed infected. The detection of very early sub-clinical cases raises the question of biological relevance at the population level. We propose that this sub-clinical subset of the population may be ecologically important to the disease transmission cycle because of potential preclinical vertical transmission from mother to offspring47, horizontal transmission through direct contact, or indirect transmission through environmental deposits of prions.


It remains unclear when animals begin shedding prions into the environment. Through the use of a mouse bioassay Tamguney et al.22,24,44,45 showed asymptomatic deer were capable of shedding infectious levels of CWD as early as 10 months prior to clinical disease. Bioassays, both in mice and deer, have limited sensitivity so shedding could be occurring much earlier than 10 months post-infection but at levels insufficient to cause clinical disease in the infected host. It is also unclear if genotype plays a role in prion shedding, as well as disease course. Our data suggest that having at least one L allele at codon 132 does not alter the disease prevalence within the ML genotype, supporting data reported by Perucchini et al.27. The slow disease course and the potential existence of a carrier state facilitate a high prevalence and frequent opportunity for transmission between animals with the MM and ML genotypes.


It is commonly stated in the literature that CWD is an invariably fatal disease, but it may be more accurate to state that once animals begin to show clinical signs they are certain to succumb to CWD or other associated causes of death such as predation4,24,48. Perhaps other carrier states exist within the population, which may or may not contribute to the transmission and deposition of prions in the population and the environment. Further research is required to address the role of a carrier state in the ecology of CWD transmission.


The application of sPMCA will be important both to research and for diagnostic investigation, and may improve state and federal surveillance programs for CWD in both naïve and endemic host populations. Increased sensitivity, and the need for only obex tissue, may lead to detection of new focal points prior to clinical disease emerging in otherwise CWD-free populations. Additionally, in the economically and politically difficult scenario of culling captive herds that tested positive for CWD, extremely sensitive assays such as sPMCA of prions from tissue and excreta are essential to verify that more animals besides the index case were infected, and if any sub-clinical carriers may have been shedding into the environment.


Overall, our data contribute to the increasing evidence that a portion of a herd may be infected, but die from other causes while infected with PrPCWD because of age, genetic susceptibility or other unknown factors. However, the contribution of prions shed into the environment from this sub-clinical population may be important and requires further investigation. The existence of an infectious PrPCWD carrier state aligns with disease ecology theory, which proposes balance between transmissibility and pathogenesis of a pathogen. As such, through selection pressures from the host and external environment the pathogen will tend towards the greatest transmissibility strategy. CWD transmission may be more complicated than disease ecology might predict, since prolonged persistence and indirect transmission of prions in the environment may potentiate spread without affecting pathogenesis.


Despite the fact that prions are only protein, studies continue to point at evolutionary behavior and selection pressures of prions which indicate that like other pathogens, prions are capable of evolving and adapting to their environment4,27,48,49. With increasing prevalence at the population level, as is reported in this study, sPMCA will continue to be an important tool to investigate CWD in wildlife.



Quantitative assessment of prion infectivity in tissues and body fluids by real-time quaking-induced conversion


Authors: Davin M. Henderson1, Kristen A. Davenport1, Nicholas J. Haley2, Nathaniel D. Denkers1, Candace K. Mathiason1, Edward A. Hoover1


VIEW AFFILIATIONS Affiliations: 1 1Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA 2 2Department of Diagnostic Medicine and Pathobiology, Kansas State University, College of Veterinary Medicine, Manhattan, KS 66506, USA Correspondence Edward A. Hoover J. Gen. Virol., January 2015 96: 210-219, doi: 10.1099/vir.0.069906-0 Subject: TSE Agents Received: 08/07/2014 Accepted: 06/10/2014 Published Online: 01/01/2015


 Prions are amyloid-forming proteins that cause transmissible spongiform encephalopathies through a process involving the templated conversion of the normal cellular prion protein (PrPC) to a pathogenic misfolded conformation. Templated conversion has been modelled in several in vitro assays, including serial protein misfolding amplification, amyloid seeding and real-time quaking-induced conversion (RT-QuIC). As RT-QuIC measures formation of amyloid fibrils in real-time, it can be used to estimate the rate of seeded conversion. Here, we used samples from deer infected with chronic wasting disease (CWD) in RT-QuIC to show that serial dilution of prion seed was linearly related to the rate of amyloid formation over a range of 10−3 to 10−8 µg. We then used an amyloid formation rate standard curve derived from a bioassayed reference sample (CWD+ brain homogenate) to estimate the prion seed concentration and infectivity in tissues, body fluids and excreta. Using these methods, we estimated that urine and saliva from CWD-infected deer both contained 1–5 LD50 per 10 ml. Thus, over the 1–2 year course of an infection, a substantial environmental reservoir of CWD prion contamination accumulates.



Research Article


Detection of CWD Prions in Urine and Saliva of Deer by Transgenic Mouse Bioassay


Nicholas J. Haley, Davis M. Seelig, Mark D. Zabel, Glenn C. Telling, Edward A. Hoover


Published: March 18, 2009 DOI: 10.1371/journal.pone.0004848


 Abstract Chronic wasting disease (CWD) is a prion disease affecting captive and free-ranging cervids (e.g. deer, elk, and moose). The mechanisms of CWD transmission are poorly understood, though bodily fluids are thought to play an important role. Here we report the presence of infectious prions in the urine and saliva of deer with chronic wasting disease (CWD). Prion infectivity was detected by bioassay of concentrated, dialyzed urine and saliva in transgenic mice expressing the cervid PrP gene (Tg[CerPrP] mice). In addition, PrPCWD was detected in pooled and concentrated urine by protein misfolding cyclic amplification (PMCA). The concentration of abnormal prion protein in bodily fluids was very low, as indicated by: undetectable PrPCWD levels by traditional assays (western blot, ELISA) and prolonged incubation periods and incomplete TSE attack rates in inoculated Tg(CerPrP) mice (373±3days in 2 of 9 urine-inoculated mice and 342±109 days in 8 of 9 saliva-inoculated mice). These findings help extend our understanding of CWD prion shedding and transmission and portend the detection of infectious prions in body fluids in other prion infections.




While our findings point to urine as an additional vehicle for CWD transmission, only 2 of 9 inoculated tg1536 mice were confirmed WB/IHC-positive for prion infection, with a third PrPCWD+ animal later identified by PMCA. This contrasts with 8 of 9 positive mice receiving saliva and infers a much lower concentration of prion infectivity in urine. The wide range of survival times in inoculated mice suggests relatively low levels of infectious prions and/or uneven distribution of infectious PrP moieties in the inocula [21]. Differing [CerPrP] zygosity in tg1536 mice (homozygous vs. hemizygous) may also have played a role in this variation.


Using sPMCA, PrPCWD was repeatedly identified in test urine and spiked urine and saliva used as positive control, but was not detected in test saliva after three rounds of amplification. The reasons for our inability to identify PrPCWD in saliva – given the definitive bioassay findings – remain unknown, and we propose the presence of as-yet unidentified inhibitors such as mucin or salivary proteases which are thought to negatively affect other in vitro assays [22], [23].


The finding of PrPCWD in urine and saliva calls for the identification of the pathological processes and cellular associations of the prion protein involved in shedding. Previous studies have related renal pathology to prionuria [24], [25], a finding which corresponds to our identification of mild to moderate nephritis in those deer providing samples for the current study. It is plausible that renal pathology contributed to prionuria in each of these animals; as samples were pooled, however, we cannot identify specific animals in which it may have been occurring, nor can we accurately estimate the relative level of prionuria occurring in each donor as ultrastructural studies were not performed [26]. While we have not yet identified pathologic prions in renal source tissues [Unpublished data], protease-resistant PrPCWD has been identified by immunostaining in renal tissue of prion-infected deer [27], sheep [28], hamsters and most intriguingly humans [29], foreshadowing the potential for prionuria in other transmissible spongiform encephalopathies. We continue to examine tissues from CWD+ deer in an effort to determine the pathogenesis and kinetics of CWD prion excretion and shedding.


Evidence for excretion and shedding of infectious prions is also accumulating in the scrapie system. PrPC-converting activity has been identified by sPMCA in the urine of scrapie-infected sheep, hamsters and mice [21], [30], [31], [32]. Prion infectivity has also been demonstrated in the feces of hamsters orally infected with scrapie [33]. Other studies point to infectious prions in the milk of scrapie-infected ewes [34], [35]. As noted above, it remains unknown whether other prion diseases (e.g. Kuru, BSE, CJD, TME) may be transmitted by bodily fluids or excreta other than blood. Additional studies examining feces, milk, and other body fluids are therefore necessary in CWD and other prion diseases, studies currently underway in our laboratory.


As CWD transmission may model communicability of other TSE's, the transmissible nature of prion diseases may serve as a model for other protein-misfolding diseases. For example, feces, but not urine, from both mice and cheetahs affected with systemic amyloidosis A (SAA) was recently shown to induce SAA in a mouse model, although negative controls were not available in those studies [36]. In light of the prionuria detected in CWD and in models of scrapie, further investigations of infectivity in body fluids in other protein folding diseases may be warranted in the event that prion diseases are not the only infectious proteinopathies.


In summary, we confirm prionsialia in CWD-affected deer by bioassay in cervidized mice and demonstrate for the first time infectious prions in the urine of these cervids by both bioassay and sPMCA. We are currently evaluating urine and saliva from individual animals in hopes of identifying predisposing factors, such as genotypic background and underlying pathology, which may contribute to prionuria and prionsialia. Concurrently, we have begun to explore the tissue origins and protease sensitivity of the infectious prions as well as the onset and duration of shedding in these bodily fluids.





Detection of CWD prion in fecal samples by RT-QuIC


Yo Ching Cheng1, Theodore Ralph John2, Sampson Law3, Stephanie Czub4, Sabine Gilch1


1Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada, 2Department of Molecular Biology, University of Wyoming, Laramie, Wyoming, USA, 3Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada, 4Canadian Food Inspection Agency (CFIA) Lethbridge Laboratory, Lethbridge, Alberta, Canada


Chronic wasting disease (CWD) is a prion disease which mainly affects captive and wild cervids in North America. To date, cases in elk, mule deer, white-tailed deer and moose h a v e b e e n r e p o r t e d . I n C W D , infectious prions are transported from the CNS into a wide range of peripheral tissues, body fluids, excreta and eventually shed into the environment.


In order to detect the disease, the use of easily accessible specimens such as feces would be a practical way for prion detection. However, those excretions and secretions harbor relatively low concentrations of prions which challenge current diagnosis methods. In an earlier study, we demonstrated that CWD prions are detectable in urine collected from pre-symptomatic deer and in fecal extracts by real-time quaking-induced conversion assay (RT-QuIC). RT-QuIC employs minute amounts of PrPSc as a seed to initiate conformational transition of recombinant PrP (rPrP) by vigorous intermittent shaking.


In this study, we aim to improve the detection of CWD pions in fecal extracts by RT-QuIC, and to determine the shedding pattern in feces of elk which were challenged orally with CWD prions in an experimental study. We u s e d m e t h a n o l p r e c i p i t a t i o n , u l t r a c e n t r i f u g a t i o n a n d s o d i u m phosphotungstic acid (NaPTA) precipitation to purify and to concentrate CWD prions in feces. We found that NaPTA precipitation of fecal extracts dose not interfere with seeding activity, but increases the sensitivity of detection. Our data demonstrate that concentration and purification of PrPSc enhances detection of CWD prions in feces, which will eventually enable the use of RTQuIC for CWD surveillance.


Prion2015 Program Guide 27




Prion peripheralization is a host-driven trait of prion infection, independent of strain


Nicholas Haley1, Chris Siepker1, Sarena Olsen2, Glenn Telling2, Edward Hoover2, Justin Greenlee3, Juergen Richt1 1Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS, USA, 2Department of MIP, Colorado State University, Fort Collins, CO, USA, 3Virus and Prion Research Unit, National Animal Disease Center, ARS, USDA, Ames, IA, USA


Chronic wasting disease (CWD), like scrapie of sheep, is a horizontally transmissible spongiform encephalopathy. Proposed natural routes of transmission for both agents include saliva, urine, and feces, and are likely related to an accumulation of misfolded prion proteins in excretory tissues, including salivary glands and both gastrointestinal and urogenital tracts. In recent years, prion research has focused on the prion strain (e.g. bovine spongiform encephalopathy – BSE, scrapie, or CWD) as the source code for pathogenic information – encoded by tertiary conformation for example – with strain commonly used as the predominant criteria for classifying prions. In the present study, we compared the peripheral distribution of CWD prions in two experimental host species: transgenic cervidized mice and cattle. Following inoculation and demonstrable infection with CWD, a variety of central and peripheral tissues were collected at necropsy, including brain and both peripheral lymphoid and excretory tissues, and analyzed for prion seeding activity by real time quaking-induced conversion (RT-QuIC). While transgenic mice displayed broad and elevated levels of CWD prions in the periphery, as has been demonstrated with scrapie in mice and CWD in deer, the peripheralization of CWD prions in cattle was limited and similar to that reported in BSE. Our findings imply that prion peripheralization is likely a trait imparted by the host, independent of the prion strain, though additional research investigating the peripheralization of BSE prions in cervids, for example, is required. It also remains to be seen if other prion phenotypes, e.g. zoonotic potential, are hostderived in nature.



Longitudinal Detection of Prion Shedding in Saliva and Urine by CWD-Infected Deer by RT-QuIC


Davin M. Henderson1, Nathaniel D. Denkers1, Clare E. Hoover1, Nina Garbino1, Candace K. Mathiason1 and Edward A. Hoover1# + Author Affiliations


1Prion Research Center, Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523 ABSTRACT Chronic Wasting Disease (CWD) is an emergent, rapidly spreading prion disease of cervids. Shedding of infectious prions in saliva and urine is thought to be an important factor in CWD transmission. To help elucidate this issue, we applied an in vitro amplification assay to determine the onset, duration, and magnitude of prion shedding in longitudinally collected saliva and urine samples from CWD-exposed white-tailed deer. We detected prion shedding as early as 3 months after CWD exposure and sustained shedding throughout the disease course. We estimated that a 50% lethal dose (LD50) for cervidized transgenic mice would be contained in 1 ml of infected deer saliva or 10 ml or urine. Given the average course of infection and daily production of these body fluids, an infected deer would shed thousands of prion infectious dosesover the course of CWD infection. The direct and indirect environmental impact of this magnitude of prion shedding for cervid and non-cervid species is surely significant.


Importance: Chronic wasting disease (CWD) is an emerging and uniformly fatal prion disease affecting free ranging deer and elk and now recognized in 22 United States and 2 C anadian Provinces. It is unique among prion diseases in that it is transmitted naturally though wild populations. A major hypothesis for CWD's florid spread is that prions are shed in excreta and transmitted via direct or indirect environmental contact. Here we use a rapid in vitro assay to show that infectious doses of CWD prions are in fact shed throughout the multi-year disease course in deer. This finding is an important advance in assessing the risks posed by shed CWD prions to animals as well as humans.




↵#To whom correspondence should be addressed: Edward A. Hoover, Prion Research Center, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, US Email:



Longitudinal Detection of Prion Shedding in Saliva and Urine by Chronic Wasting Disease-Infected Deer by Real-Time Quaking-Induced Conversion


Davin M. Henderson, Nathaniel D. Denkers, Clare E. Hoover, Nina Garbino, Candace K. Mathiason and Edward A. Hoover


K. L. Beemon, Editor


+ Author Affiliations




Chronic wasting disease (CWD) is an emergent, rapidly spreading prion disease of cervids. Shedding of infectious prions in saliva and urine is thought to be an important factor in CWD transmission. To help to elucidate this issue, we applied an in vitro amplification assay to determine the onset, duration, and magnitude of prion shedding in longitudinally collected saliva and urine samples from CWD-exposed white-tailed deer. We detected prion shedding as early as 3 months after CWD exposure and sustained shedding throughout the disease course. We estimated that the 50% lethal dose (LD50) for cervidized transgenic mice would be contained in 1 ml of infected deer saliva or 10 ml of urine. Given the average course of infection and daily production of these body fluids, an infected deer would shed thousands of prion infectious doses over the course of CWD infection. The direct and indirect environmental impacts of this magnitude of prion shedding on cervid and noncervid species are surely significant.


IMPORTANCE Chronic wasting disease (CWD) is an emerging and uniformly fatal prion disease affecting free-ranging deer and elk and is now recognized in 22 U.S. states and 2 Canadian provinces. It is unique among prion diseases in that it is transmitted naturally through wild populations. A major hypothesis to explain CWD's florid spread is that prions are shed in excreta and transmitted via direct or indirect environmental contact. Here we use a rapid in vitro assay to show that infectious doses of CWD prions are in fact shed throughout the multiyear disease course in deer. This finding is an important advance in assessing the risks posed by shed CWD prions to animals as well as humans.


FOOTNOTES Received 14 May 2015. Accepted 23 June 2015. Accepted manuscript posted online 1 July 2015. Address correspondence to Edward A. Hoover,


D.M.H. and N.D.D. contributed equally to this article.


Citation Henderson DM, Denkers ND, Hoover CE, Garbino N, Mathiason CK, Hoover EA. 2015. Longitudinal detection of prion shedding in saliva and urine by chronic wasting disease-infected deer by real-time quaking-induced conversion. J Virol 89:9338–9347. doi:10.1128/JVI.01118-15.



Insights into Chronic Wasting Disease and Bovine Spongiform Encephalopathy Species Barriers by Use of Real-Time Conversion


Kristen A. Davenport, Davin M. Henderson, Jifeng Bian, Glenn C. Telling, Candace K. Mathiason and Edward A. Hoover Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA


K. L. Beemon, Editor


+ Author Affiliations




The propensity for transspecies prion transmission is related to the structural characteristics of the enciphering and new host PrP, although the exact mechanism remains incompletely understood. The effects of variability in prion protein on cross-species prion transmission have been studied with animal bioassays, but the influence of prion protein structure versus that of host cofactors (e.g., cellular constituents, trafficking, and innate immune interactions) remains difficult to dissect. To isolate the effects of protein-protein interactions on transspecies conversion, we used recombinant PrPC and real-time quaking-induced conversion (RT-QuIC) and compared chronic wasting disease (CWD) and classical bovine spongiform encephalopathy (cBSE) prions. To assess the impact of transmission to a new species, we studied feline CWD (fCWD) and feline BSE (i.e., feline spongiform encephalopathy [FSE]). We cross-seeded fCWD and FSE into each species' full-length, recombinant PrPC and measured the time required for conversion to the amyloid (PrPRes) form, which we describe here as the rate of amyloid conversion. These studies revealed the following: (i) CWD and BSE seeded their homologous species' PrP best; (ii) fCWD was a more efficient seed for feline rPrP than for white-tailed deer rPrP; (iii) conversely, FSE more efficiently converted bovine than feline rPrP; (iv) and CWD, fCWD, BSE, and FSE all converted human rPrP, although not as efficiently as homologous sCJD prions. These results suggest that (i) at the level of protein-protein interactions, CWD adapts to a new species more readily than does BSE and (ii) the barrier preventing transmission of CWD to humans may be less robust than estimated.


IMPORTANCE We demonstrate that bovine spongiform encephalopathy prions maintain their transspecies conversion characteristics upon passage to cats but that chronic wasting disease prions adapt to the cat and are distinguishable from the original prion. Additionally, we showed that chronic wasting disease prions are effective at seeding the conversion of normal human prion protein to an amyloid conformation, perhaps the first step in crossing the species barrier.


FOOTNOTES Received 3 June 2015. Accepted 1 July 2015. Accepted manuscript posted online 8 July 2015. Address correspondence to Edward A. Hoover,


Citation Davenport KA, Henderson DM, Bian J, Telling GC, Mathiason CK, Hoover EA. 2015. Insights into chronic wasting disease and bovine spongiform encephalopathy species barriers by use of real-time conversion. J Virol 89:9524–9531. doi:10.1128/JVI.01439-15.





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 soil ;








I7 Early Trafficking and Dissemination of CWD Prions in Deer


Edward A. Hoover1*, Clare E. Hoover1, Davin M. Henderson1, Nathaniel D. Denkers1, Kristin A. Davenport1, Shannon Bartelt-Hunt2, Alan M. Elder1, Anthony E. Kincaid3, 4, Jason C. Bartz3, Mark D. Zabel1, Candace K. Mathiason1


1Prion Research Center, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA 2Department of Civil Engineering, University of Nebraska-Lincoln, Prion2015 Program Guide


10 invited speakers PRION 2015 Omaha, Nebraska, USA, 3Department of Medical Microbiology and immunology Creighton University, Omaha, Nebraska, USA 4Department of Pharmacy Science, Creighton University, Omaha, Nebraska, USA


* P r e s e n t i n g a u t h o r ’ s e - m a i l :


Efficient horizontal infection is a hallmark of chronic wasting disease (CWD) in freeranging cervids. The mechanisms and pathways that enable this remarkable process, however, remain incompletely understood--in particular the facile transmucosal entry, exit, and environmental persistence of CWD prions. We have focused on trans-mucosal CWD infection in white-tailed deer, specifically on early prion tissue tropism and later stage prion shedding and association with environmental constituents using modifications of real-time quaking-induced conversion combined with amplified immunohistochemistry. We have documented very early trans-mucosal prion passage (within hours), followed by uptake and amplification in upper digestive tract lymphoid t i s s u e s ( 4 w e e k s ) , and dissemination to more distant lymphoid and non-lymphoid tissue sites (8-12 weeks). We have used quantitative approaches to realtime conversion to estimate the relatively low (i.e. vs. tissues) prion concentrations in body fluids and excreta; i.e. >100 (cervidized mouse) LD50 are shed daily in the urine of one CWD infected deer. Using similar methods, we have also demonstrated and quantified the impressive






Novel Detection of PrPCWD on Plants Collected from Rocky Mountain National Park


Aimee Ortega1, Jeffrey Seligman1, Jan Leach2, Mark Zabel1 1Colorado State University, Prion Research Center, Department of Microbiology, Immunology and Pathology, Fort Collins, CO, USA, 2Colorado State University, Department of Bioagricultural Sciences and Pest Management, Fort Collins, CO, USA


Chronic wasting disease (CWD) affects animals such as elk, deer, and moose and has become endemic over the last decade. The disease is one of many transmissible spongiform encephalopathies which occur due to the accumulation of an abnormally folded, proteinase K resistant, form of the normal cellular prion protein PrPC. This abnormally folded form, PrPCWD, seeds conversion of PrPC into PrPCWD and eventually forms amyloid fibrils. The exact mechanisms behind transmission and spread of CWD are unknown but research has shown that it can be spread through h o r i z o n t a l , v e r t i c a l , and i n d i r e c t / environmental routes. PrPCWD has been found in both soil and water. Additionally, PrPCWD is very resistant to degradation which makes it stable in the environment for long periods of time. A study has shown that the


Prion2015 Program Guide 29


abnormal prion protein can remain viable in the environment for as long as 16 years. We wanted to further explore the latter and determine whether prions could be detected in grasses and other plants in Rocky Mountain National Park (RMNP) by use of the protein misfolding cyclic amplification (PMCA) assay.


This past summer we surveyed three sites within RMNP and collected a total of 32 plants. Plants were collected from both outside and inside enclosures that serve to keep wildlife out and allow for restoration and regrowth of the flora. Plant samples were assayed by PMCA and we are now reporting for the first time the novel detection of PrPCWD from the surface on a number of plants assayed.


P195 Chronic wasting disease prions detected during early stages of infection by mbPMCA in tissues from white-tailed deer o r a l l y inoculated with f r e e and microparticle-bound prions


Alexandra Chesney1, Chad Johnson1, Tracy Nichols2, Hannah Kornely1, Dania Shoukfeh1, Joel Pedersen1


1University of Wisconsin, Madison, WI, USA, 2United States Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), Wildlife Services (WS), National Wildlife Research Center (NWRC), Fort Collins, CO, USA


Enhanced oral transmission of rodent a d a p t e d p r i o n d i s e a s e has been demonstrated with the disease agent bound to several types of mineral microparticles; however, the generalizability of this finding to ruminants has not been established. Contaminated soil is believed to represent a reservoir for environmental prions and may contribute to horizontal transmission of chronic wasting disease (CWD) in captive and wild cervid populations. Here, we examined the impact of CWD agent association with microparticles o f montmorillonite, an aluminosilicate clay mineral that showed the largest disease transmission enhancement in rodent bioassays, on early disease in orally inoculated white-tailed deer. Amplification of prions by PMCA has been achieved from various contaminated organs and excretions at late stages in disease. Using microplatebased PMCA (mbPMCA), we detected different accumulation patterns in white-tailed deer tissues 42 days after oral inoculation with CWD prions bound to montmorillonite. We expected mbPMCA to be more sensitive than immunohistochemistry (IHC) to determine prion accumulations in tissues. Through evaluation of mb-PMCA positive tissues, we found that mbPMCA is more sensitive than IHC by at least a factor of 106.3, and detected CWD prions in multiple tissue types that were negative by IHC. These findings suggest that microparticles can enhance the transmission of CWD in white-tailed deer and also demonstrates the consistency and high-throughput utility of the mbPMCA assay. Furthermore, our results indicate that enhanced transmission of microparticle-bound CWD agent warrants consideration in evaluating the relative importance o f d i r e c t and i n d i r e c t (environmental) transmission of CWD in natural populations and in disease management.


Prion2015 Program Guide 35



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.<<<



P.141: Abundant prion shedding in CWD-infected deer revealed by Realtime conversion


Edward A Hoover,1 Davin M Henderson,1 Nathaniel D Denkers,1 Candace K Mathiason,1 Matteo Manca,2,3 and Byron Caughey2 1Prion Research Center, Colorado State University; Fort Collins, CO USA; 2Laboratory of Persistent Viral Diseases, NI AID; Hamilton, MT USA; 3Department of Biomedical Sciences, University of Cagliari; Monserrato, Italy


Background/Introduction. Chronic wasting disease (CWD) is unique among prion diseases in its efficient lateral transmission in nature. While the presence of infectious prions in body fluids and excreta of infected cervids has been demonstrated by bioassay, the dynamics, magnitude, and consequences of prion shedding remain unknown. The present studies were undertaken to determine the kinetics, duration, and magnitude of prion shedding in infected white-tailed deer.


Materials and Methods. Longitudinal samples were collected from white-tailed deer over a 2-year span after either oral (n=11)] aerosol (n = 6) CWD exposure. The assay protocol employed phosphotungstic acid precipitation of either whole saliva or the pelleted fraction of urine to seed recombinant Syrian hamster prion PrP substrate in RT-QuIC reactions. Prion seeding activity was assayed in 8 replicates of each sample employing thioflavin T detection in a 96-well plate-based fluorometer. Prion seeding reaction rate was determined by taking the inverse of the time at which samples exceeded a threshold of 5 standard deviations above the mean fluorescence of negative controls (1/time to threshold). Seeding activity was quantitated by comparing the realtime conversion reaction rate to a standard curve derived from a reference bioassayed brain pool homogenate from deer with terminal CWD.


Results. We analyzed >200 longitudinally collected, blinded, then randomized saliva and urine samples from 17 CWDinfected and 3 uninfected white-tailed deer. We detected prion shedding as early as 3 months post exposure and sustained thereafter throughout the disease course in both aerosol and orally exposed deer. The incidence of non-specific false positive results from > 500 saliva and urine samples from negative control deer was 0.8%. By comparing real-time reaction rates for these body fluids to a bioassayed serially diluted brain control, we estimated that ≤1 ml of saliva or urine from pre-symptomatic infected deer constitutes a lethal infectious prion dose.


Conclusion. CWD prions are shed in saliva and urine of infected deer as early as 3 months post infection and throughout the subsequent >1.5 year course of infection. In current work we are examining the relationship of prionemia to excretion and the impact of excreted prion binding to surfaces and particulates in the environment.


Acknowledgments. Support: NIH-RO1-NS-061902; Morris Animal Foundation D12ZO-045


P.154: Urinary shedding of prions in Chronic Wasting Disease infected white-tailed deer


Nathaniel D Denkers,1 Davin M Henderson, 1 Candace K Mathiason,1 and Edward A Hoover1 1Prion Research Center, Department of Microbiology, Immunology, and Pathology, Colorado State University; Fort Collins, CO USA


Background/Introduction. Chronic wasting disease (CWD) is unique among prion diseases in its efficient lateral transmission in nature, yet the dynamics and magnitude of shedding and its immediate and long term consequences remain unknown. The present study was designed to determine the frequency and time span in which CWD prions are shed in urine from infected white-tailed deer using adapted real-time quaking-induced conversion (RT-QuIC) methodology.


Materials and Methods. Longitudinal urine samples were collected by free catch or catheterization over a 2-year period from oral-route infected [CWD+ (n = 11)] and aerosol-route-infected [CWD+ (n = 6); CWD- (n = 3)] white-tailed deer. High speed centrifugation pelleted material from 500 µl of urine was treated with sodium phosphotungstic acid (Na-PTA), resuspended in 0.05% SDS buffer, and used as seed in RT-QuIC assays employing recombinant Syrian hamster prion PrP substrate. Eight (8) replicates of each sample were run and prion seeding activity was recorded as thioflavin T binding fluorescence (480 nm emission) using a fluorimeter-shaker. Samples were considered positive if they crossed an established threshold (5 standard deviations above the negative mean fluorescence).


Results. In our oral-route inoculation studies, prion seeding activity has been demonstrated in urine collected at 6 months post-inoculation in 6 of 10 deer (11 of 80 replicates; 14%), and intermittently at later time points in all 11 CWD+ exposed deer. Our aerosol-route inoculation studies also showed prion seeding activity in urine collected at 6 months post-inoculation in 1 of 2 deer (3 of 16 replicates; 19%), and intermittently at later time points in 4 of 6 CWD+ exposed deer. Urine from sham-inoculated control deer and all baseline samples yielded 3 false-positive prion seeding activities (3 of 352 replicates; 0.8%).


Conclusion. CWD prions (as inferred by prion seeding activity by RT-QuIC) are shed in urine of infected deer as early as 6 months post inoculation and throughout the subsequent disease course. Further studies are in progress refining the real-time urinary prion assay sensitivity and we are examining more closely the excretion time frame, magnitude, and sample variables in relationship to inoculation route and prionemia in naturally and experimentally CWD-infected cervids.


Acknowledgments. Support: NIH: RO1-NS-061902 and Morris Animal Foundation: D12ZO-045 P.178: Longitudinal quantitative analysis of CWD prions shed in saliva of deer


Davin M Henderson, Nina Garbino, Nathaniel D Denkers, Amy V Nalls, Candace K Mathiason, and Edward A Hoover Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University; Fort Collins, CO USA


Background/Introduction. Chronic Wasting Disease (CWD) is an emergent rapidly spreading fatal prion disease of cervids (deer, elk and moose). CWD has now been identified in 22 States (including two new states within the last year), 2 Canadian provinces, and South Korea. Shedding of infectious prions in excreta (saliva, urine, feces) may be an important factor in CWD transmission. Here we apply an adapted version of a rapid in vitro assay [real-time quaking-induced conversion (RT-QuIC)] to determine the time of onset, length, pattern, and magnitude of prion shedding in saliva of infected deer.


Materials and Methods. The RT-QuIC assay was performed as previously described in Henderson et al. PLoS-One (2013). Saliva samples were quantitated by comparison to a RT-QuIC reaction rate standard curve of a bioassayed obex sample from a terminally ill cervid.


Results. To better understand the onset and length of CWD prion shedding we analyzed >150 longitudinally collected, blinded, then randomized saliva samples from 17 CWD-infected and 3 uninfected white-tailed deer. We observed prion shedding, as detected by the RT-QuIC assay, as early as 3 months from inoculation and sustained shedding throughout the disease course in both aerosol and orally exposed deer. We estimated the infectious lethal dose of prions shed in saliva from infected deer by comparing real-time reaction rates of saliva samples to a bioassayed serially diluted brain control. Our results indicate that as little as 1 ml of saliva from pre-symptomatic infected deer constitutes a lethal CWD prion dose.


Conclusions. During the pre-symptomatic stage of CWD infection and throughout the course of disease deer may be shedding multiple LD50 doses per day in their saliva. CWD prion shedding through saliva and excreta may account for the unprecedented spread of this prion disease in nature.


Acknowledgments. Supported by NIH grant RO1-NS-061902 and grant D12ZO-045 from the Morris Animal Foundation.



Friday, August 14, 2015


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




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



 P.126: Successful transmission of chronic wasting disease (CWD) into mice over-expressing bovine prion protein (TgSB3985)


Larisa Cervenakova,1 Christina J Sigurdson,2 Pedro Piccardo,3 Oksana Yakovleva,1 Irina Vasilyeva,1 Jorge de Castro,1 Paula Saá,1 and Anton Cervenak1 1American Red Cross, Holland Laboratory; Rockville, MD USA; 2University of California; San Diego, CA USA; 3Lab TSE/OBRR /CBER/FDA; Rockville, MD USA


Keywords: chronic wasting disease, transmission, transgenic mouse, bovine prion protein


Background. CWD is a disease affecting wild and farmraised cervids in North America. Epidemiological studies provide no evidence of CWD transmission to humans. Multiple attempts have failed to infect transgenic mice expressing human PRNP gene with CWD. The extremely low efficiency of PrPCWD to convert normal human PrPC in vitro provides additional evidence that transmission of CWD to humans cannot be easily achieved. However, a concern about the risk of CWD transmission to humans still exists. This study aimed to establish and characterize an experimental model of CWD in TgSB3985 mice with the following attempt of transmission to TgHu mice.


Materials and Methods. TgSB3985 mice and wild-type FVB/ NCrl mice were intracranially injected with 1% brain homogenate from a CWD-infected Tga20 mouse (CWD/Tga20). TgSB3985 and TgRM (over-expressing human PrP) were similarly injected with 5% brain homogenates from CWD-infected white-tailed deer (CWD/WTD) or elk (CWD/Elk). Animals were observed for clinical signs of neurological disease and were euthanized when moribund. Brains and spleens were removed from all mice for PrPCWD detection by Western blotting (WB). A histological analysis of brains from selected animals was performed: brains were scored for the severity of spongiform change, astrogliosis, and PrPCWD deposition in ten brain regions.


Results. Clinical presentation was consistent with TSE. More than 90% of TgSB3985 and wild-type mice infected with CWD/Tga20, tested positive for PrPres in the brain but only mice in the latter group carried PrPCWD in their spleens. We found evidence for co-existence or divergence of two CWD/ Tga20 strains based on biochemical and histological profiles. In TgSB3985 mice infected with CWD-elk or CWD-WTD, no animals tested positive for PrPCWD in the brain or in the spleen by WB. However, on neuropathological examination we found presence of amyloid plaques that stained positive for PrPCWD in three CWD/WTD- and two CWD/Elk-infected TgSB3985 mice. The neuropathologic profiles in CWD/WTD- and CWD/Elkinfected mice were similar but unique as compared to profiles of BSE, BSE-H or CWD/Tg20 agents propagated in TgSB3985 mice. None of CWD-infected TgRM mice tested positive for PrPCWD by WB or by immunohistochemical detection.


Conclusions. To our knowledge, this is the first established experimental model of CWD in TgSB3985. We found evidence for co-existence or divergence of two CWD strains adapted to Tga20 mice and their replication in TgSB3985 mice. Finally, we observed phenotypic differences between cervid-derived CWD and CWD/Tg20 strains upon propagation in TgSB3985 mice. Further studies are underway to characterize these strains. 


P.89: Prions survive long-term burial in soil with some groundwater dissemination


Allister JA Smith,1 Karen Fernie,1 Ben Maddison,2 Keith Bishop,2 Kevin Gough,3 and Robert A Somerville1 1The Roslin Institute; University of Edinburgh; Edinburgh, UK; 2ADAS Biotechnology Group, University of Nottingham; Nottingham, UK; 3University of Nottingham; Nottingham, UK


An intrinsic property of prions is their extreme resistance to degradation. When they are deposited within the environment, whether from inappropriate disposal by man or from fallen diseased livestock, there is the potential to further propagate cases of disease for many years. It is evidenced that the spread of scrapie in sheep and chronic wasting disease in deer have occurred in this manner.


We mimicked such scenarios under large-scale field conditions to determine the extent to which TSE infectivity survives or disseminates in soil and soil water over five years. The mouse passaged BSE strain, 301V, was used to spike buried bovine heads, or was buried as an uncontained bolus in large soil-filled lysimeters. Two soils were examined, a free-draining sandy loam and a water-retentive clay loam.


Infectivity, determined by bioassay in mice, was recovered from all heads exhumed annually for 5 years from both soil types, with little reduction in the amount of infectivity over time. Small amounts of infectivity were found in soil samples immediately surrounding the heads but not in samples remote from them. Commensurate with this there was no evidence of significant lateral movement of infectivity from the bolus buried in a large soil mass. However large amounts of infectivity were recovered at the original bolus burial site in both soils. There was limited vertical upward movement of infectivity from the bolus buried in clay and downward movement from the bolus buried in sand perhaps reflecting the clay soils propensity to flood.


Throughout the course of the experiment rainwater particulate from several lysimeters was trapped on glass-fibre filters. Extracts from these filters were subject to serial PMCA (protein misfolding cyclic amplification) which was optimised using 301V-spiked samples and blinded controls. All positive and negative control samples were correctly determined. We have tested 44 samples from rainwater passed through the clay lysimeter filters, and found 9 positive samples, mainly from the initial 8 months of the experiment.


We conclude that TSE infectivity is likely to survive burial for long time periods with minimal loss of infectivity and limited movement from the original burial site. However PMCA results have shown that there is the potential for rainwater to elute TSErelated material from soil which could lead to the contamination of a wider area. These experiments reinforce the importance of risk assessment when disposing of TSE risk materials.


P.121: Efficient transmission of prion disease through environmental contamination


Sandra Pritzkow, Rodrigo Morales, and Claudio Soto Mitchell Center for Alzheimer’s disease and related Brain disorders; University of Texas Medical School at Houston; Hourston, TX USA


Chronic wasting disease (CWD) is a prion disorder effecting captive and free-ranging deer and elk. The efficient propagation suggests that horizontal transmission through contaminated environment may play an important role. It has been shown that infectious prions enter the environment through saliva, feces, urine, blood or placenta tissue from infected animals, as well as by carcasses from diseased animals and can stay infectious inside soil over several years.


82 Prion Volume 8 Supplement


We hypothesize that environmental components getting in contact with infectious prions can also play a role for the horizontal transmission of prion diseases. To study this issue, surfaces composed of various environmentally relevant materials were exposed to infectious prions and the attachment and retention of infectious material was studied in vitro and in vivo. We analyzed polypropylene, glass, stainless steel, wood, stone, aluminum, concrete and brass surfaces exposed to 263K-infected brain homogenate. For in vitro analyses, the material was incubated in serial dilutions of 263K-brain homogenate, washed thoroughly and analyzed for the presence of PrPSc by PMCA. The results show that even highly diluted PrPSc can bind efficiently to polypropylene, stainless steel, glass, wood and stone and propagate the conversion of normal prion protein. For in vivo experiments, hamsters were ic injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters, inoculated with 263K-contaminated implants of all groups, developed typical signs of prion disease, whereas control animals inoculated with non-contaminated materials did not.


In addition, in order to study the transmission in a more natural setting, we exposed a group of hamster to habit in the presence of spheres composed of various materials that were pretreated with 263K prions. Many of the hamsters exposed to these contaminated materials developed typical signs of the disease that were confirmed by immunohistological and biochemical analyses.


These findings suggest that various surfaces can efficiently bind infectious prions and act as carriers of infectivity, suggesting that diverse elements in the environment may play an important role in horizontal prion transmission.


P.138: Phenotypic diversity in meadow vole (Microtus pennsylvanicus) prion diseases following challenge with chronic wasting disease isolates


Christopher J Johnson,1 Christina M Carlson,1,2 Jay R Schneider,1 Jamie K Wiepz,1 Crystal L Meyerett-Reid,3 Mark D Zabel,3 Joel A Pedersen,2 and Dennis M Heisey1 1USGS National Wildlife Health Center; Madison, WI USA; 2University of Wisconsin— Madison; Madison, WI USA; 3Colorado State University; Fort Collins, CO USA


Chronic wasting disease (CWD), a prion disease of cervids (deer, elk and moose), is spreading unchecked through large sections of North America. Transmission of CWD among cervids is especially facile and can occur through direct animal-toanimal contact and indirectly through contact with prions shed from infected animals. The disease transmission threat posed by CWD to other wildlife species remains unknown, but other species are inevitably exposed to CWD by consumption of infectious materials and through contact with environmental CWD contamination.


In this study, we investigated the transmission and adaptation of various white-tailed deer CWD isolates in the meadow vole (Microtus pennsylvanicus), a native North American rodent that is sympatric with current CWD epizootics that we have previously established is susceptible to CWD. We found that serial subpassage of CWD from white-tailed deer homozygous for glycine at position 96 (96GG) of the prion protein in meadow voles resulted in the selection of a single prion strain that was characterized by homogeneity in incubation period, abnormal prion protein (PrPTSE) glycoform ratio, lesion profile and PrPTSE deposition pattern. In contrast, passage of CWD from heterozygous 96GS genotype deer produced four unique disease phenotypes upon first passage. Subpassage of these types ultimately resulted in selection of a single strain by third passage that was distinct from the 96GG genotype CWD-derived strain.


We also establish that meadow voles are susceptible to CWD via peripheral challenge, albeit with lower attack rates and longer incubation periods. Interestingly, oral challenge of meadow voles with CWD resulted in subclinical infection in primary passage animals, but manifested as clinical prion disease upon subpassage.


Our data establish that meadow voles are permissive to CWD via peripheral exposure route, suggesting they could serve as an environmental reservoir for CWD. Additionally, our data are consistent with the hypothesis that at least two strains of CWD circulate in naturally-infected cervid populations and provide evidence that meadow voles are a useful tool for CWD strain typing.



Prion Disease Detection, PMCA Kinetics, and IgG in Urine from Sheep Naturally/Experimentally Infected with Scrapie and Deer with Preclinical/Clinical Chronic Wasting Disease


▿ Richard Rubenstein1,*, Binggong Chang1, Perry Gray2, Martin Piltch2, Marie S. Bulgin3, Sharon Sorensen-Melson3 and Michael W. Miller4 + Author Affiliations


1Departments of Neurology and Physiology/Pharmacology, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York 11203 2Los Alamos National Laboratory, Los Alamos, New Mexico 87545 3University of Idaho, Caine Veterinary Teaching and Research Center, 1020 E. Homedale Road, Caldwell, Idaho 83607 4Colorado Division of Wildlife, Wildlife Research Center, 317 West Prospect Road, Fort Collins, Colorado 80526-2097 ABSTRACT Prion diseases, also known as transmissible spongiform encephalopathies, are fatal neurodegenerative disorders. Low levels of infectious agent and limited, infrequent success of disease transmissibility and PrPSc detection have been reported with urine from experimentally infected clinical cervids and rodents. We report the detection of prion disease-associated seeding activity (PASA) in urine from naturally and orally infected sheep with clinical scrapie agent and orally infected preclinical and infected white-tailed deer with clinical chronic wasting disease (CWD). This is the first report on PASA detection of PrPSc from the urine of naturally or preclinical prion-diseased ovine or cervids. Detection was achieved by using the surround optical fiber immunoassay (SOFIA) to measure the products of limited serial protein misfolding cyclic amplification (sPMCA). Conversion of PrPC to PrPSc was not influenced by the presence of poly(A) during sPMCA or by the homogeneity of the PrP genotypes between the PrPC source and urine donor animals. Analysis of the sPMCA-SOFIA data resembled a linear, rather than an exponential, course. Compared to uninfected animals, there was a 2- to 4-log increase of proteinase K-sensitive, light chain immunoglobulin G (IgG) fragments in scrapie-infected sheep but not in infected CWD-infected deer. The higher-than-normal range of IgG levels found in the naturally and experimentally infected clinical scrapie-infected sheep were independent of their genotypes. Although analysis of urine samples throughout the course of infection would be necessary to determine the usefulness of altered IgG levels as a disease biomarker, detection of PrPSc from PASA in urine points to its potential value for antemortem diagnosis of prion diseases.


FOOTNOTES Received 13 May 2011. Accepted 14 June 2011. ↵*Corresponding author. Mailing address: Downstate Medical Center, Departments of Neurology and Physiology/Pharmacology, Box 1213, 450 Clarkson Avenue, Brooklyn, NY 11203. Phone: (718) 270-2019. Fax: (718) 270-2459. E-mail: ↵▿ Published ahead of print on 29 June 2011.


Copyright © 2011, American Society for Microbiology. All Rights Reserved.



Thursday, August 13, 2015


Iatrogenic CJD due to pituitary-derived growth hormone with genetically determined incubation times of up to 40 years





Creutzfeldt-Jakob disease 38 years after diagnostic use of human growth hormone



 the warning shots fired over the bow of the boat that were never heard ;




This was used to help cows super ovulate. This tissue was considered to be of greatest risk of containing BSE and consequently transmitting the disease...




Early detection of chronic wasting disease prions in urine of pre-symptomatic deer by real-time quaking-induced conversion assay


Theodore R. John,1 Hermann M. Schätzl1,2,3 and Sabine Gilch1,4,* 1Department of Veterinary Sciences; University of Wyoming; Laramie, WY USA; 2Department of Molecular Biology; University of Wyoming; Laramie, WY USA; 3Faculty of Veterinary Medicine; Department of Comparative Biology and Experimental Medicine; University of Calgary; Calgary, AB Canada; 4Faculty of Veterinary Medicine; Department of Ecosystem and Public Health; University of Calgary; Calgary, AB Canada Keywords: prion, chronic wasting disease, diagnosis, surveillance, RT-QuIC, urine, feces been demonstrated that prions can persist in soil21 and that water in endemic areas can contain CWD-associated PrPSc.22


Prion 7:3, 253–258; May/June 2013; © 2013 Landes Bioscience


Short Communication Short Communication


*Correspondence to: Sabine Gilch; Email: Submitted: 02/07/13; Revised: 03/17/13; Accepted: 03/24/13


Chronic wasting disease (CWD) is a prion disease of captive and free-ranging deer (Odocoileus spp.), elk (Cervus elaphus nelsonii) and moose (Alces alces shirasi). Unlike in most other prion diseases, in CWD prions are shed in urine and feces, which most likely contributes to the horizontal transmission within and between cervid species. To date, CWD ante mortem diagnosis is only possible by immunohistochemical detection of protease resistant prion protein (PrPSc) in tonsil or recto-anal mucosa-associated lymphoid tissue (RA MALT) biopsies, which requires anesthesia of animals. We report on detection of CWD prions in urine collected from pre-symptomatic deer and in fecal extracts by using real time quakinginduced conversion (RT -QuIC). This assay can be useful for non-invasive pre-symptomatic diagnosis and surveillance of CWD.




Chronic wasting disease (CWD) is to date the most contagious prion disease and affects captive and free-ranging elk, deer and moose in North America.1,2 The disease is caused by the accumulation of an abnormally folded isoform of the cellular prion protein PrPC, denominated PrPSc.3,4 CWD is the cervid equivalent of bovine spongiform encephalopathy (BSE), scrapie in sheep and goat5 or Creutzfeldt-Jakob disease (CJD) in humans.6 Although transmission studies of CWD prions to humanized transgenic mice or non-human primates suggest a strong species barrier,7-9 recent in vitro studies have demonstrated that human PrP can be converted by CWD prions into PrPSc upon adaptation.10 Therefore, a potential for zoonotic transmission, as exemplified by BSE,11 cannot be completely excluded.


A huge body of evidence suggests that CWD can be efficiently transmitted horizontally within and between cervid species,12 which may be the reason for geographical spread and increase in case numbers. Horizontal transmission is explained by the rather unusual peripheral distribution of prions in CWD affected animals and the high susceptibility to the disease by oral infection. 13,14 Unlike in most other prion diseases, CWD prions can be found in a wide variety of tissues, such as skeletal and cardiac muscle15,16 or kidney,17 in addition to the lymphoreticular system and blood.18 Furthermore, they are shed in significant amounts in saliva,18,19 urine19 or feces,20 which enables oral infection of animals by foraging on contaminated pastures. In addition, it has been demonstrated that prions can persist in soil21 and that water in endemic areas can contain CWD-associated PrPSc.22


snip...see full text ;



Friday, December 14, 2012


DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012




In the USA, under the Food and Drug Administration’s 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.


Animals considered at high risk for CWD include:


1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and


2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.


Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.


The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES. It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.


Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.


There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.




36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011). The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE). Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison.




The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).




In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion.




In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible. For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.




Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.




*** In areas of North America where CWD has been reported, given that CWD is excreted in faeces, saliva, urine and blood, and survives in the environment for several years where it is able to bind to the soil, there is a medium probability that the environment (including soil) contains CWD. ***




Pooled urine from five terminally CWD infected white-tailed deer was inoculated into nine tg mice. Two of the nine mice developed disease consistent with a TSE at 370 and 376 days post inoculation suggesting infectious prions are present in the urine of infected cervids but at a lower infectivity than other bodily fluids such as saliva.


Haley et al., (2009)



Friday, March 25, 2011


Detection of Prion Protein in Urine-Derived Injectable Fertility Products by a Targeted Proteomic Approach



Friday, March 25, 2011


Detection of Prion Protein in Urine-Derived Injectable Fertility Products by a Targeted Proteomic Approach



Thursday, June 09, 2011


Detection of CWD prions in salivary, urinary, and intestinal tissues of deer: potential mechanisms of prion shedding and transmission



Wednesday, September 08, 2010








Detection of CWD Prions in Salivary and Urinary Tissues of Deer: Potential Mechanisms of Pathogenesis and Prion Shedding


Nicholas J. Haley,1 Candace K. Mathiason,1 Glenn C. Telling2 and Edward A. Hoover1 1Department of Microbiology, Immunology and Pathology; College of Veterinary Medicine and Biomedical Sciences; Colorado State University; Fort Collins, Colorado USA; 2Department of Molecular Biology and Genetics; University of Kentucky; Lexington, Kentucky USA


Key words: chronic wasting disease, transmission, PMCA, pathogenesis, excretion, urine, saliva, salivary gland, urinary bladder, kidney, blood


Saliva and urine are thought to play an important role in the transmission and pathogenesis of chronic wasting disease (CWD) in captive and free-ranging cervids. We have previously identified PrPCWD in a variety of excreta using serial PMCA (sPMCA) and bioassay; however the source of infectious prions in urine and saliva has yet to be identified. In the present study, we applied sPMCA to tissues associated with saliva and urine production and excretion in an effort to seek proximal sources of prion shedding. Oropharyngeal and urogenital tissues, along with blood and obex from CWD-exposed cervids (comprising over 300 individual samples) were analyzed blindly in duplicate and scored based on apparent CWD burden. PrPCWD was detected by three rounds of sPMCA in tissues associated with saliva and urine production and excretion, notably salivary gland and urinary bladder; whereas blood samples from the same animals and concurrent negative controls (n = 116 of 117) remained negative. Route of inoculation and CNS burden appeared to play an important role in terminal prion distribution, in that IV-inoculated animals and those with increasing CNS levels of PrPCWD had higher and more widely distributed accumulation in excretory tissues. PMCA identification of PrPCWD in oropharyngeal and urogenital tissues—in the absence of detection by conventional methods—may indicate the presence of protease- sensitive infectious prions in excretory tissues not revealed by assays employing PK digestion or other means to remove PrPC reactivity. Thus, evaluation of peripheral tissues via sPMCA may allow additional insights into prion transmission, trafficking and pathogenesis.




Identification of Renal Origin for CWD Urinary Prion Excretion in Deer


Davis M. Seelig,1 Nicholas J. Haley,1 Jan P. Langeveld and Edward A. Hoover1 1Colorado State University; Department of Microbiology, Immunology and Pathology; Fort Collins, CO USA; 2Central Institute for Animal Disease Control (CIDC-Lelystad); Lelystad, The Netherlands


Chronic wasting disease (CWD) is an efficiently transmitted prion disease of cervids. Although bioassays have confirmed the presence of infectious prions in urine and other body fluids of infected deer, origin and mechanisms of prion transfer to and shedding in excreta remains unknown. To address these questions, we have developed enhanced immunohistochemistry (IHC) methods employing tyramide signal amplification (TSA) on formalin-fixed, paraffin-embedded (FFPE) tissues of n = 20 CWD-infected white-tailed deer. Using these methods we have demonstrated PrPCWD present granular to clumped aggregates both within the cytoplasm of renal tubule cells and in the interstitium. Cytoplasmic PrPCWD aggregates were detected most commonly in proximal convoluted tubule epithelial cells. PrPCWD was not identified in the lower urinary tract (ureters or bladder) of any CWD-infected animal. In summary, we present evidence for PrPCWD accumulation within the renal tubule cells, which may identify a proximate tissue source and explain the manner by which infectious prions are excreted in the urine of infected deer, thereby leading to the high degree of direct and indirect horizontal transmission of chronic wasting disease.


snip...see more ;



EFSA Journal 2010;8(10):1861




Scientific Opinion on the results of the EU survey for Chronic Wasting Disease (CWD) in cervids1


EFSA Panel on Biological Hazards (BIOHAZ)2, 3 European Food Safety Authority (EFSA), Parma, Italy




The BIOHAZ Panel was asked to provide a scientific opinion drawing conclusions on the occurrence of CWD in the cervid population in the EU, based on the results of a survey set up by the European Commission and aimed at detecting the possible presence of CWD and other TSEs in wild and farmed cervids in the EU during years 2006 to 2010. The survey was designed taking into account recommendations from an earlier 2004 EFSA opinion and established the minimum sample size to be collected from wild and farmed red deer (Cervus elaphus elaphus) from a number of Member States and from wild white-tailed deer (Odocoileus virginianus) from Finland. It also required all Member States to collect additional samples from all cervid species. Overall, approximately 13,000 brain stem samples were collected from cervids of different species in 21 Member States and Norway. No TSE positive results were found. The opinion presents, analyses and discusses the results of the survey, explains the uncertainties involved and outlines the limitations of the survey and its results. It is concluded that the lack of one positive TSE test in the farmed and wild red deer and wild white-tailed deer which were sampled indicates that there is not a cervid TSE epidemic in the EU. It is also concluded that, considering the spreading of CWD within and from clusters in North America, the limitations of the sampling performed in the EU CWD/TSEs survey and the known susceptibility of certain cervid species to CWD, occurrence of cases of TSEs, especially in remote and presently unsampled geographic areas, may not be excluded in cervids in the EU. A few recommendations for further experimental studies and possible future monitoring of CWD/TSEs in EU cervids are also provided.




1. Introduction


1.1. CWD pathogenesis and transmission


Chronic Wasting Disease (CWD) belongs to a group of fatal, neurodegenerative disorders in humans and animals called Transmissible Spongiform Encephalopathies or TSEs. Other TSEs include scrapie in sheep, Bovine Spongiform Encephalopathy (BSE) in cattle and Creutzfeldt-Jakob disease in humans. TSEs are thought to be caused by an abnormal form of proteinaceous agents called prions that are devoid of nucleic acid. According to the prion hypothesis, infection occurs by conversion of normal prion proteins (PrPc) into the disease-associated, misfolded form (PrPres, or PrPCWD when referring to CWD) that is highly resistant to degradation by proteolytic enzymes. Disease is characterized by progressive accumulation of abnormal prions in lymphoid and nervous tissue. During initial stages of infection, PrPCWD is present in tonsil, gut-associated lymphoid tissues and in the enteric nervous system. Thereafter, CWD prions extend to the central nervous system (Williams, 2005). At later stages of infection, PrPCWD is widely distributed in the body and is present in: tonsils, spleen, retina, skeletal muscle, fat, peripheral nervous system, adrenal glands, blood, saliva, lymph nodes, brain and spinal cord and antler velvet. The brainstem at obex, tonsils and retropharyngeal lymph node were determined as the best tissue targets for PrPSc testing (Angers et al., 2009; Race et al., 2009; Spraker et al., 2002; Williams, 2005).


Clinical signs of the disease typically appear after over 1.5 years. The majority of CWD-affected animals are between 3-5 years of age. In experimentally infected deer, minimum incubation was approximately 15 months and mean time from oral infection to death was approximately 23 months (20-25 months). Animals in the later stages of the disease exhibit behavioural changes and progressive loss of body condition. The clinical signs of CWD are not specific and CWD can be confused with other diseases. Most CWD positive tested animals do not show clinical signs. There is no immune response produced in an affected host. Currently there are no treatments or vaccines for prion diseases, and all infections are believed fatal (Williams et al., 2001).


In CWD the horizontal route and the environment seem to play an important role in transmission. Within endemic areas, transmission occurs intra-specifically (among deer of the same species) and inter-specifically (among cervids of different species). Transmission by direct contact occurs too, but the mechanisms are not well known (Miller et al., 2000). Recently, it was shown experimentally in cervid PrP-expressing transgenic mice that CWD can be acquired by aerosols and by nasal exposure, but with long incubation periods (Denkers et al., 2010). Until recently maternal transmission has not been considered important for the maintenance of CWD and PrPCWD has not been detected in the placenta of cervids as in sheep with scrapie (Williams, 2005). However, a recent study demonstrated experimental maternal transmission of CWD in the Asian muntjac deer model (Muntiacus reevesi) and presence of PrPCWD in maternal placenta and mammary tissue of the dam (Mathiason et al., 2010). PrPCWD is shed in the urine and saliva of terminal CWD-infected and pre-symptomatic deer (Haley et al., 2009; Mathiason et al., 2006). CWD prions are also excreted in faeces. This has been shown even during the incubation period; infected mule deer (Odocoileus hemionus) shed CWD prions in faeces 7–11 months before the onset of neurological signs (Tamguney et al., 2009). Environmental contamination by carcass remains and excreta is considered a main source of CWD infectivity (Miller and Williams, 2003; Miller et al., 2004). CWD-prions have been shown to contaminate soil persisting for years. Clay components of soil bind CWD prion proteins with high affinity (Johnson et al., 2006b). PrPCWD has been detected in water too. Very low PrPCWD levels were detected in an environmental water sample from an endemic area and in water processing sample by a very sensitive method, sPMCA (Nichols et al., 2009). CWD can apparently be transmitted by fomites. In an Results of the EU survey for CWD in cervids


EFSA Journal 2010;8(10):1861 6


experimental model, CWD naïve white tailed deer exposed to bedding material and water from pens occupied by CWD-infected animals contracted infection after 15 months (Mathiason et al., 2009). Because CWD is readily transmitted among captive deer and elk concentrated in pens, it is believed that transmission is facilitated by the concentration of animals related to artificial feeding and baiting. Relative susceptibility to transmission among cervids and for other wildlife species has not been established. Some polymorphisms like the G96S polymorphism in white tail deer (Johnson et al., 2006a) and S225F in mule deer (Jewell et al., 2005) seem to provide a reduced susceptibility. The potential for genetic influences on susceptibility relating to the CWD strains identified in North America, as well as to other TSEs, remains under investigation.


The likelihood of interspecies transmission of prion diseases is influenced by the degree of homology of the infective prion proteins (PrPres) with that of the host prion protein (PrPc), giving rise to the concept of a “species barrier” which must be overcome before an infective prion strain from one species causes disease in another species. In addition, different strains of prions may occur within one animal species. At present, research on biological strain typing involves a variety of methods including biological models using laboratory rodents, molecular, and immunohistochemistry (IHC) methods. In vitro conversion experiments indicate that CWD prions can convert human as well as bovine and sheep prion proteins into its abnormal conformer (PrPres), albeit at a very low rate (Raymond et al., 2000). CWD has been experimentally transmitted after intracerebral inoculation to a number of animals, including cattle; however, cattle did not become infected when exposed orally to infective prion proteins specific to CWD (Sigurdson, 2008; Williams, 2005). At present, it can be concluded that the species barrier may not completely protect other cervid species, including reindeer, from CWD (Li et al., 2007).


The former Scientific Steering Committee (SSC) of the European Commission (SSC, 2003) concluded that a theoretical risk for prion transmission to humans consuming products of CWD affected-cervids of all ages in countries where CWD exists cannot be excluded and that transmission risk of prions to domestic animals cannot be excluded either. Later on, an EFSA opinion (EFSA, 2004) concluded that even though human TSE-exposure risk through consumption of game from European cervids could be assumed to be minor, if at all existing, no final conclusion could be drawn due to the overall lack of scientific data. The opinion recognized a potential risk to consumers if a TSE would be present in European cervids; however, it also stressed that at that time no data regarding a risk of TSE infections from cervid products were available.


1.2. CWD occurrence in cervids...




© European Food Safety Authority, 2010




Chronic Wasting Disease, Transmissible Spongiform Encephalopathies, monitoring, cervids, red deer, whitetailed deer.


1 On request from the European Commission, Question No EFSA-Q-2010-00145, adopted on 22 September 2010.


2 Panel members: Olivier Andreoletti, Herbert Budka, Sava Buncic, John D Collins, John Griffin, Tine Hald, Arie Havelaar, James Hope, Günter Klein, James McLauchlin, Christine Müller-Graf, Christophe Nguyen-The, Birgit Noerrung, Luisa Peixe, Miguel Prieto Maradona, Antonia Ricci, John Sofos, John Threlfall, Ivar Vågsholm and Emmanuel Vanopdenbosch. Correspondence:


3 Acknowledgement: The Panel wishes to thank the members of the Working Group on the Results of EU survey for CWD in cervids: Olivier Andreoletti, Dirk Berkvens, Christian Ducrot, Dolores Gavier-Widen, John Griffin, James Hope and Emmanuel Vanopdenbosch for the preparatory work on this scientific opinion and the hearing expert Matthias Greiner for the support provided to this scientific opinion.



Sunday, December 06, 2009


Detection of Sub-Clinical CWD Infection in Conventional Test-Negative Deer Long after Oral Exposure to Urine and Feces from CWD+ Deer


Abstract Background Chronic wasting disease (CWD) of cervids is a prion disease distinguished by high levels of transmissibility, wherein bodily fluids and excretions are thought to play an important role. Using cervid bioassay and established CWD detection methods, we have previously identified infectious prions in saliva and blood but not urine or feces of CWD+ donors. More recently, we identified very low concentrations of CWD prions in urine of deer by cervid PrP transgenic (Tg[CerPrP]) mouse bioassay and serial protein misfolding cyclic amplification (sPMCA). This finding led us to examine further our initial cervid bioassay experiments using sPMCA.


Objectives We sought to investigate whether conventional test-negative deer, previously exposed orally to urine and feces from CWD+ sources, may be harboring low level CWD infection not evident in the 19 month observation period. We further attempted to determine the peripheral PrPCWD distribution in these animals.


Methods Various neural and lymphoid tissues from conventional test-negative deer were reanalyzed for CWD prions by sPMCA and cervid transgenic mouse bioassay in parallel with appropriate tissue-matched positive and negative controls.


Results PrPCWD was detected in the tissues of orally exposed deer by both sPMCA and Tg[CerPrP] mouse bioassay; each assay revealed very low levels of CWD prions previously undetectable by western blot, ELISA, or IHC. Serial PMCA analysis of individual tissues identified that obex alone was positive in 4 of 5 urine/feces exposed deer. PrPCWD was amplified from both lymphoid and neural tissues of positive control deer but not from identical tissues of negative control deer.


Discussion Detection of subclinical infection in deer orally exposed to urine and feces (1) suggests that a prolonged subclinical state can exist, necessitating observation periods in excess of two years to detect CWD infection, and (2) illustrates the sensitive and specific application of sPMCA in the diagnosis of low-level prion infection. Based on these results, it is possible that low doses of prions, e.g. following oral exposure to urine and saliva of CWD-infected deer, bypass significant amplification in the LRS, perhaps utilizing a neural conduit between the alimentary tract and CNS, as has been demonstrated in some other prion diseases.




In summary, we provide evidence for the presence of infectious prions in the brains of conventional prion-assay-negative deer orally exposed 19 months earlier to urine and feces from CWD-infected donor deer. This apparent low level of prion infection was amplified by sPMCA, confirmed by Tg[CerPrP] mouse bioassay, and detected only in the obex region of the brain. These results demonstrate the potential for CWD prion transmission via urine and/or feces, and highlight the application of more sensitive assays such as sPMCA in identification of CWD infection, pathogenesis, and prevalence.




Wednesday, March 18, 2009


Detection of CWD Prions in Urine and Saliva of Deer by Transgenic Mouse Bioassay



Detection of infectious prions in urine


Dennisse Gonzalez-Romero, Marcelo A. Barria, Patricia Leon, Rodrigo Morales, Claudio Soto* George and Cynthia Mitchell Center for Neurodegenerative diseases, Departments of Neurology, Neuroscience and Cell Biology and Biochemistry and Molecular Biology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0646, USA Received 26 July 2008; accepted 4 August 2008


Available online 13 August 2008


Edited by Aleksander Benjak




Prions are the infectious agents responsible for prion diseases, which appear to be composed exclusively by the misfolded prion protein (PrPSc). The mechanism of prion transmission is unknown. In this study, we attempted to detect prions in urine of experimentally infected animals. PrPSc was detected in 80% of the animals studied, whereas no false positives were observed among the control animals. Semi-quantitative calculations suggest that PrPSc concentration in urine is around 10-fold lower than in blood. Interestingly, PrPSc present in urine maintains its infectious properties. Our data indicate that low quantities of infectious prions are excreted in the urine. These findings suggest that urine is a possible source of prion transmission.


2008 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved. Keywords: Prion; Transmissible


see full text ;







Tuesday, September 02, 2008


Detection of infectious prions in urine (Soto et al Available online 13 August 2008.)



 doi:10.1016/j.febslet.2008.08.003 Copyright © 2008 Published by Elsevier B.V.


Detection of infectious prions in urine


Dennisse Gonzalez-Romeroa, Marcelo A. Barriaa, Patricia Leona, Rodrigo Moralesa and Claudio Soto, a,



Sunday, August 02, 2015 HAVE YOU BEEN THUNDERSTRUCK ?





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





Tuesday, August 11, 2015


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



Wednesday, March 04, 2015


*** Disease sampling results provide current snapshot of CWD in Wisconsin finding 324 positive detections statewide in 2014



Friday, June 01, 2012





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, August 20, 2015





Thursday, August 20, 2015


TEXAS CAPTIVE Deer Industry, Pens, Breeding, Big Business, Invites Crooks and CWD



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




*** Danger of Canned Hunting Indiana Wildlife ***



a review since the TEXAS 84th Legislature commencing this January, deer breeders are expected to advocate for bills that will seek to further deregulate their industry...


Sunday, December 14, 2014


TEXAS 84th Legislature commencing this January, deer breeders are expected to advocate for bills that will seek to further deregulate their industry



Tuesday, December 16, 2014


Texas 84th Legislature 2015 H.R. No. 2597 Kuempel Deer Breeding Industry TAHC TPWD CWD TSE PRION



Under Texas law, though, breeder deer belong to the state, not the permittee. See, e.g., TEX. PARKS & WILD. CODE §§ 1.011 (“All wild animals . . . inside the borders of this state are the property of the people of this state.”); 43.364 (“All breeder deer . . . are under the full force of the laws of [Texas] pertaining to deer . . . .”). While a permittee may have possession of the breeder deer, the deer are only “held under a permit[.]” Id. § 43.351. Nowhere do the statutes or regulations state that breeder deer become the property of a permit holder.4 Regardless, even if they did give ownership of breeder deer to permit holders, the Andertons were not permit holders when the deer were killed.



While a permittee may have possession of the breeder deer, the deer are only “held under a permit[.]” Id. § 43.351



Monday, August 24, 2015


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



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







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)



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.



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.



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


Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3



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.









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.




***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


Conversely, FSE maintained sufficient BSE characteristics to more efficiently convert bovine rPrP than feline rPrP. 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.




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







Sunday, August 25, 2013


HD.13: CWD infection in the spleen of humanized transgenic mice


Liuting Qing and Qingzhong Kong


Case Western Reserve University; Cleveland, OH USA


Chronic wasting disease (CWD) is a widespread prion disease in free-ranging and captive cervid species in North America, and there is evidence suggesting the existence of multiple CWD strains. The susceptibility of human CNS and peripheral organs to the various CWD prion strains remains largely unclear. Current literature suggests that the classical CWD strain is unlikely to infect human brain, but the potential for peripheral infection by CWD in humans is unknown. We detected protease-resistant PrpSc in the spleens of a few humanized transgenic mice that were intracerebrally inoculated with natural CWD isolates, but PrpSc was not detected in the brains of any of the CWD-inoculated mice. Our ongoing bioassays in humanized Tg mice indicate that intracerebral challenge with such PrpSc-positive humanized mouse spleen already led to prion disease in most animals. ***These results indicate that the CWD prion may have the potential to infect human peripheral lymphoid tissues.


Oral.15: Molecular barriers to zoonotic prion transmission: Comparison of the ability of sheep, cattle and deer prion disease isolates to convert normal human prion protein to its pathological isoform in a cell-free system


Marcelo A.Barria,1 Aru Balachandran,2 Masanori Morita,3 Tetsuyuki Kitamoto,4 Rona Barron,5 Jean Manson,5 Richard Kniqht,1 James W. lronside1 and Mark W. Head1


1National CJD Research and Surveillance Unit; Centre for Clinical Brain Sciences; School of Clinical Sciences; The University of Edinburgh; Edinburgh, UK; 2National and OIE Reference Laboratory for Scrapie and CWD; Canadian Food Inspection Agency; Ottawa Laboratory; Fallowfield. ON Canada; 3Infectious Pathogen Research Section; Central Research Laboratory; Japan Blood Products Organization; Kobe, Japan; 4Department of Neurological Science; Tohoku University Graduate School of Medicine; Sendai. Japan; 5Neurobiology Division; The Roslin Institute and R(D)SVS; University of Edinburgh; Easter Bush; Midlothian; Edinburgh, UK


Background. Bovine spongiform encephalopathy (BSE) is a known zoonotic prion disease, resulting in variant Creurzfeldt- Jakob disease (vCJD) in humans. In contrast, classical scrapie in sheep is thought to offer little or no danger to human health. However, a widening range of prion diseases have been recognized in cattle, sheep and deer. The risks posed by individual animal prion diseases to human health cannot be determined a priori and are difficult to assess empirically. The fundamemal event in prion disease pathogenesis is thought to be the seeded conversion of normal prion protein (PrPC) to its pathological isoform (PrPSc). Here we report the use of a rapid molecular conversion assay to test whether brain specimens from different animal prion diseases are capable of seeding the conversion of human PrPC ro PrPSc.


Material and Methods. Classical BSE (C-type BSE), H-type BSE, L-type BSE, classical scrapie, atypical scrapie, chronic wasting disease and vCJD brain homogenates were tested for their ability to seed conversion of human PrPC to PrPSc in protein misfolding cyclic amplification (PMCA) reactions. Newly formed human PrPSc was detected by protease digestion and western blotting using the antibody 3F4.


Results. C-type BSE and vCJD were found to efficiently convert PrPC to PrPSc. Scrapie failed to convert human PrPC to PrPSc. Of the other animal prion diseases tested only chronic wasting disease appeared to have the capability ro convert human PrPC to PrPSc. The results were consistent whether the human PrPC came from human brain, humanised transgenic mouse brain or from cultured human cells and the effect was more pronounced for PrPC with methionine at codon 129 compared with that with valine.


Conclusion. Our results show that none of the tested animal prion disease isolates are as efficient as C-type BSE and vCJD in converting human prion protein in this in vitro assay. ***However, they also show that there is no absolute barrier ro conversion of human prion protein in the case of chronic wasting disease.




Sunday, August 25, 2013


***Chronic Wasting Disease CWD risk factors, humans, domestic cats, blood, and mother to offspring transmission



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. ***



*** IF CWD is not a risk factor for humans, then I guess the FDA et al recalled all this CWD tainted elk tenderloin (2009 Exotic Meats USA of San Antonio, TX) for the welfare and safety of the dead elk. ...tss


Exotic Meats USA Announces Urgent Statewide Recall of Elk Tenderloin Because It May Contain Meat Derived From An Elk Confirmed To Have Chronic Wasting Disease


Contact: Exotic Meats USA 1-800-680-4375


FOR IMMEDIATE RELEASE -- February 9, 2009 -- Exotic Meats USA of San Antonio, TX is initiating a voluntary recall of Elk Tenderloin because it may contain meat derived from an elk confirmed to have Chronic Wasting Disease (CWD). The meat with production dates of December 29, 30 and 31, 2008 was purchased from Sierra Meat Company in Reno, NV. The infected elk came from Elk Farm LLC in Pine Island, MN and was among animals slaughtered and processed at USDA facility Noah’s Ark Processors LLC.


Chronic Wasting Disease (CWD) is a fatal brain and nervous system disease found in elk and deer. The disease is caused by an abnormally shaped protein called a prion, which can damage the brain and nerves of animals in the deer family. Currently, it is believed that the prion responsible for causing CWD in deer and elk is not capable of infecting humans who eat deer or elk contaminated with the prion, but the observation of animal-to-human transmission of other prion-mediated diseases, such as bovine spongiform encephalopathy (BSE), has raised a theoretical concern regarding the transmission of CWD from deer or elk to humans. At the present time, FDA believes the risk of becoming ill from eating CWD-positive elk or deer meat is remote. However, FDA strongly advises consumers to return the product to the place of purchase, rather than disposing of it themselves, due to environmental concerns.


Exotic Meats USA purchased 1 case of Elk Tenderloins weighing 16.9 lbs. The Elk Tenderloin was sold from January 16 – 27, 2009. The Elk Tenderloins was packaged in individual vacuum packs weighing approximately 3 pounds each. A total of six packs of the Elk Tenderloins were sold to the public at the Exotic Meats USA retail store. Consumers who still have the Elk Tenderloins should return the product to Exotic Meats USA at 1003 NE Loop 410, San Antonio, TX 78209. Customers with concerns or questions about the Voluntary Elk Recall can call 1-800-680-4375. The safety of our customer has always been and always will be our number one priority.


Exotic Meats USA requests that for those customers who have products with the production dates in question, do not consume or sell them and return them to the point of purchase. Customers should return the product to the vendor. The vendor should return it to the distributor and the distributor should work with the state to decide upon how best to dispose. If the consumer is disposing of the product he/she should consult with the local state EPA office.




RSS Feed for FDA Recalls Information11 [what's this?12]



Thursday, May 26, 2011


Travel History, Hunting, and Venison Consumption Related to Prion Disease Exposure, 2006-2007 FoodNet Population Survey Journal of the American Dietetic Association Volume 111, Issue 6 , Pages 858-863, June 2011.



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 ;





*** 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.






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. <<<




Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle


Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.




The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...



In Confidence - Perceptions of unconventional slow virus diseases of animals in the USA - APRIL-MAY 1989 - G A H Wells


3. Prof. A. Robertson gave a brief account of BSE. The US approach was to accord it a very low profile indeed. Dr. A Thiermann showed the picture in the ''Independent'' with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs. ...



*** 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.



Tuesday, August 4, 2015


*** FDA U.S. Measures to Protect Against BSE ***



Thursday, September 10, 2015


25th Meeting of the Transmissible Spongiform Encephalopathies Advisory Committee Food and Drug Administration Silver Spring, Maryland June 1, 2015



Monday, August 17, 2015


FDA Says Endoscope Makers Failed to Report Superbug Problems OLYMPUS


I told Olympus 15 years ago about these risk factors from endoscopy equipment, disinfection, even spoke with the Doctor at Olympus, this was back in 1999. I tried to tell them that they were exposing patients to dangerous pathogens such as the CJD TSE prion, because they could not properly clean them. even presented my concern to a peer review journal GUT, that was going to publish, but then it was pulled by Professor Michael Farthing et al... see ;



Sunday, December 14, 2014


ALERT new variant Creutzfeldt Jakob Disease nvCJD or vCJD, sporadic CJD strains, TSE prion aka Mad Cow Disease United States of America Update December 14, 2014 Report



Sunday, August 11, 2013


Creutzfeldt-Jakob Disease CJD cases rising North America updated report August 2013


Creutzfeldt-Jakob Disease CJD cases rising North America with Canada seeing an extreme increase of 48% between 2008 and 2010



*** 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).***




Terry S. Singeltary Sr.


Post a Comment

Subscribe to Post Comments [Atom]

<< Home