Southwest Wisconsin CWD, Deer and Predator Study
Southwest Wisconsin CWD, Deer and Predator Study
This study comprehensively examines factors that could influence deer population change in southwestern Wisconsin. These include Chronic Wasting Disease, predation, habitat suitability and hunter harvest.
TIMELINE
Launch: July 2017 Completion: June 2021
FUNDING
Pittman-Robertson
DNR PARTNER BUREAU Wildlife Management EXTERNAL STAKEHOLDERS Deer hunters Private landowners Conservation Congress CDAC Interested Public
January, 2016 marked the beginning of the largest and most comprehensive deer research project ever undertaken in Wisconsin: The Southwest Wisconsin CWD, Deer and Predator Study. This initiative stems from Governor Scott Walker’s commitment to reevaluating chronic wasting disease in Wisconsin.
This study is principally concerned with the potential for CWD to negatively impact deer populations. We are exploring the infection rates at which CWD reduces deer survival and reproduction enough to reduce deer populations. However, many other factors can influence deer populations, including hunting, predation and habitat quality. Therefore researchers will closely track these factors as well. This study will also estimate the abundance and distribution of bobcats and coyotes within the study areas and will examine their impact on deer survival and behavior.
KEY POINTS
» The Southwest Wisconsin Deer and Predator Research Project was announced in May 2016 as part of the Governor’s CWD Initiative. The overall research goal is to comprehensively examine factors that could influence deer population change.
» OAS will work with volunteers and landowners to collar deer, coyotes and bobcats and then release them back into the wild for monitoring.
» DNR staff intend to collar animals for a total of four years. We will continue to monitor these animals for several years after collaring concludes.
» Obtaining a genetic sample from each collared deer will determine whether genes governing CWD susceptibility influence deer survival.
» Collaring deer, bobcats and coyotes allows researchers to determine survival rates, causes of mortality, movements and habitat use of these animals.
» We welcome more volunteer landowners to join the study. Landowner participation is crucial for our success, and we appreciate their support in making this study possible.
CWD prions remain infectious after passage through the digestive system of coyotes (Canis latrans)
Tracy A Nichols1,*, Justin W Fischer1 , Terry R Spraker2,3, Qingzhong Kong4 , and Kurt C VerCauteren1 1 National Wildlife Research Center; United States Department of Agriculture; Animal and Plant Health Inspection Service; Wildlife Services; Fort Collins, CO USA; 2 Colorado State University Diagnostic Laboratory; College of Veterinary Medicine; Colorado State University; Fort Collins, CO USA; 3 Department of Microbiology, Immunology and Pathology; College of Veterinary Medicine and Biomedical Sciences; Colorado State University Prion Research Center; Fort Collins, CO USA; 4 National Prion Disease Pathology Surveillance Center; Institute of Pathology; Case Western Reserve University; Cleveland, OH USA
ABSTRACT.
Chronic wasting disease (CWD) is a geographically expanding prion disease of wild and captive cervids in North America. Disease can be transmitted directly, animal to animal, or indirectly via the environment. CWD contamination can occur residually in the environment via soil, water, and forage following deposition of bodily fluids such as urine, saliva, and feces, or by the decomposition of carcasses. Recent work has indicated that plants may even take up prions into the stems and leaves. When a carcass or gut pile is present in the environment, a large number of avian and mammalian species visit and consume the carrion. Additionally, predators like coyotes, likely select for disease-compromised cervids. Natural cross-species CWD transmission has not been documented, however, passage of infectious prion material has been observed in the feces of crows. In this study we evaluated the ability of CWD-infected brain material to pass through the gastrointestinal tract of coyotes (Canis latrans) following oral ingestion, and be infectious in a cervidized transgenic mouse model. Results from this study indicate that coyotes can pass infectious prions via their feces for at least 3 days post ingestion, demonstrating that mammalian scavengers could contribute to the translocation and contamination of CWD in the environment.
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DISCUSSION
The continued spread of CWD is of concern to the health of both wild and captive cervid populations. Indirect transmission through the environment has been demonstrated in captive animals living in paddocks where CWD-positive animals had lived,3 and is a particular challenge due to the long persistence of CWD within the environment.7,28 Infectious material can be deposited in the environment by the decay of infected carcasses, from urine, feces, and saliva,5,6,29 and the spread of infected material may be aided by scavengers and predators. In this study we illustrated the ability of coyotes to pass infectivity in their feces after the ingestion of CWD-infected brain homogenate. Coyotes have the ability to travel significant distances. This distance, however, is based upon social structure, which is generally placed in 2 categories; resident or transient.30 Resident animals are those that utilize a specific territory and are comprised of a mated pair and sometimes pups from a previous year, while transient animals are individuals that are nomadic, more commonly male, and have no affinity for a specific territory.30 In a study evaluating the range of coyotes in southern Colorado, transient animals, which represented 22% of the population, ranged over 106.5 § 27 km2 , versus resident groups which ranged over 11.3 § 5.8 km.2,30 Transient coyotes are therefore provided an opportunity to translocate disease to previously CWD-negative localities.
Control coyotes readily consumed the homogenized elk brain. Of the treatment coyotes, which were moved indoors 2 days prior to the initiation of the study, only one (#135) immediately ate the brain homogenate. The other coyotes required supplementation with diced, raw chicken, or fishflavored soft cat food. Although the numbers are too small to come to any definitive conclusions, it is interesting to note that the coyote that ingested the brain homogenate without chicken or cat food supplementation did not appear to transfer infectivity to any of the mice in the bioassay. Neither age nor sex appeared to have any effect on fecal shedding. However, it is possible that individual variation within the stomach environment, such as pH and flora could have influenced the passage of the infectious prions through the gastrointestinal tract. Our experimental design was based on detection of CWD in coyote feces by PMCA prior to initiation of the bioassay. PMCA was able to repeatedly detect the presence of proteinase K-resistant prions signal in feces from DPI 1, so the bioassay was designed to evaluate feces for 2 days following, to account for any uncertainty in prion detection in feces. Results from the bioassay showed transmission of disease to 2/4 mouse groups in DPI 3, suggesting that infectivity may continue to be present in the feces more than 3 days after ingestion. We were unable to go back and increase the bioassay to include DPI 4 and 5, due to logistical reasons.
The 50 mL oral dose ingested by coyotes in this study was comprised solely of infected brain tissue and represented a high dose. In the wild, coyotes would opportunistically consume a wide variety of tissues from a kill or scavenged deer or elk carcass, likely making their actual ingested infective dose much smaller. This study was not designed to mimic a naturally consumed dose of CWD, but rather as a proof of concept to determine if infectivity could pass into coyote feces. The passage of disease in feces is a common route of translocation for many viral, bacterial and parasitic diseases.
The results of this bioassay indicate that infectious CWD prions are able to be passed in the feces of coyotes fed infected elk brain homogenate for at least 3 DPI, making them a potential vector for CWD prion transport and contamination within the environment.
KEYWORDS. chronic wasting disease, coyotes, environmental contamination, feces, prions, scavengers, transmission
Tracy A Nichols, Justin W Fischer, Terry R Spraker, Qingzhong Kong, and Kurt C VerCauteren *Correspondence to: Tracy A Nichols; Email: tracy.a.nichols@aphis.usda.gov Received July 7, 2015; Revised August 5, 2015; Accepted August 18, 2015. Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/ kprn.
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
The moral rights of the named author(s) have been asserted.
SUNDAY, NOVEMBER 01, 2009 American crows (Corvus brachyrhynchos) and potential spreading of CWD through feces of digested infectious carcases Could Crows Play a Role in Spreading CWD
was presented by Dr. Kurt VerCauteren, NWRC, WS-APHIS- USDA. From the first observations (40 years ago) of CWD in mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus nelsoni) in Northern Colorado, the disease has been identified in an increasing geographic area. Mechanisms for the spread of CWD are incompletely understood. Birds have been identified as potential vectors for a number of diseases, where infected material is ingested and the disease agent is later shed in new areas after flying substantial distances. We hypothesized that avian scavengers have the potential to disseminate 200 prions associated with transmissible spongiform encephalopathies (TSEs), like CWD, by a similar process. As prions are resistant to destruction, it is reasonable that infectious material could pass through the digestive tract of scavenging birds. Our objective was to determine if TSE-positive brain material from mice (i.e., mouse-adapted scrapie) could pass through the digestive tract of American crows (Corvus
American crows (Corvus brachyrhynchos) and potential spreading of CWD through feces of digested infectious carcasses
brachyrhynchos) and still be infectious to mice. Our experimental design included treatment groups of mice inoculated intraperitoneally with: 1) normal mouse brain, 2) infected mouse brain, 3) gamma-irradiated feces from crows gavaged with normal mouse brain, and 4) gamma-irradiated feces from crows gavaged with infected mouse brain. Our preliminary results indicate feces from each of 20 crows gavaged with infected mouse brain were infectious for mice (proportion of crows=1.00, 95% CI: 0.83-1.00) and average longevity for mice was 213 days (95% CI: 210-216). Longevity of mice inoculated with infected mouse brain was slightly less (198 days, 95% CI: 188-207). Most mice inoculated with normal brain, or feces from crows gavaged with normal brain, were still alive 1 year post inoculation with no evident clinical signs of TSE disease in any control mice. Our results demonstrate that a common, migratory North American scavenger, the American crow, can pass infective prions in feces and, therefore, could play a role in the spatial dissemination of prion disease....
Chronic wasting disease (CWD), first identified in Wisconsin in 2002, is an infectious transmissible spongiform encephalopathy (TSE) afflicting members of the taxonomic family Cervidae, and causes neurodegeneration and ultimately death. As a proxy for mortality or harvest of CWD-infected deer, we placed disease-free white-tailed deer (Odocoileus virginianus) carcasses and gut piles in the environment and monitored scavenger activity and carcass removal from September to April in 2003 through 2005. We recorded 14 species of scavenging mammals (six species of visitors), and eight species of scavenging birds (14 species of visitors). Prominent scavengers included American crows (Corvus brachyrhynchos), raccoons (Procyon lotor), and Virginia opossums (Didelphis virginiana). We found no evidence that deer directly consumed conspecific remains, but they visited carcasses and gut piles. Domestic dogs (Canis familiaris), cats (Felis sylvestris catus), and cows (Bos spp.) either scavenged or visited carcass sites, which may have increased exposure risk of CWD to humans and human food supplies. Deer carcasses persisted for a median of 18 to 101 days, while gut piles lasted for a median of three days. Habitat did not influence carcass consumption/decomposition, but mammalian and avian scavenger activity and higher temperatures (proxy for microbial and arthropod activity) were associated with greater rates of carcass removal.
Our findings suggest that infected deer carcasses can function as an environmental source of CWD prions to mammalian and avian scavengers. We discuss the implications of these results in a broader context of CWD spread, and suggest preemptive management strategies for mitigating impacts of CWD contaminated deer remains in the environment....
EP-021 Canine Prions: A New Form of Prion Disease
Mourad Tayebi1, Monique A David2, Brian Summers3 1 University of Melbourne, Veterinary Sciences, Australia; 2Ausbiologics, Sydney, Australia; 3Royal Veterinary College, London, UK
The origin of bovine spongiform encephalopathy (BSE), which rapidly evolved into a major epidemic remains unresolved and was initially widely attributed to transmission of sheep scrapie to cattle with contaminated feed prepared from rendered sheep carcasses. Alternative transmission hypotheses also include feed contaminated with unrecognized subclinical case(s) of bovine prion disease or with prion-infected human remains. However, following the demonstration of a BSE case exhibiting the novel mutation E211 K, similar to the E200K mutation associated with most genetic CJD in humans, support for a genetic origin of prion disease in cattle is gaining momentum. In contrast to other animal species such as feline, the canine species seems to be resistant to prion disease as no canine prion cases were previously reported. We describe here three cases of Rottweiler puppy (called RWD cases) with neurological deficits and spongiform change. We used animal bioassays and in vitro studies to show efficient interspecies transmission of this novel canidae prion isolate to other species. Biochemical studies revealed the presence of partially proteinase K (PK)-resistant fragment and immunohistochemistry displayed staining for PrPSc in the cerebral cortex. Importantly, interspecies transmission of canine PrPSc derived from RWD3 brain homogenates following inoculation of hamsters led to signs of prion disease and replication of PrPSc in brains, spinal cords and spleens of these animals. These findings if confirmed by further cases of prion disease in canidae and regardless of the origin of the disease would have a major impact on animal and public health.
PRION 2016 TOKYO
http://prion2016.org/
OR-09: Canine spongiform encephalopathy—A new form of animal prion disease
Monique David, Mourad Tayebi UT Health; Houston, TX USA
It was also hypothesized that BSE might have originated from an unrecognized sporadic or genetic case of bovine prion disease incorporated into cattle feed or even cattle feed contaminated with prion-infected human remains.1 However, strong support for a genetic origin of BSE has recently been demonstrated in an H-type BSE case exhibiting the novel mutation E211K.2 Furthermore, a specific prion protein strain causing BSE in cattle is believed to be the etiological agent responsible for the novel human prion disease, variant Creutzfeldt-Jakob disease (vCJD).3 Cases of vCJD have been identified in a number countries, including France, Italy, Ireland, the Netherlands, Canada, Japan, US and the UK with the largest number of cases. Naturally occurring feline spongiform encephalopathy of domestic cats4 and spongiform encephalopathies of a number of zoo animals so-called exotic ungulate encephalopathies5,6 are also recognized as animal prion diseases, and are thought to have resulted from the same BSE-contaminated food given to cattle and humans, although and at least in some of these cases, a sporadic and/or genetic etiology cannot be ruled out. The canine species seems to display resistance to prion disease and no single case has so far been reported.7,8
Here, we describe a case of a 9 week old male Rottweiler puppy presenting neurological deficits; and histological examination revealed spongiform vacuolation characteristic of those associated with prion diseases.9 Initial biochemical studies using anti-PrP antibodies revealed the presence of partially proteinase K-resistant fragment by western blotting. Furthermore, immunohistochemistry revealed spongiform degeneration consistent with those found in prion disease and displayed staining for PrPSc in the cortex.
Of major importance, PrPSc isolated from the Rottweiler was able to cross the species barrier transmitted to hamster in vitro with PMCA and in vivo (one hamster out of 5). Futhermore, second in vivo passage to hamsters, led to 100% attack rate (n = 4) and animals displayed untypical lesional profile and shorter incubation period.
In this study, we show that the canine species might be sensitive to prion disease and that PrPSc isolated from a dog can be transmitted to dogs and hamsters in vitro using PMCA and in vivo to hamsters.
If our preliminary results are confirmed, the proposal will have a major impact on animal and public health and would certainly lead to implementing new control measures for ‘canine spongiform encephalopathy’ (CSE).
References
1. Colchester AC, Colchester NT. The origin of bovine spongiform encephalopathy: the human prion disease hypothesis. Lancet 2005; 366:856-61; PMID:16139661; http:// dx.doi.org/10.1016/S0140-6736(05)67218-2.
2. Richt JA, Hall SM. BSE case associated with prion protein gene mutation. PLoS Pathog 2008; 4:e1000156; PMID:18787697; http://dx.doi.org/10.1371/journal. ppat.1000156.
3. Collinge J. Human prion diseases and bovine spongiform encephalopathy (BSE). Hum Mol Genet 1997; 6:1699-705; PMID:9300662; http://dx.doi.org/10.1093/ hmg/6.10.1699.
4. Wyatt JM, Pearson GR, Smerdon TN, Gruffydd-Jones TJ, Wells GA, Wilesmith JW. Naturally occurring scrapie-like spongiform encephalopathy in five domestic cats. Vet Rec 1991; 129:233-6; PMID:1957458; http://dx.doi.org/10.1136/vr.129.11.233.
5. Jeffrey M, Wells GA. Spongiform encephalopathy in a nyala (Tragelaphus angasi). Vet Pathol 1988; 25:398-9; PMID:3232315; http://dx.doi.org/10.1177/030098588802500514.
6. Kirkwood JK, Wells GA, Wilesmith JW, Cunningham AA, Jackson SI. Spongiform encephalopathy in an arabian oryx (Oryx leucoryx) and a greater kudu (Tragelaphus strepsiceros). Vet Rec 1990; 127:418-20; PMID:2264242.
7. Bartz JC, McKenzie DI, Bessen RA, Marsh RF, Aiken JM. Transmissible mink encephalopathy species barrier effect between ferret and mink: PrP gene and protein analysis. J Gen Virol 1994; 75:2947-53; PMID:7964604; http://dx.doi.org/10.1099/0022-1317- 75-11-2947.
8. Lysek DA, Schorn C, Nivon LG, Esteve-Moya V, Christen B, Calzolai L, et al. Prion protein NMR structures of cats, dogs, pigs, and sheep. Proc Natl Acad Sci U S A 2005; 102:640-5; PMID:15647367; http://dx.doi.org/10.1073/pnas.0408937102.
9. Budka H. Neuropathology of prion diseases. Br Med Bull 2003; 66:121-30; PMID:14522854; http://dx.doi.org/10.1093/bmb/66.1.121.
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2013
Strain characteristics of the in vitro-adapted rabbit and dog BSE agent remained invariable with respect to the original cattle BSE prion, suggesting that the naturally low susceptibility of rabbits and dogs to prion infections should not alter their zoonotic potential if these animals became infected with BSE.
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Neurobiology of Disease
Bovine Spongiform Encephalopathy Induces Misfolding of Alleged Prion-Resistant Species Cellular Prion Protein without Altering Its Pathobiological Features
Enric Vidal3, Natalia Fernández-Borges1, Belén Pintado4, Montserrat Ordóñez3, Mercedes Márquez6, Dolors Fondevila5,6, Juan María Torres7, Martí Pumarola5,6, and Joaquín Castilla1,2 + Author Affiliations
1CIC bioGUNE, 48160 Derio, Bizkaia, Spain,
2IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Bizkaia, Spain,
3Centre de Recerca en Sanitat Animal, Campus de la Universitat Autònoma de Barcelona (UAB)-IRTA, 08193 Bellaterra, Barcelona, Spain,
4Centro Nacional de Biotecnología, Campus de Cantoblanco, 28049 Cantoblanco, Madrid, Spain,
5Department of Animal Medicine and Surgery, Veterinary Faculty, UAB, 08193 Bellaterra (Cerdanyola del Vallès), Barcelona, Spain,
6Murine Pathology Unit, Centre de Biotecnologia Animal i Teràpia Gènica, UAB, 08193 Bellaterra (Cerdanyola del Vallès), Barcelona, Spain, and
7Centro de Investigación en Sanidad Animal-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28130 Valdeolmos, Madrid, Spain
Author contributions: E.V., N.F.-B., and J.C. designed research; E.V., N.F.-B., B.P., M.O., M.M., D.F., and J.C. performed research; E.V., N.F.-B., B.P., and J.C. contributed unpublished reagents/analytic tools; E.V., N.F.-B., B.P., M.O., M.M., D.F., J.M.T., M.P., and J.C. analyzed data; E.V. and J.C. wrote the paper.
Abstract
Bovine spongiform encephalopathy (BSE) prions were responsible for an unforeseen epizootic in cattle which had a vast social, economic, and public health impact. This was primarily because BSE prions were found to be transmissible to humans. Other species were also susceptible to BSE either by natural infection (e.g., felids, caprids) or in experimental settings (e.g., sheep, mice). However, certain species closely related to humans, such as canids and leporids, were apparently resistant to BSE. In vitro prion amplification techniques (saPMCA) were used to successfully misfold the cellular prion protein (PrPc) of these allegedly resistant species into a BSE-type prion protein. The biochemical and biological properties of the new prions generated in vitro after seeding rabbit and dog brain homogenates with classical BSE were studied. Pathobiological features of the resultant prion strains were determined after their inoculation into transgenic mice expressing bovine and human PrPC. Strain characteristics of the in vitro-adapted rabbit and dog BSE agent remained invariable with respect to the original cattle BSE prion, suggesting that the naturally low susceptibility of rabbits and dogs to prion infections should not alter their zoonotic potential if these animals became infected with BSE. This study provides a sound basis for risk assessment regarding prion diseases in purportedly resistant species.
Received January 18, 2013. Revision received March 7, 2013. Accepted March 23, 2013. Copyright © 2013 the authors 0270-6474/13/337778-09$15.00/0
Friday, March 8, 2013
Dogs may have been used to make Petfood and animal feed
Monday, March 26, 2012
CANINE SPONGIFORM ENCEPHALOPATHY: A NEW FORM OF ANIMAL PRION DISEASE
http://caninespongiformencephalopathy.blogspot.com/2012/03/canine-spongiform-encephalopathy-new.html
Monday, February 14, 2011
THE ROLE OF PREDATION IN DISEASE CONTROL: A COMPARISON OF SELECTIVE AND NONSELECTIVE REMOVAL ON PRION DISEASE DYNAMICS IN DEER
NO, NO, NOT NO, BUT HELL NO !
Journal of Wildlife Diseases, 47(1), 2011, pp. 78-93 © Wildlife Disease Association 2011
Monday, March 8, 2010
Canine Spongiform Encephalopathy aka MAD DOG DISEASE
*** DEFRA TO SINGELTARY ON HOUND STUDY AND BSE 2001 ***
DEFRA Department for Environment, Food & Rural Affairs
Area 307, London, SW1P 4PQ Telephone: 0207 904 6000 Direct line: 0207 904 6287 E-mail: h.mcdonagh.defra.gsi.gov.uk
GTN: FAX:
Mr T S Singeltary P.O. Box 42 Bacliff Texas USA 77518
21 November 2001
Dear Mr Singeltary
TSE IN HOUNDS
Thank you for e-mail regarding the hounds survey. I am sorry for the long delay in responding.
As you note, the hound survey remains unpublished. However the Spongiform Encephalopathy Advisory Committee (SEAC), the UK Government's independent Advisory Committee on all aspects related to BSE-like disease, gave the hound study detailed consideration at their meeting in January 1994. As a summary of this meeting published in the BSE inquiry noted, the Committee were clearly concerned about the work that had been carried out, concluding that there had clearly been problems with it, particularly the control on the histology, and that it was more or less inconclusive. However was agreed that there should be a re-evaluation of the pathological material in the study.
Later, at their meeting in June 95, The Committee re-evaluated the hound study to see if any useful results could be gained from it. The Chairman concluded that there were varying opinions within the Committee on further work. It did not suggest any further transmission studies and thought that the lack of clinical data was a major weakness.
Overall, it is clear that SEAC had major concerns about the survey as conducted. As a result it is likely that the authors felt that it would not stand up to r~eer review and hence it was never published. As noted above, and in the detailed minutes of the SEAC meeting in June 95, SEAC considered whether additional work should be performed to examine dogs for evidence of TSE infection. Although the Committee had mixed views about the merits of conducting further work, the Chairman noted that when the Southwood Committee made their recommendation to complete an assessment of possible spongiform disease in dogs, no TSEs had been identified in other species and hence dogs were perceived as a high risk population and worthy of study. However subsequent to the original recommendation, made in 1990, a number of other species had been identified with TSE ( e.g. cats) so a study in hounds was less
critical. For more details see- http://www.bseinquiry.gov.uk/files/yb/1995/06/21005001.pdf
new url;
As this study remains unpublished, my understanding is that the ownership of the data essentially remains with the original researchers. Thus unfortunately, I am unable to help with your request to supply information on the hound survey directly. My only suggestion is that you contact one of the researchers originally involved in the project, such as Gerald Wells. He can be contacted at the following address.
Dr Gerald Wells, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey, KT 15 3NB, UK
You may also wish to be aware that since November 1994 all suspected cases of spongiform encephalopathy in animals and poultry were made notifiable. Hence since that date there has been a requirement for vets to report any suspect SE in dogs for further investigation. To date there has never been positive identification of a TSE in a dog.
I hope this is helpful
Yours sincerely 4
HUGH MCDONAGH BSE CORRESPONDENCE SECTION
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HOUND SURVEY
I am sorry, but I really could have been a co-signatory of Gerald's minute.
I do NOT think that we can justify devoting any resources to this study, especially as larger and more important projects such as the pathogenesis study will be quite demanding.
If there is a POLITICAL need to continue with the examination of hound brains then it should be passed entirely to the VI Service.
J W WILESMITH Epidemiology Unit 18 October 1991
Mr. R Bradley
cc: Mr. G A H Wells
see new url;
3.3. Mr R J Higgins in conjunction with Mr G A Wells and Mr A C Scott would by the end of the year, indentify the three brains that were from the ''POSITIVE'' end of the lesion spectrum.
see new url;
TSE in dogs have not been documented simply because OF THE ONLY STUDY, those brain tissue samples were screwed up too. see my investigation of this here, and to follow, later follow up, a letter from defra, AND SEE SUSPICIOUS BRAIN TISSUE SAF's. ...TSS
TSE & HOUNDS
GAH WELLS (very important statement here...TSS)
HOUND STUDY
AS implied in the Inset 25 we must not _ASSUME_ that transmission of BSE to other species will invariably present pathology typical of a scrapie-like disease.
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76 pages on hound study;
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The spongiform changes were not pathognomonic (ie. conclusive proof) for prion disease, as they were atypical, being largely present in white matter rather than grey matter in the brain and spinal cord. However, Tony Scott, then head of electron microscopy work on TSEs, had no doubt that these SAFs were genuine and that these hounds therefore must have had a scrapie-like disease. I reviewed all the sections myself (original notes appended) and although the pathology was not typical, I could not exclude the possibility that this was a scrapie-like disorder, as white matter vacuolation is seen in TSEs and Wallerian degeneration was also present in the white matter of the hounds, another feature of scrapie.
38.I reviewed the literature on hound neuropathology, and discovered that micrographs and descriptive neuropathology from papers on 'hound ataxia' mirrored those in material from Robert Higgins' hound survey. Dr Tony Palmer (Cambridge) had done much of this work, and I obtained original sections from hound ataxia cases from him. This enabled me provisionally to conclude that Robert Higgins had in all probability detected hound ataxia, but also that hound ataxia itself was possibly a TSE. Gerald Wells confirmed in 'blind' examination of single restricted microscopic fields that there was no distinction between the white matter vacuolation present in BSE and scrapie cases, and that occurring in hound ataxia and the hound survey cases.
39.Hound ataxia had reportedly been occurring since the 1930's, and a known risk factor for its development was the feeding to hounds of downer cows, and particularly bovine offal. Circumstantial evidence suggests that bovine offal may also be causal in FSE, and TME in mink. Despite the inconclusive nature of the neuropathology, it was clearly evident that this putative canine spongiform encephalopathy merited further investigation.
40.The inconclusive results in hounds were never confirmed, nor was the link with hound ataxia pursued. I telephoned Robert Higgins six years after he first sent the slides to CVL. I was informed that despite his submitting a yearly report to the CVO including the suggestion that the hound work be continued, no further work had been done since 1991. This was surprising, to say the very least.
41.The hound work could have provided valuable evidence that a scrapie-like agent may have been present in cattle offal long before the BSE epidemic was recognised. The MAFF hound survey remains unpublished.
Histopathological support to various other published MAFF experiments
42.These included neuropathological examination of material from experiments studying the attempted transmission of BSE to chickens and pigs (CVL 1991) and to mice (RVC 1994).
It was thought likely that at least some, and probably all, of the cases in zoo animals were caused by the BSE agent. Strong support for this hypothesis came from the findings of Bruce and others (1994) ( Bruce, M.E., Chree, A., McConnell, I., Foster, J., Pearson, G. & Fraser, H. (1994) Transmission of bovine spongiform encephalopathy and scrapie to mice: strain variation and species barrier. Philosophical Transactions of the Royal Society B 343, 405-411: J/PTRSL/343/405 ), who demonstrated that the pattern of variation in incubation period and lesion profile in six strains of mice inoculated with brain homogenates from an affected kudu and the nyala, was similar to that seen when this panel of mouse strains was inoculated with brain from cattle with BSE. The affected zoo bovids were all from herds that were exposed to feeds that were likely to have contained contaminated ruminant-derived protein and the zoo felids had been exposed, if only occasionally in some cases, to tissues from cattle unfit for human consumption.
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10. The case of SE in a cheetah that occurred during the period, involved a 7 year-old female which had been born and lived all her life at Whipsnade (except for the final stages when she was moved to the Animal Hospital at Regent’s Park for diagnosis and treatment). This animal, which died in December 1993, had been fed on cuts of meat and bone from carcases of cattle unfit for human consumption and it was thought likely that she had been exposed to spinal cord (Kirkwood, J.K., Cunningham, A.A., Flach, E.J., Thornton, S.M. & Wells, G.A.H. (1995) Spongiform encephalopathy in another captive cheetah (Acinonyx jubatus): evidence for variation in susceptibility or incubation periods between species. Journal of Zoo and Wildlife Medicine 26, 577-582: J/ZWM/26/577).
11. During the period we also collated information on cases of SE that occurred in wild animals at or from other zoos in the British Isles. The total number of cases of which I was aware in June 1996, when I presented a review on occurrence of spongiform encephalopathies in zoo animals (at the Royal College of Pathologists’ Symposium on Transmitting prions: BSE, CJD, and other TSEs, The Royal Society, London, 4th July 1996), was 25, involving 10 species. The animals involved were all from the families Bovidae and Felidae, and comprised: 1 Nyala Tragelaphus angasi, 5 Eland Taurotragus oryx, 6 greater kudu Tragelaphus strepsiceros, 1 Gemsbok Oryx gazella, 1 Arabian oryx Oryx leucoryx, 1 Scimitar-horned oryx Oryx dammah, 4 Cheetah Acinonyx jubatus, 3 Puma Felis concolor 2 Ocelot Felis pardalis, and 1 Tiger Panthera tigris. (A spongiform encephalopathy, which was thought probably to have a different aetiology, had also been reported in 3 ostriches Struthio camelus in Germany). This list did not include cases of BSE in domesticated species in zoos (ie BSE in Ankole or other cattle, or SEs, assumed to be scrapie, in mouflon sheep Ovis musimon).
NEW URL ;
MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019
BSE INQUIRY EVIDENCE
Why did the appearance of new TSEs in animals matter so much? It has always been known that TSEs will transfer across species boundaries. The reason for this was never known until the genetic nature of the prion gene was fully investigated and found to be involved. The gene is found to have well preserved sites and as such there is a similar gene throughout the animal kingdom...and indeed a similar gene is found in insects! It is NOT clear that the precise close nature of the PrP gene structure is essention for low species barriers. Indeed it is probably easier to infect cats with BSE than it is to infect sheep. As such it is not clear that simply because it is possible to infect BSE from cattle into certain monkeys then other apes will necessarily be infectable with the disease. One factor has stood out, however, and that is that BSE, when inoculated into mice would retain its apparent nature of disease strain, and hence when it was inoculated back into cattle, then the same disease was produced. Similarly if the TSE from kudu was inoculated into mice then a similar distribution of disease in the brain of the mouse is seen as if BSE had been inoculated into the mouse. This phenomenon was not true with scrapie, in which the transmission across a species barrier was known to lose many of the scrapie strain phenomena in terms of incubation period or disease histopathology. This also suggested that BSE was not derived from scrapie originally but we probably will never know.
------------------------------------------------------------------------
TSE in wild UK deer? The first case of BSE (as we now realise) was in a nyala in London zoo and the further zoo cases in ungulates were simply thought of as being interesting transmissions of scrapie initially. The big problem started to appear with animals in 1993-5 when it became clear that there was an increase in the CJD cases in people that had eaten deer although the statistics involved must have been questionable. The reason for this was that the CJD Surveillance was well funded to look into the diet of people dying of CJD. This effect is not clear with vCJD...if only because the numbers involved are much smaller and hence it is difficult to gain enough statistics. They found that many other foods did not appear to have much association at all but that deer certainly did and as years went by the association actually became clearer. The appearance of vCJD in 1996 made all this much more difficult in that it was suddenly clearer that the cases of sporadic CJD that they had been checking up until then probably had nothing to do with beef...and the study decreased. During the period there was an increasing worry that deer were involved with CJD..
see references:
DEER BRAIN SURVEY
i have not updated my blogspot url with all this data archived, but i will work on it...but until then, i have updated this on the above links with live urls to the actual BSE Inquiry documents...
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler
Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ References: <3daf5023 .4080804="" a="" fg_scanned="1" href="http://wt.net/" rel="noopener noreferrer" style="color: blue; cursor: pointer;" target="_blank">WT.NET
Dear Terry,
An excellent piece of review as this literature is desparately difficult to get back from Government sites.
What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported. Well, if you dont look adequately like they are in USA currenly then you wont find any!
Steve Dealler ===============
BSE Inquiry Steve Dealler
Management In Confidence
BSE: Private Submission of Bovine Brain Dealler
reports of sheep and calf carcasses dumped...
re-scrapie to cattle GAH Wells BSE Inquiry
https://web.archive.org/web/20090506043931/http://www.bseinquiry.gov.uk/files/yb/1993/12/09001001.pdf
https://web.archive.org/web/20090506065716/http://www.bseinquiry.gov.uk/files/yb/1995/06/21005001.pdf
Dr. Dealler goes rogue to confirm BSE
Confirmation BSE Dealler's mad cow
BSE vertical transmission
1993 cjd report finds relationship with eat venison and cjd increases 9 fold, let the cover up begin...tss
FINDINGS
*** 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). ***
*** 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). ***
*** 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). ***
There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02)..
The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).
snip...
It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).
snip...
In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...
snip...
In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)
snip...see full report ;
GAME FARM INDUSTRY WANTS TO COVER UP FINDINGS OF INCREASE RISK TO CJD FROM CERVID
BSE INQUIRY
CJD9/10022
October 1994
Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane
BerksWell Coventry CV7 7BZ
Dear Mr Elmhirst,
CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT
Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.
The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended.. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.
The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.
The statistical results reqarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.
I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.
The BSE Inquiry / Statement No 324
Dr James Kirkwood (not scheduled to give oral evidence)
Statement to the BSE Inquiry
James K Kirkwood BVSc PhD FIBiol MRCVS
[This witness has not been asked to give oral evidence in Phase 1 of the Inquiry]
1. I became involved in the field of TSEs through my work as Head of the Veterinary Science Group at the Zoological Society of London’s Institute of Zoology. I held this post from November 1984 until June 1996, when I took up my present post at UFAW. During this time, concurrent with the BSE epidemic, cases of scrapie-like spongiform encephalopathies occurred in animals at the Zoological Society of London’s collections at Regent’s Park and Whipsnade and in other zoos. It was appropriate to investigate the epidemiology of these cases in order to try to determine the possible impact on zoo animals and breeding programmes, and to consider how the disease in zoo animals might be controlled.
2. Throughout the period from 1985 to March 1996, I worked at the Institute of Zoology (IoZ). I was Head of the Veterinary Science Group of the IoZ and Senior Veterinary Officer of the Zoological Society of London (ZSL). I was responsible for the provision of the veterinary service for the ZSL collections.
3. During the period from 1985 to March 1996, scrapie-like spongiform encephalopathies were diagnosed in the following animals which died, or were euthanased, at London Zoo and Whipsnade:
Animal Sex Date of Death Age (mos)
Arabian Oryx Oryx leucoryx F 24.3.89 38
Greater kudu Tragelaphus strepsiceros (Linda) F 18.8.89 30
Greater kudu (Karla) F 13.11.90 19 Greater kudu (Kaz) M 6.6.91 37
Greater kudu (Bambi) M 24.10.91 36
Greater kudu (346/90) M 26.2.92 18
Greater kudu (324/90) F 22.11.92 38
Cheetah Acinonyx jubatus (Michelle) F 22.12.93 91
All these cases were described in papers published in the scientific literature (as cited below).
EYES, RETINA, SHOULD NOT BE USED IN SCHOOLS, BAB, SOB, MRM,
BSE, PET FOOD, CRUSHED HEADS
IN PARTICULAR CRUSHED HEADS
YOU explained that imported crushed heads were extensively used in the petfood industry...
In particular I do not believe one can say that the levels of the scrapie agent in pet food are so low that domestic animals are not exposed.
BSE IN PETFOOD
1. The Secretary asked on 19 April whether I was content with the advice in para 3 of the record of the meeting on 17 March with the Parliamentary Secretary (Mr Thompson). The simple answer is ''not entirely''.
2. On occasions, material obtained from slaughterhouses will be derived from sheep affected with scrapie or cattle that may be incubating BSE for use in petfood manufacture. Some of this material must be classified as high risk since it contains brain, spinal cord, spleen or lymphatic glands.
Meldrum's notes on pet foods and materials used
IN CONFIDENCE CJD TO CATS...
It should be noted that under experimental conditions cats succumb to an encephalopathy after intracerebral inoculation of material derived from patients affected with Creutzfeldt-Jakob Disease.
Confidential BSE and __________________
3. I have thought very hard about whether the Branch should carry out a similar exercise with meat and meat products for human foods. On balance I do NOT think we should undertake it, but a final decision has not been taken and you may wish to discuss this further. ...
1st case natural FSE
NATURAL SPONGIFORM ENCEPHALOPATHY IN A DOMESTIC CAT
1. We have heard from MAFF that a domestic Siamese cat from the Bristol area has had spongiform encephalopathy confirmed. Although there are previous instances of experimental infection in cats, there have been no previous natural infections reported. The assumption must be the cat became infected by scrapie/BSE agent in it's food. ...
FSE and pharmaceuticals
1. An analysis by MCA Professional staff of the results to the questionnaire sent out to industry to obtain additional data about the use of animal materials of any origin in the manufacture of pharmaceutical products for human use, reveals that material of feline or canine origin is used in only two licensed products. In both instances the material is sourced from outside the U.K. and from areas currently believed to be free from B.S.E.
CONFIDENTIAL
Confidential cats/dogs and unsatisfactory posture MAFFs failure to assure key research
3. First, I am very uneasy about the relative lack of urgency and interest that MAFF appear to hold for getting the necessary research programme on BSE and related encephalopathies started, and getting it going fast. FOR EXAMPLE, MR BRADLEY of CVL said that there were difficulties in organizing transmission experiments from the brain of the cat which died of an encephalopathy in Bristol. There were arguments going on about who should pay for this work. Should it be MAFF, the Bristol Veterinary School or someone else? Dr. Tyrrell was clearly exasperated.
snip...
11. The Committee were even LESS FORTHCOMING on what their reaction might be if an encephalopathy is found in another species, perhaps in DOGS. Their first reaction was that, as with the cats, the first step could be to investigate whether this was really a new disease, or simply one that had not previously been recognized and to see whether it has any links to BSE, scrapie or other transmissible encephalopathies. Indeed, some members of the Committee seem to regard the whole question of another species as a hypothetical question to be addressed only when it happened. A rather UNSATISFACTORY POSTURE.
12. In advance of your meeting with Dr Tyrrell on Monday morning, I have not voiced my ANXIETIES about the support the Committee is receiving from MAFF to anyone OTHER THAN DR PICKLES. ...
SPONGIFORM ENCEPHALOPATHY IN A CAPTIVE PUMA
an article in yesterday's Times (attached) which suggested that the puma concerned had never ''eaten any part of a cow or sheep which, in the opinion of Government Scientists, could transmit the species to a different species''.
3. You explained to me that this was INCORRECT. The position was as set out in the briefing for Prime Minister's questions attached to Mr Taylor's note. The puma had probably been fed low quality beef meat in the form of split carcasses. ...
Subject: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY Date: Thu, 17 Oct 2002 17:04:51 -0700 From: "Terry S. Singeltary Sr." Reply-To: Bovine Spongiform Encephalopathy To: BSE-L
Greetings BSE-L,
is there any other CWD surveys/testing in the UK on their deer? what sort of testing has been done to date on UK/EU deer? any input would be helpful... thank you
DEER SPONGIFORM ENCEPHALOPATHY SURVEY
3. This will be a low key study with no publicity to avoid unnecessary media interest. It will be carried out in two stages ;
(I) A small scale examination of around 30 deer brains to establish the normal histology of the healthy brain; and
(II) A larger scale random examination of 300 or more adult deer brains drawn from both deer farms and parks to establish whether there is any evidence of a cervine spongiform encephalopathy. ...
Ministry of Agriculture Fisheries and Food Veterinary Investigation Centre West House. Station Road. Thirsk Y07 IPZ Telephone: 0845·522065 Fax: 0845·525224
Your reference
Our reference RJH/ASB
Date 4 November 1992
DEER SPONGIFORM ENCEPHALOPATHY SURVEY
Dear Paul
I have now found time to review the 10 deer- brains collected from Mr Walker farm··via Winchester Via Winchester VIC. In answer to your specific question was there sufficient difference in preservation of brain tissue to warrant the extra effort involved in rapid brain removal on the farm, the answer is definitely "Yes." The original five brains (Winchester ref M487/11) showed varying degrees of autolytic vacuolation affecting both white and grey matter throughout the brain. vacuolation and separation of Purkinje cells and marked perivascular spaces. These artifacts made interpretation of subtle, specific pathological vacuolation more difficult. By contrast the second submission (Winchester reference N736/2) showed excellent preservation of white and grey matter. Any vacuolar Change present could be confidently interpreted as pathological albeit of unknown pathogenesis.
I can only reiterate the comments made by Gerald Wells and myself at the preliminary discussion at Weybridge in Autumn 1991. If the survey's purpose is an accurate histopathological interpretation of brain tissue. the material must be collected in a pristine state. This is particularly valid when looking for ar unrecognised and undefined spongiform encephalopathy in a new species. Deer brains are very large structures which take a lot of fixation and therefore must be handled sympathetically from the start. We have already seen the problems encountered in comparatively smaller hound brains where delayed fixation was a major limitation on interpretation of true pathological change.
The bottom line must be that if a pathologist's expertise is to be used, it is critical to collect artefact free brain material. If the politics or economics do not allow this, then I would suggest that an electron microscopy survey involving detection of scrapie associated fibrils would be much more appropriate.
Best wishes Yours sincerely
R J HIGGINS VIO 92/11.4/2.1
HOUND SURVEY
I am sorry, but I really could have been a co-signatory of Gerald's minute.
I do NOT think that we can justify devoting any resources to this study, especially as larger and more important projects such as the pathogenesis study will be quite demanding.
If there is a POLITICAL need to continue with the examination of hound brains then it should be passed entirely to the VI Service.
J W WILESMITH Epidemiology Unit 18 October 1991
Mr. R Bradley
cc: Mr. G A H Wells
***> 3.3. Mr R J Higgins in conjunction with Mr G A Wells and Mr A C Scott would by the end of the year, identify the three brains that were from the ''POSITIVE'' end of the lesion spectrum.
HOUND SURVEY PATHOLOGICAL REPORT (see positive results) and MAD DOGS AND ENGLISHMAN...
ya'll thought i was making this stuff up didn't ya...i don't make this stuff up!
It is clear that the designing scientists must also have shared Mr Bradley's surprise at the results because all the dose levels right down to 1 gram triggered infection.
second supplementary
Why did the appearance of new TSEs in animals matter so much? It has always been known that TSEs will transfer across species boundaries. The reason for this was never known until the genetic nature of the prion gene was fully investigated and found to be involved. The gene is found to have well preserved sites and as such there is a similar gene throughout the animal kingdom...and indeed a similar gene is found in insects! It is NOT clear that the precise close nature of the PrP gene structure is essention for low species barriers. Indeed it is probably easier to infect cats with BSE than it is to infect sheep. As such it is not clear that simply because it is possible to infect BSE from cattle into certain monkeys then other apes will necessarily be infectable with the disease. One factor has stood out, however, and that is that BSE, when inoculated into mice would retain its apparent nature of disease strain, and hence when it was inoculated back into cattle, then the same disease was produced. Similarly if the TSE from kudu was inoculated into mice then a similar distribution of disease in the brain of the mouse is seen as if BSE had been inoculated into the mouse. This phenomenon was not true with scrapie, in which the transmission across a species barrier was known to lose many of the scrapie strain phenomena in terms of incubation period or disease histopathology. This also suggested that BSE was not derived from scrapie originally but we probably will never know.
------------------------------------------------------------------------
TSE in wild UK deer? The first case of BSE (as we now realise) was in a nyala in London zoo and the further zoo cases in ungulates were simply thought of as being interesting transmissions of scrapie initially. The big problem started to appear with animals in 1993-5 when it became clear that there was an increase in the CJD cases in people that had eaten deer although the statistics involved must have been questionable. The reason for this was that the CJD Surveillance was well funded to look into the diet of people dying of CJD. This effect is not clear with vCJD...if only because the numbers involved are much smaller and hence it is difficult to gain enough statistics. They found that many other foods did not appear to have much association at all but that deer certainly did and as years went by the association actually became clearer. The appearance of vCJD in 1996 made all this much more difficult in that it was suddenly clearer that the cases of sporadic CJD that they had been checking up until then probably had nothing to do with beef...and the study decreased. During the period there was an increasing worry that deer were involved with CJD..
see references:
DEER BRAIN SURVEY
1993 cjd report finds relationship with eat venison and cjd increases 9 fold, let the cover up begin...tss
FINDINGS
*** 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). ***
There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02)..
The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).
snip...
It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).
snip...
In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...
snip...
In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)
snip...see full report ;
GAME FARM INDUSTRY WANTS TO COVER UP FINDINGS OF INCREASE RISK TO CJD FROM CERVID
BSE INQUIRY
CJD9/10022
October 1994
Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane
BerksWell Coventry CV7 7BZ
Dear Mr Elmhirst,
CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT
Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.
The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended.. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.
The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.
The statistical results reqarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.
I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.
http://web.archive.org/web/20030511010117/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
Management In Confidence
BSE: Private Submission of Bovine Brain Dealler
Subject: Re: DEER SPONGIFORM ENCEPHALOPATHY SURVEY & HOUND STUDY
Date: Fri, 18 Oct 2002 23:12:22 +0100
From: Steve Dealler
Reply-To: Bovine Spongiform Encephalopathy Organization: Netscape Online member
To: BSE-L@ References: <3daf5023 .4080804="" a="" fg_scanned="1" href="http://wt.net/" nbsp="" rel="noopener noreferrer" style="color: blue; cursor: pointer;" target="_blank">wt.net
Dear Terry,
An excellent piece of review as this literature is desparately difficult to get back from Government sites.
What happened with the deer was that an association between deer meat eating and sporadic CJD was found in about 1993. The evidence was not great but did not disappear after several years of asking CJD cases what they had eaten. I think that the work into deer disease largely stopped because it was not helpful to the UK industry...and no specific cases were reported. Well, if you dont look adequately like they are in USA currenly then you wont find any!
Steve Dealler
Stephen Dealler is a consultant medical microbiologist deal@airtime.co.uk
===============
===============
U.S.A. 50 STATE BSE MAD COW CONFERENCE CALL Jan. 9, 2001
Subject: BSE--U.S. 50 STATE CONFERENCE CALL Jan. 9, 2001
Date: Tue, 9 Jan 2001 16:49:00 -0800
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy
snip...
[host Richard Barns] and now a question from Terry S. Singeltary of CJD Watch.
[TSS] yes, thank you, U.S. cattle, what kind of guarantee can you give for serum or tissue donor herds?
[no answer, you could hear in the back ground, mumbling and 'we can't. have him ask the question again.]
[host Richard] could you repeat the question?
[TSS] U.S. cattle, what kind of guarantee can you give for serum or tissue donor herds?
[not sure whom ask this] what group are you with?
[TSS] CJD Watch, my Mom died from hvCJD and we are tracking CJD world-wide.
[not sure who is speaking] could you please disconnect Mr. Singeltary
[TSS] you are not going to answer my question?
[not sure whom speaking] NO
snip...see full archive and more of this;
===============
OFFICIAL REPORT U.K. GOVERNMENT DEFRA
What is the risk of chronic wasting disease being introduced into Great Britain? A Qualitative Risk Assessment October 2012
Several different animal feed products are imported into GB from North America. These include processed pet foods and consignments of unfinished feed ingredients for use in animal feed. The amount of imported feed, including pet food, that contains cervid protein is unknown and identified as a significant data gap. As non-ruminant animal feed may be produced with cervid protein (but not from positive CWD animals) in the United States (US), there is a greater than negligible risk that feed with cervid protein is imported from North America into GB. There is, however, uncertainty associated with this estimate.
snip...
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.
snip...
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.
snip...
What is the risk of chronic wasting disease being introduced into Great Britain? A Qualitative Risk Assessment October 2012
Thursday, April 07, 2016
What is the risk of chronic wasting disease being introduced into Great Britain? An updated Qualitative Risk Assessment March 2016
1999
15 November 1999
Terry S Singeltary
NA
Re: vCJD in the USA * BSE in U.S.
In reading the recent article in the BMJ about the potential BSE tests being developed in the U.S. and Bart Van Everbroeck reply. It does not surprize me, that the U.S. has been concealing vCJD. There have been people dying from CJD, with all the symptoms and pathological findings that resemble U.K. vCJD for some time. It just seems that when there is one found, they seem to change the clarical classification of the disease, to fit their agenda. I have several autopsies, stating kuru type amyloid plaques, one of the victims was 41 years of age. Also, my Mom died a most hideous death, Heidenhain Variant Creutzfeldt Jakob disease. Her symptoms resemble that of all the U.K. vCJD victims. She would jerk so bad at times, it would take 3 of us to hold her down, while she screamed "God, what's wrong with me, why can't I stop this." 1st of symptoms to death, 10 weeks, she went blind in the first few weeks. But, then they told me that this was just another strain of sporadic CJD. They can call it what ever they want, but I know what I saw, and what she went through. Sporadic, simply means, they do not know.
My neighbors Mom also died from CJD. She had been taking a nutritional supplement which contained the following;
vacuum dried bovine BRAIN, bone meal, bovine EYE, veal bone, bovine liver powder, bovine adrenal, vacuum dried bovine kidney, and vacuum dried porcine stomach. As I said, this woman taking these nutritional supplements, died from CJD.
The particular batch of pills that was located, in which she was taking, was tested. From what I have heard, they came up negative, for the prion protein. But, in the same breath, they said their testing, may not have been strong enough to pick up the infectivity. Plus, she had been taking these type pills for years, so, could it have come from another batch?
CWD is just a small piece of a very big puzzle. I have seen while deer hunting, deer, squirrels and birds, eating from cattle feed troughs where they feed cattle, the high protein cattle by products, at least up until Aug. 4, 1997.
So why would it be so hard to believe that this is how they might become infected with a TSE.
Or, even by potentially infected land. It's been well documented that it could be possible, from scrapie.
Cats becoming infected with a TSE. Have you ever read the ingredients on the labels of cat and dog food? But, they do not put these tissues from these animals in pharmaceuticals, cosmetics, nutritional supplements, hGH, hPG, blood products, heart valves, and the many more products that come from bovine, ovine, or porcine tissues and organs.
So, as I said, this CWD would be a small piece of a very big puzzle. But, it is here, and it most likely has killed. You see, greed is what caused this catastrophe, rendering and feeding practices. But, once Pandora's box was opened, the potential routes of infection became endless.
No BSE in the U.S.A.? I would not be so sure of that considering that since 1990;
Since 1990 the U.S. has raised 1,250,880,700 cattle;
Since 1990 the U.S. has ONLY checked 8,881 cattle brains for BSE, as of Oct. 4, 1999;
There are apprx. 100,000 DOWNER cattle annually in the U.S., that up until Aug. 4, 1997 went to the renders for feed;
Scrapie running rampant for years in the U.S., 950 infected FLOCKS, as of Aug. 1999;
Our feeding and rendering practices have mirrored that of the U.K. for years, some say it was worse. Everything from the downer cattle, to those scrapie infected sheep, to any roadkill, including the city police horse and the circus elephant went to the renders for feed and other products for consumption. Then they only implemented a partial feed ban on Aug. 4, 1997, but pigs, chickens, dogs, and cats, and humans were exempt from that ban. So they can still feed pigs and chickens those potentially TSE tainted by-products, and then they can still feed those by-products back to the cows. I believe it was Dr. Joe Gibbs, that said, the prion protein, can survive the digestinal track. So you have stopped nothing.
It was proven in Oprah Winfrey's trial, that Cactus Cattle feeders, sent neurologically ill cattle, some with encephalopathy stamped on the dead slips, were picked up and sent to the renders, along with sheep carcasses. Speaking of autopsies, I have a stack of them, from CJD victims. You would be surprised of the number of them, who ate cow brains, elk brains, deer brains, or hog brains.
I believe all these TSE's are going to be related, and originally caused by the same greedy Industries, and they will be many. Not just the Renders, but you now see, that they are re-using medical devices that were meant for disposal. Some medical institutions do not follow proper auto- claving procedures (even Olympus has put out a medical warning on their endescopes about CJD, and the fact you cannot properly clean these instruments from TSE's), and this is just one product. Another route of infection.
Regardless what the Federal Government in the U.S. says. It's here, I have seen it, and the longer they keep sweeping it under the rug and denying the fact that we have a serious problem, one that could surpass aids (not now, but in the years to come, due to the incubation period), they will be responsible for the continued spreading of this deadly disease.
It's their move, it's CHECK, but once CHECKMATE has been called, how many thousands or millions, will be at risk or infected or even dead. You can't play around with these TSE's. I cannot stress that enough. They are only looking at body bags, and the fact the count is so low. But, then you have to look at the fact it is not a reportable disease in most states, mis-diagnosis, no autopsies performed. The fact that their one-in-a- million theory is a crude survey done about 5 years ago, that's a joke, under the above circumstances. A bad joke indeed........
The truth will come, but how many more have to die such a hideous death. It's the Government's call, and they need to make a serious move, soon. This problem, potential epidemic, is not going away, by itself.
Terry S. Singeltary Sr.
P.O. Box ,
Bacliff, Texas 77518 USA
flounder@wt.net
Competing interests: No competing interests
2000
02 January 2000
Terry S Singeltary
U.S. Scientist should be concerned with a CJD epidemic in the U.S., as well...
In reading your short article about 'Scientist warn of CJD epidemic' news in brief Jan. 1, 2000. I find the findings in the PNAS old news, made famous again. Why is the U.S. still sitting on their butts, ignoring the facts? We have the beginning of a CJD epidemic in the U.S., and the U.S. Gov. is doing everything in it's power to conceal it.
The exact same recipe for B.S.E. existed in the U.S. for years and years. In reading over the Qualitative Analysis of BSE Risk Factors-1, this is a 25 page report by the USDA:APHIS:VS. It could have been done in one page. The first page, fourth paragraph says it all;
"Similarities exist in the two countries usage of continuous rendering technology and the lack of usage of solvents, however, large differences still remain with other risk factors which greatly reduce the potential risk at the national level."
Then, the next 24 pages tries to down-play the high risks of B.S.E. in the U.S., with nothing more than the cattle to sheep ratio count, and the geographical locations of herds and flocks. That's all the evidence they can come up with, in the next 24 pages.
Something else I find odd, page 16;
"In the United Kingdom there is much concern for a specific continuous rendering technology which uses lower temperatures and accounts for 25 percent of total output. This technology was _originally_ designed and imported from the United States. However, the specific application in the production process is _believed_ to be different in the two countries."
A few more factors to consider, page 15;
"Figure 26 compares animal protein production for the two countries. The calculations are based on slaughter numbers, fallen stock estimates, and product yield coefficients. This approach is used due to variation of up to 80 percent from different reported sources. At 3.6 million tons, the United States produces 8 times more animal rendered product than the United Kingdom."
"The risk of introducing the BSE agent through sheep meat and bone meal is more acute in both relative and absolute terms in the United Kingdom (Figures 27 and 28). Note that sheep meat and bone meal accounts for 14 percent, or 61 thousand tons, in the United Kingdom versus 0.6 percent or 22 thousand tons in the United States. For sheep greater than 1 year, this is less than one-tenth of one percent of the United States supply."
"The potential risk of amplification of the BSE agent through cattle meat and bone meal is much greater in the United States where it accounts for 59 percent of total product or almost 5 times more than the total amount of rendered product in the United Kingdom."
Considering, it would only take _one_ scrapie infected sheep to contaminate the feed. Considering Scrapie has run rampant in the U.S. for years, as of Aug. 1999, 950 scrapie infected flocks. Also, Considering only one quarter spoonful of scrapie infected material is lethal to a cow.
Considering all this, the sheep to cow ration is meaningless. As I said, it's 24 pages of B.S.e.
To be continued...
Terry S. Singeltary Sr. P.O. Box Bacliff, Texas USA
Competing interests: No competing interests
FRIDAY, NOVEMBER 08, 2019
EFSA Panel on Biological Hazards (BIOHAZ) Update on chronic wasting disease (CWD) III
***> cattle, pigs, sheep, cwd, tse, prion, oh my!
***> In contrast, cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions but no natural CWD infections in cattle have been reported (Sigurdson, 2008; Hamir et al., 2006).
Sheep and cattle may be exposed to CWD via common grazing areas with affected deer but so far, appear to be poorly susceptible to mule deer CWD (Sigurdson, 2008). In contrast, cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions but no natural CWD infections in cattle have been reported (Sigurdson, 2008; Hamir et al., 2006). It is not known how susceptible humans are to CWD but given that the prion can be present in muscle, it is likely that humans have been exposed to the agent via consumption of venison (Sigurdson, 2008). Initial experimental research suggests that human susceptibility to CWD is low and there may be a robust species barrier for CWD transmission to humans (Sigurdson, 2008), however the risk appetite for a public health threat may still find this level unacceptable.
cwd scrapie pigs oral routes
***> However, at 51 months of incubation or greater, 5 animals were positive by one or more diagnostic methods. Furthermore, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study) suggesting that swine are potential hosts for the agent of scrapie. <***
>*** Although the current U.S. feed ban is based on keeping tissues from TSE infected cattle from contaminating animal feed, swine rations in the U.S. could contain animal derived components including materials from scrapie infected sheep and goats. These results indicating the susceptibility of pigs to sheep scrapie, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health. <***
***> Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 5="" 6="" at="" by="" detected="" eia.="" examined="" group="" in="" intracranial="" least="" lymphoid="" month="" months="" of="" one="" pigs="" positive="" prpsc="" quic="" the="" tissues="" was="">6 months group, 5/6 pigs in the oral <6 4="" and="" group="" months="" oral="">6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%).
***> Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
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
snip.....
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.
snip.....
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. snip..... 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).
snip.....
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. snip..... 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.
snip.....
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.
snip.....
***> READ THIS VERY, VERY, CAREFULLY, AUGUST 1997 MAD COW FEED BAN WAS A SHAM, AS I HAVE STATED SINCE 1997!
3 FAILSAFES THE FDA ET AL PREACHED AS IF IT WERE THE GOSPEL, IN TERMS OF MAD COW BSE DISEASE IN USA, AND WHY IT IS/WAS/NOT A PROBLEM FOR THE USA, and those are;
BSE TESTING (failed terribly and proven to be a sham)
BSE SURVEILLANCE (failed terribly and proven to be a sham)
BSE 589.2001 FEED REGULATIONS (another colossal failure, and proven to be a sham)
these are facts folks. trump et al just admitted it with the feed ban.
see;
FDA Reports on VFD Compliance
John Maday
August 30, 2019 09:46 AM VFD-Form 007 (640x427)
Before and after the current Veterinary Feed Directive rules took full effect in January, 2017, the FDA focused primarily on education and outreach. ( John Maday ) Before and after the current Veterinary Feed Directive (VFD) rules took full effect in January, 2017, the FDA focused primarily on education and outreach to help feed mills, veterinarians and producers understand and comply with the requirements. Since then, FDA has gradually increased the number of VFD inspections and initiated enforcement actions when necessary. On August 29, FDA released its first report on inspection and compliance activities. The report, titled “Summary Assessment of Veterinary Feed Directive Compliance Activities Conducted in Fiscal Years 2016 – 2018,” is available online.
SUNDAY, SEPTEMBER 1, 2019
***> FDA Reports on VFD Compliance
TUESDAY, APRIL 18, 2017
*** EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP ***
FRIDAY, OCTOBER 25, 2019
Experts testify United States is underprepared for bioterrorism threats Transmissible Spongiform Encephalopathy TSE Prion disease
TUESDAY, OCTOBER 29, 2019America BSE 589.2001 FEED REGULATIONS, BSE SURVEILLANCE, BSE TESTING, and CJD TSE Prion
=============================
FRIDAY, DECEMBER 14, 2012
Susceptibility of domestic cats to chronic wasting disease
Candace K. Mathiason1,#, Amy V. Nalls1, Davis M. Seelig1, Susan L. Kraft2, Kevin Carnes2, Kelly R. Anderson1, Jeanette Hayes-Klug1 and Edward A. Hoover1
+ Author Affiliations
1Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523 2Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523
ABSTRACT
Domestic and non-domestic cats have been shown to be susceptible to feline spongiform encephalopathy (FSE), almost certainly caused by consumption of bovine spongiform encephalopathy (BSE)-contaminated meat. Because domestic and free-ranging non-domestic felids scavenge cervid carcasses, including those in areas affected by chronic wasting disease (CWD), we evaluated the susceptibility of the domestic cat (Felis catus) to CWD infection experimentally. Cohorts of n=5 cats each were inoculated intracerebrally (IC) or orally (PO) with CWD-infected deer brain. At 40 and 42 months post inoculation, two IC-inoculated cats developed signs consistent with prion disease including a stilted gait, weight loss, anorexia, polydipsia, patterned motor behaviors, head and tail tremors and ataxia, and progressed to terminal disease within 5 months. Brains from these two cats were pooled and inoculated into cohorts of cats by IC, PO, and IP/SQ (intraperitoneal/subcutaneous) routes. Upon sub-passage, feline CWD was transmitted to all IC-inoculated cats with a decreased incubation period of 23-27 months. Feline-adapted CWD (FelCWD) was demonstrated in the brains of all the affected cats by western blot and immunohistochemical analysis. Magnetic resonance imaging revealed abnormalities in clinically ill cats, which included multifocal T2 FLAIR signal hyperintensities, ventricular size increases, prominent sulci and white matter tract cavitation. Currently, 3 of 4 IP/SQ and 2 of 4 PO secondary passage inoculated cats have developed abnormal behavior patterns consistent with the early stage of feline CWD. These results demonstrate that CWD can be transmitted and adapted to the domestic cat, thus raising the issue of potential cervid-to-feline transmission in nature.
FOOTNOTES
↵# To whom correspondence should be addressed. candace.mathiason@colostate.edu, 1619 Campus Delivery, Fort Collins, CO 80523-1619, 970 491-3975
Copyright © 2012, American Society for Microbiology. All Rights Reserved.
HOWEVER, why ignore the old science and transmission studies to date ???
Species Born Onset/Died
Ocelot May 1987 Mar 1994 Ocelot Jul 1980 Oct 1995 Puma 1986 May 1991 Puma 1980 May 1995 Puma 1978 May 1995 Lion Nov 1986 Dec 1998 Tiger 1981 Dec 1995 Tiger Feb 1983 Oct 1998 Ankole 1987 May 1995 Ankole 1986 Feb 1991 Bison 1989/90 Oct 1996
Maff data on 15 May 99
kudu 6 gemsbok 1 nyala 1 oryx 2 eland 6 cheetah 9 puma 3 tiger 2 ocelot 2 bison 1 ankole 2 lion 1
Feline Spongiform Encephalopathy (FSE) FSE was first identified in the UK in 1990. Most cases have been reported in the UK, where the epidemic has been consistent with that of the BSE epidemic. Some other countries (e.g. Norway, Liechtenstein and France) have also reported cases.
Most cases have been reported in domestic cats but there have also been cases in captive exotic cats (e.g. Cheetah, Lion, Asian leopard cat, Ocelot, Puma and Tiger). The disease is characterised by progressive nervous signs, including ataxia, hyper-reactivity and behavioural changes and is fatal.
The chemical and biological properties of the infectious agent are identical to those of the BSE and vCJD agents. These findings support the hypothesis that the FSE epidemic resulted from the consumption of food contaminated with the BSE agent.
The FSE epidemic has declined as a result of tight controls on the disposal of specified risk material and other animal by-products.
References: Leggett, M.M. et al.(1990) A spongiform encephalopathy in a cat. Veterinary Record. 127. 586-588
Synge, B.A. et al. (1991) Spongiform encephalopathy in a Scottish cat. Veterinary Record. 129. 320
Wyatt, J. M. et al. (1991) Naturally occurring scrapie-like spongiform encephalopathy in five domestic cats. Veterinary Record. 129. 233.
Gruffydd-Jones, T. J.et al.. (1991) Feline spongiform encephalopathy. J. Small Animal Practice. 33. 471-476.
Pearson, G. R. et al. (1992) Feline spongiform encephalopathy: fibril and PrP studies. Veterinary Record. 131. 307-310.
Willoughby, K. et al. (1992) Spongiform encephalopathy in a captive puma (Felis concolor). Veterinary Record. 131. 431-434.
Fraser, H. et al. (1994) Transmission of feline spongiform encephalopathy to mice. Veterinary Record 134. 449.
Bratberg, B. et al. (1995) Feline spongiform encephalopathy in a cat in Norway. Veterinary Record 136. 444
Baron, T. et al. (1997) Spongiform encephalopathy in an imported cheetah in France. Veterinary Record 141. 270-271
Zanusso, G et al. (1998) Simultaneous occurrence of spongiform encephalopathy in a man and his cat in Italy. Lancet, V352, N9134, OCT 3, Pp 1116-1117.
Ryder, S.J. et al. (2001) Inconsistent detection of PrP in extraneural tissues of cats with feline spongiform encephalopathy. Veterinary Record 146. 437-441
Kelly, D.F. et al. (2005) Neuropathological findings in cats with clinically suspect but histologically unconfirmed feline spongiform encephalopathy. Veterinary Record 156. 472-477.
TSEs in Exotic Ruminants TSEs have been detected in exotic ruminants in UK zoos since 1986. These include antelopes (Eland, Gemsbok, Arabian and Scimitar oryx, Nyala and Kudu), Ankole cattle and Bison. With hindsight the 1986 case in a Nyala was diagnosed before the first case of BSE was identified. The TSE cases in exotic ruminants had a younger onset age and a shorter clinical duration compared to that in cattle with BSE. All the cases appear to be linked to the BSE epidemic via the consumption of feed contaminated with the BSE agent. The epidemic has declined as a result of tight controls on feeding mammalian meat and bone meal to susceptible animals, particularly from August 1996.
References: Jeffrey, M. and Wells, G.A.H, (1988) Spongiform encephalopathy in a nyala (Tragelaphus angasi). Vet.Path. 25. 398-399
Kirkwood, J.K. et al (1990) Spongiform encephalopathy in an Arabian oryx (Oryx leucoryx) and a Greater kudu (Tragelaphus strepsiceros) Veterinary Record 127. 418-429.
Kirkwood, J.K. (1993) Spongiform encephalopathy in a herd of Greater kudu (Tragelaphus strepsiceros): epidemiological observations. Veterinary Record 133. 360-364
Kirkwood, J. K. and Cunningham, A.A. (1994) Epidemiological observations on spongiform encephalopathies in captive wild animals in the British Isles. Veterinary Record. 135. 296-303.
Food and Agriculture Organisation (1998) Manual on Bovine Spongiform Encephalopathy.
TSE and Surveillance Statistics Exotic species and domestic cats November 2018
Contents Number of confirmed cases of FSE in domestic cats by year
Number of confirmed cases of FSE in domestic cats by year of birth
Number of TSEs in exotic species by year reported
Transmissible Spongiform Encephalopathies in exotic species
Number of confirmed cases of FSE in domestic cats by year Data valid to 30 November 2018 Includes one case from Guernsey Year Reported No. of cases 1988 0 1989 0 1990 12 1991 12 1992 10 1993 11 1994 16 1995 8 1996 6 1997 6 1998 4 1999 2 2000 1 2001 1 2002 0 2003 0 2004 0 2005 0 2006 0 2007 0 2008 0 2009 0 2010 0 2011 0 2012 0 2013 0 2014 0 2015 0 2016 0 2017 0 2018 0 Total 89 Year of Onset No. of cases 1988 0 1989 1 1990 16 1991 11 1992 14 1993 10 1994 14 1995 4 1996 7 1997 8 1998 1 1999 1 2000 1 2001 1 2002 0 2003 0 2004 0 2005 0 2006 0 2007 0 2008 0 2009 0 2010 0 2011 0 2012 0 2013 0 2014 0 2015 0 2016 0 2017 0 2018 0 Total 89
FSE: FIRST CONFIRMED CASE REPORTED IN PORTUGAL AND POTENTIAL MAD CAT ESCAPES LAB IN USA Date: August 9, 2007 at 2:27 pm PST
DIA-45 FELINE SPONGIFORM ENCEPHALOPATHY: FIRST CONFIRMED CASE REPORTED IN PORTUGAL
J.F. Silva1, J.J. Correia, 1 J. Ribeiro2, S. Carmo2 and L.Orge3
1 Faculdade de Medicina Veterinária (UTL), Lisbon, Portugal 2 Clínica Veterinária Ani+, Queluz, Portugal 3 Laboratório Nacional de Investigação Veterinária, Unidade de BSE, Lisbon, Portugal
Feline spongiform encephalopathy (FSE), affecting domestic and captive feline species, is a prion disease considered to be related to bovine spongiform encephalopathy (BSE). Here we report the first case diagnosed in Portugal, highlighting the neuroapthological findings. In 2004 a 9-year old intact female Siamese cat was referred with chronic progressive behavioural changes, polydipsia, gait abnormalities and episodes of hypersalivation. Clinical signs progressed to tetraparesis and dementia and euthanasia was performed. At necropsy, brain and spinal cord had no significative changes. Tissue samples from brain, cerebellum, brainstem and spinal cord were collected for histopathology and immunohistochemistry for detection of PrPres. Histology revealed neuropil and neuronal perikarion vacuolation in several areas of the central nervous system together with gliosis and cell rarefaction at the granular layer of the cerebellum. Immunohistochemical detection of PrPres showed a strong and widespread PrPres accumulation as granular and linear deposits as well as associated with some neurons. These findings are supportive of FSE. To the authors knowledge this is the first confirmed case of FSE reported in Portugal.
DOCKET-- 03D-0186 -- FDA Issues Draft Guidance on Use of Material From Deer and Elk in Animal Feed; Availability
Date: Fri, 16 May 2003 11:47:37 –0500
EMC 1 Terry S. Singeltary Sr. Vol #: 1
IN CONFIDENCE CJD TO CATS...
It should be noted that under experimental conditions cats succumb to an encephalopathy after intracerebral inoculation of material derived from patients affected with Creutzfeldt-Jakob Disease.
FELINE SPONGIFORM ENCEPHALOPATHY FSE
WEDNESDAY, JANUARY 2, 2019
canine and feline spongiform encephalopathy tse prion 2019 update
MONDAY, AUGUST 8, 2011 Susceptibility of Domestic Cats to CWD Infection Oral.29: Susceptibility of Domestic Cats to CWD Infection
Amy Nalls, Nicholas J. Haley, Jeanette Hayes-Klug, Kelly Anderson, Davis M. Seelig, Dan S. Bucy, Susan L. Kraft, Edward A. Hoover and Candace K. Mathiason†
Colorado State University; Fort Collins, CO USA†Presenting author; Email: ckm@lamar.colostate.edu
Domestic and non-domestic cats have been shown to be susceptible to one prion disease, feline spongiform encephalopathy (FSE), thought to be transmitted through consumption of bovine spongiform encephalopathy (BSE) contaminated meat. Because domestic and free ranging felids scavenge cervid carcasses, including those in CWD affected areas, we evaluated the susceptibility of domestic cats to CWD infection experimentally. Groups of n = 5 cats each were inoculated either intracerebrally (IC) or orally (PO) with CWD deer brain homogenate. Between 40–43 months following IC inoculation, two cats developed mild but progressive symptoms including weight loss, anorexia, polydipsia, patterned motor behaviors and ataxia—ultimately mandating euthanasia. Magnetic resonance imaging (MRI) on the brain of one of these animals (vs. two age-matched controls) performed just before euthanasia revealed increased ventricular system volume, more prominent sulci, and T2 hyperintensity deep in the white matter of the frontal hemisphere and in cortical grey distributed through the brain, likely representing inflammation or gliosis. PrPRES and widely distributed peri-neuronal vacuoles were demonstrated in the brains of both animals by immunodetection assays. No clinical signs of TSE have been detected in the remaining primary passage cats after 80 months pi. Feline-adapted CWD was sub-passaged into groups (n=4 or 5) of cats by IC, PO, and IP/SQ routes. Currently, at 22 months pi, all five IC inoculated cats are demonstrating abnormal behavior including increasing aggressiveness, pacing, and hyper responsiveness. Two of these cats have developed rear limb ataxia. Although the limited data from this ongoing study must be considered preliminary, they raise the potential for cervid-to-feline transmission in nature.
Monday, August 8, 2011
Susceptibility of Domestic Cats to CWD Infection
UPDATED DATA ON 2ND CWD STRAIN
Wednesday, September 08, 2010 CWD PRION CONGRESS SEPTEMBER 8-11 2010
Monday, February 14, 2011
THE ROLE OF PREDATION IN DISEASE CONTROL: A COMPARISON OF SELECTIVE AND NONSELECTIVE REMOVAL ON PRION DISEASE DYNAMICS IN DEER
NO, NO, NOT NO, BUT HELL NO !
Journal of Wildlife Diseases, 47(1), 2011, pp. 78-93 © Wildlife Disease Association 2011
***> NEW TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION DISEASE (MAD CAMEL DISEASE) IN A NEW SPECIES <***
NEW OUTBREAK OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION DISEASE IN A NEW SPECIES
Subject: Prion Disease in Dromedary Camels, Algeria
Our identification of this prion disease in a geographically widespread livestock species requires urgent enforcement of surveillance and assessment of the potential risks to human and animal health.
Wednesday, May 30, 2018
Dromedary camels in northern Africa have a neurodegenerative prion disease that may have originated decades ago
***> IMPORTS AND EXPORTS <***
SEE MASSIVE AMOUNTS OF BANNED ANIMAL PROTEIN AKA MAD COW FEED IN COMMERCE USA DECADES AFTER POST BAN
Thursday, August 1, 2019
Camel prion disease detected in Tunisian camels
FRIDAY, JULY 26, 2019
Chronic Wasting Disease in Cervids: Implications for Prion Transmission to Humans and Other Animal Species
MONDAY, JUNE 24, 2019
APHIS, FSIS, USDA, FDA, Transmissible Spongiform Encephalopathy TSE, BSE, CWD, Scrapie, Camel TSE Prion Disease, CJD Humans
WEDNESDAY, JULY 31, 2019
The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L
TUESDAY, JULY 30, 2019
Guidelines for reporting surveillance data on Transmissible Spongiform Encephalopathies (TSE) in the EU within the framework of Regulation (EC) No 999/2001 APPROVED: 9 July 2019
PLEASE READ THE LATEST JUST OUT ON CWD TSE PRION FROM EFSA SCIENTISTS...terry
FRIDAY, NOVEMBER 08, 2019
***> EFSA Panel on Biological Hazards (BIOHAZ) Update on chronic wasting disease (CWD) III
8. Consumption of forage grown on contaminated soil
I & II Prions can persist on the leaf apparatus directly soiled with contaminated materials; plants, grown on contaminated soils, can absorb the prions from topsoil and transfer them to the leaves. By PMCA prions have been shown to bind tightly to roots and leaves when exposed to either brain homogenate or excreta (Pritzkow et al., 2015)
Pritzkow et al. (2015)
other F N
1% increase in the clay-sized particle content in soils within the approximate home range of an individual deer increased its odds of infection by up to 8.9% Walter et al. (2011) cross-s D N
In northern Europe, the collection and marketing of potentially contaminated lichens is also widespread for the feeding of farmed deer (VKM, 2017; VKM et al., 2018) VKM (VKM, 2017; VKM et al., 2018)
review F Y
WEDNESDAY, OCTOBER 16, 2019
***> Australia Assessment of bulk wheat from Canada Part B: Animal biosecurity risk advice, CWD TSE Prion concerns are mounting
MONDAY, NOVEMBER 04, 2019
Legislators legislating, or throwing away your money for battling cwd tse prion, State Rep. Steve Green, R-Fosston more money to deer farms for antibiotics?
THE tse prion aka mad cow type disease is not your normal pathogen.
The TSE prion disease survives ashing to 600 degrees celsius, that’s around 1112 degrees farenheit.
you cannot cook the TSE prion disease out of meat.
you can take the ash and mix it with saline and inject that ash into a mouse, and the mouse will go down with TSE.
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production as well.
the TSE prion agent also survives Simulated Wastewater Treatment Processes.
IN fact, you should also know that the TSE Prion agent will survive in the environment for years, if not decades.
you can bury it and it will not go away.
The TSE agent is capable of infected your water table i.e. Detection of protease-resistant cervid prion protein in water from a CWD-endemic area.
it’s not your ordinary pathogen you can just cook it out and be done with.
***> that’s what’s so worrisome about Iatrogenic mode of transmission, a simple autoclave will not kill this TSE prion agent.
1: J Neurol Neurosurg Psychiatry 1994 Jun;57(6):757-8
***> Transmission of Creutzfeldt-Jakob disease to a chimpanzee by electrodes contaminated during neurosurgery.
Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC.
Laboratory of Central Nervous System Studies, National Institute of
Neurological Disorders and Stroke, National Institutes of Health,
Bethesda, MD 20892.
Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.
PMID: 8006664 [PubMed - indexed for MEDLINE]
2018 - 2019
***> This is very likely to have parallels with control efforts for CWD in cervids.
Rapid recontamination of a farm building occurs after attempted prion removal
Kevin Christopher Gough, BSc (Hons), PhD1, Claire Alison Baker, BSc (Hons)2, Steve Hawkins, MIBiol3, Hugh Simmons, BVSc, MRCVS, MBA, MA3, Timm Konold, DrMedVet, PhD, MRCVS3 and Ben Charles Maddison, BSc (Hons), PhD2
Abstract
The transmissible spongiform encephalopathy scrapie of sheep/goats and chronic wasting disease of cervids are associated with environmental reservoirs of infectivity.
Preventing environmental prions acting as a source of infectivity to healthy animals is of major concern to farms that have had outbreaks of scrapie and also to the health management of wild and farmed cervids.
Here, an efficient scrapie decontamination protocol was applied to a farm with high levels of environmental contamination with the scrapie agent.
Post-decontamination, no prion material was detected within samples taken from the farm buildings as determined using a sensitive in vitro replication assay (sPMCA).
A bioassay consisting of 25 newborn lambs of highly susceptible prion protein genotype VRQ/VRQ introduced into this decontaminated barn was carried out in addition to sampling and analysis of dust samples that were collected during the bioassay.
Twenty-four of the animals examined by immunohistochemical analysis of lymphatic tissues were scrapie-positive during the bioassay, samples of dust collected within the barn were positive by month 3.
The data illustrates the difficulty in decontaminating farm buildings from scrapie, and demonstrates the likely contribution of farm dust to the recontamination of these environments to levels that are capable of causing disease.
snip...
As in the authors' previous study,12 the decontamination of this sheep barn was not effective at removing scrapie infectivity, and despite the extra measures brought into this study (more effective chemical treatment and removal of sources of dust) the overall rates of disease transmission mirror previous results on this farm. With such apparently effective decontamination (assuming that at least some sPMCA seeding ability is coincident with infectivity), how was infectivity able to persist within the environment and where does infectivity reside? Dust samples were collected in both the bioassay barn and also a barn subject to the same decontamination regime within the same farm (but remaining unoccupied). Within both of these barns dust had accumulated for three months that was able to seed sPMCA, indicating the accumulation of scrapie-containing material that was independent of the presence of sheep that may have been incubating and possibly shedding low amounts of infectivity.
This study clearly demonstrates the difficulty in removing scrapie infectivity from the farm environment. Practical and effective prion decontamination methods are still urgently required for decontamination of scrapie infectivity from farms that have had cases of scrapie and this is particularly relevant for scrapiepositive goatherds, which currently have limited genetic resistance to scrapie within commercial breeds.24 This is very likely to have parallels with control efforts for CWD in cervids.
Acknowledgements The authors thank the APHA farm staff, Tony Duarte, Olly Roberts and Margaret Newlands for preparation of the sheep pens and animal husbandry during the study. The authors also thank the APHA pathology team for RAMALT and postmortem examination.
Funding This study was funded by DEFRA within project SE1865.
Competing interests None declared.
Saturday, January 5, 2019
Rapid recontamination of a farm building occurs after attempted prion removal
THURSDAY, FEBRUARY 28, 2019
BSE infectivity survives burial for five years with only limited spread
***> CONGRESSIONAL ABSTRACTS PRION CONFERENCE 2018
P69 Experimental transmission of CWD from white-tailed deer to co-housed reindeer
Mitchell G (1), Walther I (1), Staskevicius A (1), Soutyrine A (1), Balachandran A (1)
(1) National & OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada.
Chronic wasting disease (CWD) continues to be detected in wild and farmed cervid populations of North America, affecting predominantly white-tailed deer, mule deer and elk. Extensive herds of wild caribou exist in northern regions of Canada, although surveillance has not detected the presence of CWD in this population. Oral experimental transmission has demonstrated that reindeer, a species closely related to caribou, are susceptible to CWD. Recently, CWD was detected for the first time in Europe, in wild Norwegian reindeer, advancing the possibility that caribou in North America could also become infected. Given the potential overlap in habitat between wild CWD-infected cervids and wild caribou herds in Canada, we sought to investigate the horizontal transmissibility of CWD from white-tailed deer to reindeer.
Two white-tailed deer were orally inoculated with a brain homogenate prepared from a farmed Canadian white-tailed deer previously diagnosed with CWD. Two reindeer, with no history of exposure to CWD, were housed in the same enclosure as the white-tailed deer, 3.5 months after the deer were orally inoculated. The white-tailed deer developed clinical signs consistent with CWD beginning at 15.2 and 21 months post-inoculation (mpi), and were euthanized at 18.7 and 23.1 mpi, respectively. Confirmatory testing by immunohistochemistry (IHC) and western blot demonstrated widespread aggregates of pathological prion protein (PrPCWD) in the central nervous system and lymphoid tissues of both inoculated white-tailed deer. Both reindeer were subjected to recto-anal mucosal associated lymphoid tissue (RAMALT) biopsy at 20 months post-exposure (mpe) to the white-tailed deer. The biopsy from one reindeer contained PrPCWD confirmed by IHC. This reindeer displayed only subtle clinical evidence of disease prior to a rapid decline in condition requiring euthanasia at 22.5 mpe. Analysis of tissues from this reindeer by IHC revealed widespread PrPCWD deposition, predominantly in central nervous system and lymphoreticular tissues. Western blot molecular profiles were similar between both orally inoculated white-tailed deer and the CWD positive reindeer. Despite sharing the same enclosure, the other reindeer was RAMALT negative at 20 mpe, and PrPCWD was not detected in brainstem and lymphoid tissues following necropsy at 35 mpe. Sequencing of the prion protein gene from both reindeer revealed differences at several codons, which may have influenced susceptibility to infection.
Natural transmission of CWD occurs relatively efficiently amongst cervids, supporting the expanding geographic distribution of disease and the potential for transmission to previously naive populations. The efficient horizontal transmission of CWD from white-tailed deer to reindeer observed here highlights the potential for reindeer to become infected if exposed to other cervids or environments infected with CWD.
***> Infectious agent of sheep scrapie may persist in the environment for at least 16 years
***> Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded.
Gudmundur Georgsson,1 Sigurdur Sigurdarson2 and Paul Brown3
Correspondence
Gudmundur Georgsson ggeorgs@hi.is
1 Institute for Experimental Pathology, University of Iceland, Keldur v/vesturlandsveg, IS-112 Reykjavı´k, Iceland
2 Laboratory of the Chief Veterinary Officer, Keldur, Iceland
3 Bethesda, Maryland, USA
Received 7 March 2006 Accepted 6 August 2006
In 1978, a rigorous programme was implemented to stop the spread of, and subsequently eradicate, sheep scrapie in Iceland. Affected flocks were culled, premises were disinfected and, after 2–3 years, restocked with lambs from scrapie-free areas. Between 1978 and 2004, scrapie recurred on 33 farms. Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded. Of special interest was one farm with a small, completely self-contained flock where scrapie recurred 18 years after culling, 2 years after some lambs had been housed in an old sheephouse that had never been disinfected. Epidemiological investigation established with near certitude that the disease had not been introduced from the outside and it is concluded that the agent may have persisted in the old sheep-house for at least 16 years.
TITLE: PATHOLOGICAL FEATURES OF CHRONIC WASTING DISEASE IN REINDEER AND DEMONSTRATION OF HORIZONTAL TRANSMISSION
*** DECEMBER 2016 CDC EMERGING INFECTIOUS DISEASE JOURNAL CWD HORIZONTAL TRANSMISSION
SEE;
Back around 2000, 2001, or so, I was corresponding with officials abroad during the bse inquiry, passing info back and forth, and some officials from here inside USDA aphis FSIS et al. In fact helped me get into the USA 50 state emergency BSE conference call way back. That one was a doozy. But I always remember what “deep throat” I never knew who they were, but I never forgot;
Some unofficial information from a source on the inside looking out -
Confidential!!!!
As early as 1992-3 there had been long studies conducted on small pastures containing scrapie infected sheep at the sheep research station associated with the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are documented...I don't know. But personal recounts both heard and recorded in a daily journal indicate that leaving the pastures free and replacing the topsoil completely at least 2 feet of thickness each year for SEVEN years....and then when very clean (proven scrapie free) sheep were placed on these small pastures.... the new sheep also broke out with scrapie and passed it to offspring. I am not sure that TSE contaminated ground could ever be free of the agent!! A very frightening revelation!!!
---end personal email---end...tss
Infectivity surviving ashing to 600*C is (in my opinion) degradable but infective. based on Bown & Gajdusek, (1991), landfill and burial may be assumed to have a reduction factor of 98% (i.e. a factor of 50) over 3 years. CJD-infected brain-tissue remained infectious after storing at room-temperature for 22 months (Tateishi et al, 1988). Scrapie agent is known to remain viable after at least 30 months of desiccation (Wilson et al, 1950). and pastures that had been grazed by scrapie-infected sheep still appeared to be contaminated with scrapie agent three years after they were last occupied by sheep (Palsson, 1979).
Dr. Paul Brown Scrapie Soil Test BSE Inquiry Document
THURSDAY, FEBRUARY 28, 2019
BSE infectivity survives burial for five years with only limited spread
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.
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production
Detection of protease-resistant cervid prion protein in water from a CWD-endemic area
A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing
Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals
PPo4-4:
Survival and Limited Spread of TSE Infectivity after Burial
Discussion Classical scrapie is an environmentally transmissible disease because it has been reported in naïve, supposedly previously unexposed sheep placed in pastures formerly occupied by scrapie-infected sheep (4, 19, 20).
Although the vector for disease transmission is not known, soil is likely to be an important reservoir for prions (2) where – based on studies in rodents – prions can adhere to minerals as a biologically active form (21) and remain infectious for more than 2 years (22).
Similarly, chronic wasting disease (CWD) has re-occurred in mule deer housed in paddocks used by infected deer 2 years earlier, which was assumed to be through foraging and soil consumption (23).
Our study suggested that the risk of acquiring scrapie infection was greater through exposure to contaminated wooden, plastic, and metal surfaces via water or food troughs, fencing, and hurdles than through grazing.
Drinking from a water trough used by the scrapie flock was sufficient to cause infection in sheep in a clean building.
Exposure to fences and other objects used for rubbing also led to infection, which supported the hypothesis that skin may be a vector for disease transmission (9).
The risk of these objects to cause infection was further demonstrated when 87% of 23 sheep presented with PrPSc in lymphoid tissue after grazing on one of the paddocks, which contained metal hurdles, a metal lamb creep and a water trough in contact with the scrapie flock up to 8 weeks earlier, whereas no infection had been demonstrated previously in sheep grazing on this paddock, when equipped with new fencing and field furniture.
When the contaminated furniture and fencing were removed, the infection rate dropped significantly to 8% of 12 sheep, with soil of the paddock as the most likely source of infection caused by shedding of prions from the scrapie-infected sheep in this paddock up to a week earlier.
This study also indicated that the level of contamination of field furniture sufficient to cause infection was dependent on two factors: stage of incubation period and time of last use by scrapie-infected sheep.
Drinking from a water trough that had been used by scrapie sheep in the predominantly pre-clinical phase did not appear to cause infection, whereas infection was shown in sheep drinking from the water trough used by scrapie sheep in the later stage of the disease.
It is possible that contamination occurred through shedding of prions in saliva, which may have contaminated the surface of the water trough and subsequently the water when it was refilled.
Contamination appeared to be sufficient to cause infection only if the trough was in contact with sheep that included clinical cases.
Indeed, there is an increased risk of bodily fluid infectivity with disease progression in scrapie (24) and CWD (25) based on PrPSc detection by sPMCA.
Although ultraviolet light and heat under natural conditions do not inactivate prions (26), furniture in contact with the scrapie flock, which was assumed to be sufficiently contaminated to cause infection, did not act as vector for disease if not used for 18 months, which suggest that the weathering process alone was sufficient to inactivate prions.
PrPSc detection by sPMCA is increasingly used as a surrogate for infectivity measurements by bioassay in sheep or mice.
In this reported study, however, the levels of PrPSc present in the environment were below the limit of detection of the sPMCA method, yet were still sufficient to cause infection of in-contact animals.
In the present study, the outdoor objects were removed from the infected flock 8 weeks prior to sampling and were positive by sPMCA at very low levels (2 out of 37 reactions).
As this sPMCA assay also yielded 2 positive reactions out of 139 in samples from the scrapie-free farm, the sPMCA assay could not detect PrPSc on any of the objects above the background of the assay.
False positive reactions with sPMCA at a low frequency associated with de novo formation of infectious prions have been reported (27, 28).
This is in contrast to our previous study where we demonstrated that outdoor objects that had been in contact with the scrapie-infected flock up to 20 days prior to sampling harbored PrPSc that was detectable by sPMCA analysis [4 out of 15 reactions (12)] and was significantly more positive by the assay compared to analogous samples from the scrapie-free farm.
This discrepancy could be due to the use of a different sPMCA substrate between the studies that may alter the efficiency of amplification of the environmental PrPSc.
In addition, the present study had a longer timeframe between the objects being in contact with the infected flock and sampling, which may affect the levels of extractable PrPSc.
Alternatively, there may be potentially patchy contamination of this furniture with PrPSc, which may have been missed by swabbing.
The failure of sPMCA to detect CWD-associated PrP in saliva from clinically affected deer despite confirmation of infectivity in saliva-inoculated transgenic mice was associated with as yet unidentified inhibitors in saliva (29), and it is possible that the sensitivity of sPMCA is affected by other substances in the tested material.
In addition, sampling of amplifiable PrPSc and subsequent detection by sPMCA may be more difficult from furniture exposed to weather, which is supported by the observation that PrPSc was detected by sPMCA more frequently in indoor than outdoor furniture (12).
A recent experimental study has demonstrated that repeated cycles of drying and wetting of prion-contaminated soil, equivalent to what is expected under natural weathering conditions, could reduce PMCA amplification efficiency and extend the incubation period in hamsters inoculated with soil samples (30).
This seems to apply also to this study even though the reduction in infectivity was more dramatic in the sPMCA assays than in the sheep model.
Sheep were not kept until clinical end-point, which would have enabled us to compare incubation periods, but the lack of infection in sheep exposed to furniture that had not been in contact with scrapie sheep for a longer time period supports the hypothesis that prion degradation and subsequent loss of infectivity occurs even under natural conditions.
In conclusion, the results in the current study indicate that removal of furniture that had been in contact with scrapie-infected animals should be recommended, particularly since cleaning and decontamination may not effectively remove scrapie infectivity (31), even though infectivity declines considerably if the pasture and the field furniture have not been in contact with scrapie-infected sheep for several months. As sPMCA failed to detect PrPSc in furniture that was subjected to weathering, even though exposure led to infection in sheep, this method may not always be reliable in predicting the risk of scrapie infection through environmental contamination.
These results suggest that the VRQ/VRQ sheep model may be more sensitive than sPMCA for the detection of environmentally associated scrapie, and suggest that extremely low levels of scrapie contamination are able to cause infection in susceptible sheep genotypes.
Keywords: classical scrapie, prion, transmissible spongiform encephalopathy, sheep, field furniture, reservoir, serial protein misfolding cyclic amplification
Wednesday, December 16, 2015
*** Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission ***
WEDNESDAY, MARCH 13, 2019
CWD, TSE, PRION, MATERNAL mother to offspring, testes, epididymis, seminal fluid, and blood
Subject: Prion 2019 Conference
See full Prion 2019 Conference Abstracts
see scientific program and follow the cwd studies here;
Thursday, May 23, 2019
Prion 2019 Emerging Concepts CWD, BSE, SCRAPIE, CJD, SCIENTIFIC PROGRAM Schedule and Abstracts
FRIDAY, MAY 24, 2019
Assessing chronic wasting disease strain differences in free-ranging cervids across the United States
MONDAY, MAY 20, 2019
APHIS, USDA, Announces the Finalized Chronic Wasting Disease Herd Certification Program Standards Singeltary Submissions
SUNDAY, JULY 14, 2019
Korea Chronic Wasting Disease CWD TSE Prion additional cases were observed in red deer, sika deer, and their crossbred deer in 2010 and 2016, beyond that, anyone's guess
Korea Chronic Wasting Disease CWD TSE Prion additional cases were observed in red deer, sika deer, and their crossbred deer in 2010 and 2016
In Korea, CWD was only confirmed in elk in 2001, 2004, and 2005 [13]; however, additional cases were observed in red deer, sika deer, and their crossbred deer in 2010 and 2016 [14]. Therefore, it is important to prevent CWD recurrence in the Republic of Korea, and farmers that have experienced a CWD outbreak are required to disinfect the farm before reintroducing the cervids. Thus, farmers require a disinfectant solution that is marketed and readily available to effectively inactivate prions.
[14] Sohn HJ, Roh IS, Kim HJ, et al. Epidemiology of chronic wasting disease in Korea. Prion. 2106;10 (supp1):S16–S17
WS-03: Epidemiology of chronic wasting disease in Korea
Hyun Joo Sohn
In Soon Roh
Hyo Jin Kim
Tae Young Suh
Kyung Je Park
Hoo Chang Park
Byounghan Kim
Foreign Animal Disease Division (FADD), Animal and Plant Quarantine Agency (QIA), Gimcheon, Korea
Transmissible spongiform encephalopathy (TSE) is a fatal neurodegenerative disorder, which is so-called as prion diseases due to the causative agents (PrPSc). TSEs are believed to be due to the template-directed accumulation of disease-associated prion protein, generally designated PrPSc. Based on export information of Chronic wasting disease (CWD) suspected elk from Canada to Korea, CWD surveilance program was initiated by the Ministry of Agriculture, Food and Rural Affairs (MAFRA) in 2001. CWD control measures included stamping out of all animals in the affected farm, and through cleaning and disinfection of the premises. In addition, nationwide clinical surveillance of Korean native cervid 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. On 2010, 6 elks, 7 sika deer, one red deer and 5 cross-breeds were confirmed as positive. Further epidemiological investigations showed that these CWD outbreaks were linked to the importation of elks from Canada in 1994 based on circumstantial evidences. CWD is the prion disease that is known spread horizontally. The experimental studies have shown that PrPCWD is capable of transmitting CWD through saliva and blood. We conducted sPMCA and animal biosassy using contaminated soils in the playground of farm 2 which considered horizontal transmission between cervid and have been confirmed infectious PrPCWD. This result suggests PrPCWD shedding in the CWD contaminated soil is progressive through the disease course.
Keywords: CWD, soil, sPMCA
Additional Cases of Chronic Wasting Disease in Imported Deer in Korea
Tae-Yung KIM1,3), Hyun-Joo SHON2), Yi-Seok JOO2), Un-Kyong MUN2), Kyung-Sun KANG3) and Yong-Soon LEE3)* 1)Animal Health Division, Ministry of Agriculture & Forestry, Kwacheon 427–760, 2)National Veterinary Research & Quarantine Service, Anyang 430–016 and 3)Department of Veterinary Public Health, College of Veterinary Medicine, Seoul National University, Seoul 151– 742, Korea (Received 21 January 2005/Accepted 27 May 2005)
ABSTRACT.
Chronic Wasting Disease (CWD), which had previously occurred only in the U.S.A. and Canada, broke out in a farm at Chungbuk, Korea from imported Canadian deer (Aug. 8, 2001). CWD distribution, through surveillance and epidemiologic investigations, was reported for 93 deer (43 from the CWD originating farm and 50 imported with the CWD originating farm’s deer) out of 144 deer (72 from the CWD originating farm and 72 imported with the CWD originating farm’s deer) that were breeding at 30 different farms. On Oct. 4 and Oct. 8, 2001, additional cases of CWD were investigated. As a result of slaughtering cohabitating deer, it was verified that other imported deer from Canada were also infected with CWD. Since it was thought that this might cause horizontal transmission, 93 deer imported from Canada in 1997 and 130 cohabitating Korean deer were slaughtered and examined. There were no infected Korean deer, but CWD re-occurred on Nov. 20, 2004 and is still under investigation. KEY WORDS: Chronic Wasting Disease (CWD), horizontal transmission. J. Vet. Med. Sci. 67(8): 753–759, 2005
Strain Characterization of the Korean CWD Cases in 2001 and 2004
Yoon-Hee LEE1), Hyun-Joo SOHN1)*, Min-Jeong KIM1), Hyo-Jin KIM1), Won-Yong LEE1), Eun-Im YUN1), Dong-Seob TARK1), In-Soo CHO1) and Aru BALACHANDRAN2) 1)Animal, Plant and Fisheries Quarantine and Inspection Agency, Ministry for Food, Agriculture, Forestry and Fisheries, Anyang 430–757, Republic of Korea 2)National and OIE Reference Laboratory for Scrapie and CWD, Ottawa Laboratory Fallowfield, Ottawa, Canadian Food Inspection Agency, Ottawa, Ontario K2H 8P9, Canada (Received 22 February 2012/Accepted 14 August 2012/Published online in J-STAGE 28 August 2012)
ABSTRACT.
Chronic wasting disease (CWD) has been recognized as a naturally occurring prion disease in North American deer (Odocoileus species), Rocky Mountain elk (Cervus elaphus nelsoni) and moose (Alces alces). The disease was confirmed only in elk in the Republic of Korea in 2001, 2004 and 2005. Epidemiological investigations showed that CWD was introduced via importation of infected elk from Canada between 1994 and 1997. In spite of the increasing geographic distribution and host range of CWD, little is known about the prion strain (s) responsible for distinct outbreaks of the disease. We carried out strain characterization, using transgenic mice overexpressing elk prion protein, including clinical assessment, pathological examination and biochemical analyses, in brain tissues derived following primary through tertiary transmissions. The final incubation period was shortened to approximately 130 dpi due to adaptation. Biochemical profiles remained identical between passages. Lesion profiling in recipient mice brains showed similar patterns of vacuolation scores and intensity. It is clear that there were no biochemical or histopathological differences in Korean CWD cases in 2001 and 2004, suggesting a single strain was responsible for the outbreaks.
KEY WORDS: CWD, Republic of Korea, strain characterization. doi: 10.1292/jvms.12-0077; J. Vet. Med. Sci. 75(1): 95–98, 2013
A Case of Chronic Wasting Disease in an Elk Imported to Korea from Canada
Hyun-Joo SOHN1), Jae-Hoon KIM1)*, Kang-Seuk CHOI1), Jin-Ju NAH1), Yi-Seok JOO1), Young-Hwa JEAN1), Soo-Whan AHN1), Ok-Kyung KIM1), Dae-Yong KIM2) and Aru BALACHANDRAN3) 1)National Veterinary Research and Quarantine Service, Anyang 430–824, 2)Department of Pathology, College of Veterinary Medicine, Seoul National University, Suwon 441–744, Korea and 3)Animal Disease Research Institute, Canadian Food Inspection Agency, Nepean, Ontario, Canada (Received 13 March 2002/Accepted 8 May 2002)
ABSTRACT.
A seven-year-old male elk (Cervus elaphus nelsoni) was euthanized and necropsied after having a 3-week history of body weight loss, emaciation, excessive salivation, teeth grinding, fever, anorexia, and respiratory distress. The elk was imported into Korea from Canada on March 9, 1997. Gross pathologic findings were restricted to a diffuse fibrinous pneumonia. Microscopic lesions included mild neuronal vacuolation and spongiform change in the neuropil of selected brain stem nuclei and generalized astrocytosis. Immunohistochemistry for protease-resistant prion protein (PrPres) was positive in all brain sections but more pronounced in the section of the obex of the medulla. And the PrP res was also detected by western immunoblotting in the brain and spinal cord. All the remaining elk and deer that had been in contact with this elk were destroyed and negative for chronic wasting disease (CWD). To our knowl edge, this is the first case of CWD occurring outside of the U.S.A. and Canada.
KEY WORDS: chronic wasting disease, elk, immunohistochemistry. J. Vet. Med. Sci. 64(9): 855–858, 2002
KOREA CWD TSE Prion
CWD outbreaks in farmed animals were reported in 2001, 2004, 2005, 2010, and *2016 in the Republic of Korea.
Korean CWD was introduced by elk imported from Canada in 1997.
CWD outbreaks in farmed animals were reported in 2001, 2004, 2005, 2010, and ***2016 in the Republic of Korea.
The Korean water deer is the dominant species of wild deer in Korea, with approximately 620 thousand heads (8.0 heads/100 ha) [9].
*2016 in the Republic of Korea.
I LACK A REPORT ON THAT~!???
i have asked about it to Korea officials and scientist, with no reply to date...so, total count on Chronic Wasting Disease CWD TSE Prion in Korea, your guess is good as mine, especially through 2019, ...terry
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.
KOREA CWD TSE PRION
Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea 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.
: Corresponding author: Dr. Hyun-Joo Sohn (+82-31-467-1867, E-mail: shonhj@korea.kr) 2011 Pre-congress Workshop: TSEs in animals and their environment 5
FULL PAPER
Additional Cases of Chronic Wasting Disease in Imported Deer in Korea
Tae-Yung KIM, Hyun-Joo SHON, Yi-Seok JOO, Un-Kyong MUN, Kyung-Sun KANG, Yong-Soon LEE Author information Keywords: Chronic Wasting Disease (CWD), horizontal transmission JOURNALS FREE ACCESS 2005 Volume 67 Issue 8 Pages 753-759
Abstract
Chronic Wasting Disease (CWD), which had previously occurred only in the U.S.A. and Canada, broke out in a farm at Chungbuk, Korea from imported Canadian deer (Aug. 8, 2001). CWD distribution, through surveillance and epidemiologic investigations, was reported for 93 deer (43 from the CWD originating farm and 50 imported with the CWD originating farm's deer) out of 144 deer (72 from the CWD originating farm and 72 imported with the CWD originating farm's deer) that were breeding at 30 different farms. On Oct. 4 and Oct. 8, 2001, additional cases of CWD were investigated. As a result of slaughtering cohabitating deer, it was verified that other imported deer from Canada were also infected with CWD. Since it was thought that this might cause horizontal transmission, 93 deer imported from Canada in 1997 and 130 cohabitating Korean deer were slaughtered and examined. There were no infected Korean deer, but CWD re-occurred on Nov. 20, 2004 and is still under investigation.
snip...
DISCUSSION
Fig. 3. Present status of farms that sold or resold imported Canadian elk in 1997.
A total of 129 deer (deer/year: 27/1994, 30/1995, and 72/ 1997) were imported from the CWD originating farm in Canada, None ofthe 57 deer imported in 1994 and 1995 fell dead during the advanced surmise period, 60 months, and were confirmed to have no clinical disorders by Canadian authorities and no clinical matters examined. Korean deer were raised for 3.5 years with 144 deer imported in 1997, during which time only 9 of the imported deer became infected, Five of them were imported from the CWD affected farm in Canada and the other 4 were gathered at the CWD affected farm (SK 3 farm) for quarantine and shipped to Korea on the same boat.
It can be considered that horizontal CWD transmission took place, but it is still unclear whether only 4 of the cohabitating Canadian deer became infected. Therefore, Korean authorities should exchange further information on the number of quarantine certificates and coupons with the Canadian Communicable Disease Control Department in order to re— investigate whether only 5 deer were raised at the CWD affected farm, with the other 4 deer being raised at a CWD free farm, or whether the disease was transmitted during shipping. Furthermore, why cohabitating Korean deer were not infected by CWD is considered to be a subject for further research.
The Korean Communicable Disease Control Department did its best to prevent the spread of CWD, but failed to trace back 43 out of 144 deer imported from Canada in 1997,
CHRONIC WASTING DISEASE CASES IN KOREA 759
Among these, 25 deer were from the CWD affected farm and 18 deer were imported with the deer from the CWD affected farm (Table 5). The department is currently investigating a new case of CWD found on Nov, 20, 2004 to determine whether it is a deer that was missing in 2001, or a vertically or horizontally transmitted deer.
ACKNOWLEDGMENTS, This work was supported by the National Veterinary Research & Quarantine Service, Anyang 430-016, Korea.
REFERENCES
Strain Characterization of the Korean CWD Cases in 2001 and 2004
Yoon-Hee LEE1), Hyun-Joo SOHN1)*, Min-Jeong KIM1), Hyo-Jin KIM1), Won-Yong LEE1), Eun-Im YUN1), Dong-Seob TARK1), In-Soo CHO1) and Aru BALACHANDRAN2)
1)Animal, Plant and Fisheries Quarantine and Inspection Agency, Ministry for Food, Agriculture, Forestry and Fisheries, Anyang 430–757, Republic of Korea
2)National and OIE Reference Laboratory for Scrapie and CWD, Ottawa Laboratory Fallowfield, Ottawa, Canadian Food Inspection Agency, Ottawa, Ontario K2H 8P9, Canada
(Received 22 February 2012/Accepted 14 August 2012/Published online in J-STAGE 28 August 2012)
ABSTRACT. Chronic wasting disease (CWD) has been recognized as a naturally occurring prion disease in North American deer (Odocoileus species), Rocky Mountain elk (Cervus elaphus nelsoni) and moose (Alces alces). The disease was confirmed only in elk in the Republic of Korea in 2001, 2004 and 2005. Epidemiological investigations showed that CWD was introduced via importation of infected elk from Canada between 1994 and 1997. In spite of the increasing geographic distribution and host range of CWD, little is known about the prion strain (s) responsible for distinct outbreaks of the disease. We carried out strain characterization, using transgenic mice overexpressing elk prion protein, including clinical assessment, pathological examination and biochemical analyses, in brain tissues derived following primary through tertiary transmissions. The final incubation period was shortened to approximately 130 dpi due to adaptation. Biochemical profiles remained identical between passages. Lesion profiling in recipient mice brains showed similar patterns of vacuolation scores and intensity. It is clear that there were no biochemical or histopathological differences in Korean CWD cases in 2001 and 2004, suggesting a single strain was responsible for the outbreaks.
Chronic wasting disease (CWD) has been recognized as an important prion disease in North American deer and Rocky mountain elk [13]. This disease was confirmed only in elk in the Republic of Korea in 2001, 2004 and 2005 [7, 10]. Additional CWD cases were observed in red deer, sika deer, and crossbred sika and red deer in 2010 (unpublished data). However, these cases were not included in the present study, which focuses only on elk CWD. Recently, using a model of transgenic mice overexpressing mule deer prion, the possibility of at least two CWD strains existing in North American cervids was raised [1]. More evidence on the two distinct CWD strains that originated from the mule deer was suggested using the ferret model [9] and from Syrian hamster model studies, and the emergence of a new “wasting strain” (WST) would appear to have occurred in white-tailed deer [2]. Epidemiological investigations showed that CWD was introduced to the Korean peninsula via importation of infected elk from Canada in 1994, 1995 and 1997 [7]. It is possible that more than one strain might have been introduced from Canada, although a Canadian retrospective study underway shows no emergence of other phenotypes so far (Dr. Gordon Mitchell, personal comm.).
snip...
KEY WORDS: CWD, Republic of Korea, strain characterization.
doi: 10.1292/jvms.12-0077; J. Vet. Med. Sci. 75(1): 95–98, 2013
see full text;
Friday, May 13, 2011
Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea
A Case of Chronic Wasting Disease in an Elk Imported to Korea from Canada
Hyun-Joo SOHN, Jae-Hoon KIM, Kang-Seuk CHOI, Jin-Ju NAH, Yi-Seok JOO, Young-Hwa JEAN, Soo-Whan AHN, Ok-Kyung KIM, Dae-Yong KIM, Aru BALACHANDRAN Author information Keywords: chronic wasting disease, elk, immunohistochemistry JOURNALS FREE ACCESS 2002 Volume 64 Issue 9 Pages 855-858
Abstract A seven-year-old male elk (Cervus elaphus nelsoni) was euthanized and necropsied after having a 3-week history of body weight loss, emaciation, excessive salivation, teeth grinding, fever, anorexia, and respiratory distress. The elk was imported into Korea from Canada on March 9, 1997. Gross pathologic findings were restricted to a diffuse fibrinous pneumonia. Microscopic lesions included mild neuronal vacuolation and spongiform change in the neuropil of selected brain stem nuclei and generalized astrocytosis. Immunohistochemistry for protease-resistant prion protein (PrPres) was positive in all brain sections but more pronounced in the section of the obex of the medulla. And the PrPres was also detected by western immunoblotting in the brain and spinal cord. All the remaining elk and deer that had been in contact with this elk were destroyed and negative for chronic wasting disease (CWD). To our knowledge, this is the first case of CWD occurring outside of the U.S.A. and Canada.
References (11)
see full text
P-147 Infection and detection of PrPCWD in soil from CWD infected farm in Korea
Hyun Joo Sohn, Kyung Je Park, In Soon Roh, Hyo Jin Kim, Hoo Chang Park, Byounghan Kim
Animal and Plant Quarantine Agency (QIA), Korea
Transmissible spongiform encephalopathy (TSE) is a fatal neurodegenerative disorder, which is so-called as prion diseases due to the causative agents (PrPSc). TSEs are believed to be due to the template-directed accumulation of disease-associated prion protein, generally designated PrPSc. Chronic wasting disease (CWD) is the prion disease that is known spread horizontally. CWD has confirmed last in Republic of Korea in 2010 since first outbreak of CWD in 2001. The environmental reservoirs mediate the transmission of this disease. The significant levels of infectivity have been detected in the saliva, urine, and feces of TSE-infected animals. Using serial protein misfolding cyclic amplification (sPMCA), we developed a detection method for CWD PrPSc in soil from CWD affected farm in 2010. We found to detect PrPSc in soil from CWD infected farm, but not detect PrPSc in soil of wild cervid habitats and normal cervid farm in Korea. We also tried the bioassay on transgenic mice overexpressing elk prion protein (TgElk mice) to confirm infectivity of CWD-infected farm soil and washing solution of it. As the results, there was the presence of infectious prions in them. The attack rates were each 12.5% (1/8, soil) and 100% (6/6, soil washing solution). Our method appears to be a very useful technique for monitoring PrPSc levels in environmental conditions.
P-153
Experimental oral transmission of chronic wasting disease to sika deer (Cervus nippon)
Gordon Mitchell1, Hyun-Joo Sohn2, Yoon-Hee Lee2, Antanas Staskevicius1, Nishandan Yogasingam1, Ines Walther1, In-Soo Cho2, Aru Balachandran1
1National & OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada; 2Animal, Plant and Fisheries Quarantine and Inspection Agency, Ministry for Food, Agriculture, Forestry and Fisheries, Anyang, Republic of Korea
Chronic wasting disease (CWD) persists in North American cervids, and epidemiological evidence indicates CWD was introduced into the Republic of Korea approximately twenty years ago through the importation of an infected elk (Cervus elaphus) from Canada. Additional cases of CWD have since been detected in Korean elk, and recently for the first time in their farmed sika deer (Cervus nippon). Sika deer are also found in regions of North America and Europe, although natural transmission to these populations has not been detected. Understanding the pathogenesis of CWD in this species is therefore essential to developing diagnostic and disease control strategies.
Six sika deer were orally inoculated with a brain homogenate prepared from a farmed Canadian elk with clinical CWD. Four deer developed clinical signs consistent with CWD and were euthanized between 21 and 24 months post-inoculation (mpi). Two deer were removed from the study due to intercurrent disease, at 4 and 11 mpi. At necropsy, an array of tissues and bodily fluids were sampled and preliminary testing of brainstem and lymphoid tissue by ELISA, immunohistochemistry and western blot confirmed CWD transmission. Aggregates of pathological prion protein (PrPCWD) were detected in the retropharyngeal lymph nodes, but not brainstem of the deer sampled at 4 mpi. All other deer, including the deer tested at 11 mpi, displayed marked PrPCWD accumulation in brainstem and lymphoid tissues. Further immunohistochemical analysis of tissues from sika deer with clinical disease revealed widespread PrPCWD deposition in Iymphoreticular tissues, central and peripheral nervous systems, the gastrointestinal tract and neuroendocrine tissues. Western blot molecular profiles in sika deer brainstem samples were similar to the original elk inoculum. Ante-mortem biopsy of recto-anal mucosal associated lymphoid tissue, tested using immunohistochemistry, detected infected sika deer prior to the onset of clinical disease. These findings corroborate studies in other cervids, identifying early and widespread PrPCWD accumulation in tissues following oral inoculation. Efficient transmission of CWD to sika deer dictates a precautionary approach when exposing this species to environments or other cervids potentially infected with CWD.
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Prion 2016 Conference Poster Abstracts
Prion 2016 Oral Abstracts
Prion 2016 Prion Diseases in Animals
Prion 2016 Prion Diseases in Humans
SUNDAY, JULY 14, 2019
Korea Chronic Wasting Disease CWD TSE Prion additional cases were observed in red deer, sika deer, and their crossbred deer in 2010 and 2016, beyond that, anyone's guess
6 Conclusion
The department considers that animal biosecurity risks associated with bulk wheat sourced from the Canadian Prairies for processing can be effectively managed in accordance with the risk management measures outlined in this document. The department considers that the application of those measures will achieve Australia’s ALOP in a least trade-restrictive manner.
THURSDAY, OCTOBER 25, 2018
Norway New additional requirements for imports of hay and straw for animal feed from countries outside the EEA due to CWD TSE Prion
Norway New additional requirements for imports of hay and straw for animal feed from countries outside the EEA due to CWD TSE Prion
$$$$$
***> NORWAY CWD UPDATE December 2018
Report from the Norwegian Scientific Committee for Food and Environment (VKM) 2018: 16
Factors that can contribute to spread of CWD – an update on the situation in Nordfjella, Norway
Opinion of Panel on biological hazards of the Norwegian Scientific Committee for Food and Environment
13.12.2018
ISBN: 978-82-8259-316-8
ISSN: 2535-4019
Norwegian Scientific Committee for Food and Environment (VKM)
Po 222 Skøyen
0213 Oslo
Norway
FRIDAY, DECEMBER 14, 2018
Norway, Nordfjella VKM 2018 16 Factors that can contribute to spread of CWD TSE Prion UPDATE December 14, 2018
THURSDAY, OCTOBER 25, 2018
***> Norway New additional requirements for imports of hay and straw for animal feed from countries outside the EEA due to CWD TSE Prion
new link;
MONDAY, JUNE 12, 2017
Rethinking Major grain organizations opposition to CFIA's control zone approach to Chronic Wasting CWD TSE Prion Mad Deer Type Disease 2017?
FRIDAY, SEPTEMBER 05, 2014
CFIA CWD and Grain Screenings due to potential risk factor of spreading via contamination of grain, oil seeds, etc.
FRIDAY, SEPTEMBER 27, 2013
Uptake of Prions into Plants
WEDNESDAY, OCTOBER 16, 2019
Australia Assessment of bulk wheat from Canada Part B: Animal biosecurity risk advice, CWD TSE Prion concerns are mounting
THURSDAY, SEPTEMBER 26, 2019
Sweden The third case of CWD in moose in Arjeplog is now established
SATURDAY, JUNE 01, 2019
Sweden Documents Another Case of Chronic Wasting Disease CWD TSE Prion Norrbotten
FRIDAY, APRIL 12, 2019
Sweden Wasting Disease (CWD) discovered on moose in Norrbotten County
FRIDAY, MARCH 29, 2019
First Detection of Chronic Wasting Disease in a Wild Red Deer (Cervus elaphus) in Europe
FINLAND MOOSE FOUND DEAD IN FOREST WITH CHRONIC WASTING DISEASE 8.3.2018 12:56
The chronic wasting disease (CWD) has been found in a moose or European elk (Alces alces) for the first time ever in Finland. The disease was diagnosed in Kuhmo in a 15-year old moose that had died naturally. The results of the analyses carried out by Finnish Food Safety Authority Evira have been verified by a EU reference laboratory. Species of the deer family, known as “cervids”, can suffer from the chronic wasting disease, and it is always fatal. The disease is not known to have been contracted by people.
Norway was before this case the only European country where CWD has been diagnosed. The monitoring of the occurrence of the disease was intensified from the beginning of 2018 in Finland and five other EU Member States.
In Finland, the occurrence of the disease has been studied already since 2003. None of the ca. 2 500 samples analysed so far had tested positive for the disease. The monitoring of the disease will now be further intensified in the Kuhmo and Kainuu region. Hunters are going to be provided with more instructions before the start of the next hunting season, if appropriate.
The chronic wasting disease is not known to have been contracted by people. Moose meat is safe to eat and no restrictions are imposed on the sales and exportation of meat of animals of the deer family. As a precautionary measure the export of live animals of the deer family to other countries will be discontinued for now.
CWD is a slowly progressing disease of deer, elk, reindeer, and moose which always leads to death. The chronic wasting disease is a prion disease and related to the BSE (bovine spongiform encephalopathy) and other TSE diseases (transmissible spongiform encephalopathy). The disease is common in North America. The moose found in Kuhmo did not suffer from the North American, highly contagious form of the chronic wasting disease. The disease seems to resemble most the form of cervid TSE diagnosed in Norway, which appears to be found incidentally in individual animals of the deer family.
For more information, please contact:
Leena Räsänen, Director, tel. +358 50 388 6518 (Food Safety)
Terhi Laaksonen, Head of Unit, tel. +358 40 159 5812 (Control of Animal Diseases)
Sirkka-Liisa Korpenfelt, Senior Resarcher, tel. + 358 50 351 0308 (Laboratory Analyses)
Antti Oksanen, Research Professor, tel. +358 44 561 6491 (Wild Animal Diseases)
Kajsa Hakulin, Ministerial Advisor, Ministry of Agriculture and Forestry, tel. +358 295 162361 (National and EU Legislation)
https://www.evira.fi/en/animals/current_issues/2018/moose-found-dead-in-forest-with-chronic-wasting-disease/
SATURDAY, MARCH 10, 2018
FINLAND REPORTS FIRST CASE OF CHRONIC WASTING DISEASE CWD TSE PRION IN A moose or European elk (Alces alces)
WEDNESDAY, MARCH 06, 2019
Norway The Madness Continues in Nordfjella Chronic Wasting Disease CWD TSE Prion
THURSDAY, AUGUST 08, 2019
Raccoons accumulate PrPSc after intracranial inoculation with the agents of chronic wasting disease (CWD) or transmissible mink encephalopathy (TME) but not atypical scrapie
*** 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).***
FRIDAY, JULY 26, 2019
Chronic Wasting Disease in Cervids: Implications for Prion Transmission to Humans and Other Animal Species
atypical and typical BSE and Scrapie Zoonosis
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases).
Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
===============
***thus questioning the origin of human sporadic cases***
===============
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
==============
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online
Taylor & Francis
Prion 2016 Animal Prion Disease Workshop Abstracts
WS-01: Prion diseases in animals and zoonotic potential
Juan Maria Torres a, Olivier Andreoletti b, J uan-Carlos Espinosa a. Vincent Beringue c. Patricia Aguilar a,
Natalia Fernandez-Borges a. and Alba Marin-Moreno a
"Centro de Investigacion en Sanidad Animal ( CISA-INIA ). Valdeolmos, Madrid. Spain; b UMR INRA -ENVT 1225 Interactions Holes Agents Pathogenes. ENVT. Toulouse. France: "UR892. Virologie lmmunologie MolécuIaires, Jouy-en-Josas. France
Dietary exposure to bovine spongiform encephalopathy (BSE) contaminated bovine tissues is considered as the origin of variant Creutzfeldt Jakob (vCJD) disease in human. To date, BSE agent is the only recognized zoonotic prion... Despite the variety of Transmissible Spongiform Encephalopathy (TSE) agents that have been circulating for centuries in farmed ruminants there is no apparent epidemiological link between exposure to ruminant products and the occurrence of other form of TSE in human like sporadic Creutzfeldt Jakob Disease (sCJD). However, the zoonotic potential of the diversity of circulating TSE agents has never been systematically assessed. The major issue in experimental assessment of TSEs zoonotic potential lies in the modeling of the ‘species barrier‘, the biological phenomenon that limits TSE agents’ propagation from a species to another. In the last decade, mice genetically engineered to express normal forms of the human prion protein has proved essential in studying human prions pathogenesis and modeling the capacity of TSEs to cross the human species barrier.
To assess the zoonotic potential of prions circulating in farmed ruminants, we study their transmission ability in transgenic mice expressing human PrPC (HuPrP-Tg). Two lines of mice expressing different forms of the human PrPC (129Met or 129Val) are used to determine the role of the Met129Val dimorphism in susceptibility/resistance to the different agents.
These transmission experiments confirm the ability of BSE prions to propagate in 129M- HuPrP-Tg mice and demonstrate that Met129 homozygotes may be susceptible to BSE in sheep or goat to a greater degree than the BSE agent in cattle and that these agents can convey molecular properties and neuropathological indistinguishable from vCJD. However homozygous 129V mice are resistant to all tested BSE derived prions independently of the originating species suggesting a higher transmission barrier for 129V-PrP variant.
Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
***> why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man.
***> I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough.
***> Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
snip...
R. BRADLEY
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
***> 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. <***
Transmission of scrapie prions to primate after an extended silent incubation period
Emmanuel E. Comoy, Jacqueline Mikol, Sophie Luccantoni-Freire, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Valérie Durand, Capucine Dehen, Olivier Andreoletti, Cristina Casalone, Juergen A. Richt, Justin J. Greenlee, Thierry Baron, Sylvie L. Benestad, Paul Brown & Jean-Philippe Deslys Scientific Reports volume 5, Article number: 11573 (2015) | Download Citation
Abstract
Classical bovine spongiform encephalopathy (c-BSE) is the only animal prion disease reputed to be zoonotic, causing variant Creutzfeldt-Jakob disease (vCJD) in humans and having guided protective measures for animal and human health against animal prion diseases. Recently, partial transmissions to humanized mice showed that the zoonotic potential of scrapie might be similar to c-BSE. We here report the direct transmission of a natural classical scrapie isolate to cynomolgus macaque, a highly relevant model for human prion diseases, after a 10-year silent incubation period, with features similar to those reported for human cases of sporadic CJD. Scrapie is thus actually transmissible to primates with incubation periods compatible with their life expectancy, although fourfold longer than BSE. Long-term experimental transmission studies are necessary to better assess the zoonotic potential of other prion diseases with high prevalence, notably Chronic Wasting Disease of deer and elk and atypical/Nor98 scrapie.
SNIP...
Discussion 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.
The second possibility is a laboratory cross-contamination. Three facts make this possibility equally unlikely. First, handling of specimens in our laboratory is performed with fastidious attention to the avoidance of any such cross-contamination. Second, no laboratory cross-contamination has ever been documented in other primate laboratories, including the NIH, even between infected and uninfected animals housed in the same or adjacent cages with daily intimate contact (P. Brown, personal communication). Third, the cerebral lesion profile is different from all the other prion diseases we have studied in this model19, with a correlation between cerebellar lesions (massive spongiform change of Purkinje cells, intense PrPres staining and reactive gliosis26) and ataxia. The iron deposits present in the globus pallidus are a non specific finding that have been reported previously in neurodegenerative diseases and aging27. Conversely, the thalamic lesion was reminiscent of a metabolic disease due to thiamine deficiency28 but blood thiamine levels were within normal limits (data not shown). The preferential distribution of spongiform change in cortex associated with a limited distribution in the brainstem is reminiscent of the lesion profile in MM2c and VV1 sCJD patients29, but interspecies comparison of lesion profiles should be interpreted with caution. It is of note that the same classical scrapie isolate induced TSE in C57Bl/6 mice with similar incubation periods and lesional profiles as a sample derived from a MM1 sCJD patient30.
We are therefore confident that the illness in this cynomolgus macaque represents a true transmission of a sheep c-scrapie isolate directly to an old-world monkey, which taxonomically resides in the primate subdivision (parvorder of catarrhini) that includes humans. With an homology of its PrP protein with humans of 96.4%31, cynomolgus macaque constitutes a highly relevant model for assessing zoonotic risk of prion diseases. Since our initial aim was to show the absence of transmission of scrapie to macaques in the worst-case scenario, we obtained materials from a flock of naturally-infected sheep, affecting animals with different genotypes32. This c-scrapie isolate exhibited complete transmission in ARQ/ARQ sheep (332 ± 56 days) and Tg338 transgenic mice expressing ovine VRQ/VRQ prion protein (220 ± 5 days) (O. Andreoletti, personal communication). From the standpoint of zoonotic risk, it is important to note that sheep with c-scrapie (including the isolate used in our study) have demonstrable infectivity throughout their lymphoreticular system early in the incubation period of the disease (3 months-old for all the lymphoid organs, and as early as 2 months-old in gut-associated lymph nodes)33. In addition, scrapie infectivity has been identified in blood34, milk35 and skeletal muscle36 from asymptomatic but scrapie infected small ruminants which implies a potential dietary exposure for consumers.
Two earlier studies have reported the occurrence of clinical TSE in cynomolgus macaques after exposures to scrapie isolates. In the first study, the “Compton” scrapie isolate (derived from an English sheep) and serially propagated for 9 passages in goats did not transmit TSE in cynomolgus macaque, rhesus macaque or chimpanzee within 7 years following intracerebral challenge1; conversely, after 8 supplementary passages in conventional mice, this “Compton” isolate induced TSE in a cynomolgus macaque 5 years after intracerebral challenge, but rhesus macaques and chimpanzee remained asymptomatic 8.5 years post-exposure8. However, multiple successive passages that are classically used to select laboratory-adapted prion strains can significantly modify the initial properties of a scrapie isolate, thus questioning the relevance of zoonotic potential for the initial sheep-derived isolate. The same isolate had also induced disease into squirrel monkeys (new-world monkey)9. A second historical observation reported that a cynomolgus macaque developed TSE 6 years post-inoculation with brain homogenate from a scrapie-infected Suffolk ewe (derived from USA), whereas a rhesus macaque and a chimpanzee exposed to the same inoculum remained healthy 9 years post-exposure1. This inoculum also induced TSE in squirrel monkeys after 4 passages in mice. Other scrapie transmission attempts in macaque failed but had more shorter periods of observation in comparison to the current study. Further, it is possible that there are differences in the zoonotic potential of different scrapie strains.
The most striking observation in our study is the extended incubation period of scrapie in the macaque model, which has several implications. Firstly, our observations constitute experimental evidence in favor of the zoonotic potential of c-scrapie, at least for this isolate that has been extensively studied32,33,34,35,36. The cross-species zoonotic ability of this isolate should be confirmed by performing duplicate intracerebral exposures and assessing the transmissibility by the oral route (a successful transmission of prion strains through the intracerebral route may not necessarily indicate the potential for oral transmission37). However, such confirmatory experiments may require more than one decade, which is hardly compatible with current general management and support of scientific projects; thus this study should be rather considered as a case report.
Secondly, transmission of c-BSE to primates occurred within 8 years post exposure for the lowest doses able to transmit the disease (the survival period after inoculation is inversely proportional to the initial amount of infectious inoculum). The occurrence of scrapie 10 years after exposure to a high dose (25 mg) of scrapie-infected sheep brain suggests that the macaque has a higher species barrier for sheep c-scrapie than c-BSE, although it is notable that previous studies based on in vitro conversion of PrP suggested that BSE and scrapie prions would have a similar conversion potential for human PrP38.
Thirdly, prion diseases typically have longer incubation periods after oral exposure than after intracerebral inoculations: since humans can develop Kuru 47 years after oral exposure39, an incubation time of several decades after oral exposure to scrapie would therefore be expected, leading the disease to occur in older adults, i.e. the peak age for cases considered to be sporadic disease, and making a distinction between scrapie-associated and truly sporadic disease extremely difficult to appreciate.
Fourthly, epidemiologic evidence is necessary to confirm the zoonotic potential of an animal disease suggested by experimental studies. A relatively short incubation period and a peculiar epidemiological situation (e.g., all the first vCJD cases occurring in the country with the most important ongoing c-BSE epizootic) led to a high degree of suspicion that c-BSE was the cause of vCJD. Sporadic CJD are considered spontaneous diseases with an almost stable and constant worldwide prevalence (0.5–2 cases per million inhabitants per year), and previous epidemiological studies were unable to draw a link between sCJD and classical scrapie6,7,40,41, even though external causes were hypothesized to explain the occurrence of some sCJD clusters42,43,44. However, extended incubation periods exceeding several decades would impair the predictive values of epidemiological surveillance for prion diseases, already weakened by a limited prevalence of prion diseases and the multiplicity of isolates gathered under the phenotypes of “scrapie” and “sporadic CJD”.
Fifthly, considering this 10 year-long incubation period, together with both laboratory and epidemiological evidence of decade or longer intervals between infection and clinical onset of disease, no premature conclusions should be drawn from negative transmission studies in cynomolgus macaques with less than a decade of observation, as in the aforementioned historical transmission studies of scrapie to primates1,8,9. Our observations and those of others45,46 to date are unable to provide definitive evidence regarding the zoonotic potential of CWD, atypical/Nor98 scrapie or H-type BSE. The extended incubation period of the scrapie-affected macaque in the current study also underscores the limitations of rodent models expressing human PrP for assessing the zoonotic potential of some prion diseases since their lifespan remains limited to approximately two years21,47,48. This point is illustrated by the fact that the recently reported transmission of scrapie to humanized mice was not associated with clinical signs for up to 750 days and occurred in an extreme minority of mice with only a marginal increase in attack rate upon second passage13. The low attack rate in these studies is certainly linked to the limited lifespan of mice compared to the very long periods of observation necessary to demonstrate the development of scrapie. Alternatively, one could estimate that a successful second passage is the result of strain adaptation to the species barrier, thus poorly relevant of the real zoonotic potential of the original scrapie isolate of sheep origin49. The development of scrapie in this primate after an incubation period compatible with its lifespan complements the study conducted in transgenic (humanized) mice; taken together these studies suggest that some isolates of sheep scrapie can promote misfolding of the human prion protein and that scrapie can develop within the lifespan of some primate species.
In addition to previous studies on scrapie transmission to primate1,8,9 and the recently published study on transgenic humanized mice13, our results constitute new evidence for recommending that the potential risk of scrapie for human health should not be dismissed. Indeed, human PrP transgenic mice and primates are the most relevant models for investigating the human transmission barrier. To what extent such models are informative for measuring the zoonotic potential of an animal TSE under field exposure conditions is unknown. During the past decades, many protective measures have been successfully implemented to protect cattle from the spread of c-BSE, and some of these measures have been extended to sheep and goats to protect from scrapie according to the principle of precaution. Since cases of c-BSE have greatly reduced in number, those protective measures are currently being challenged and relaxed in the absence of other known zoonotic animal prion disease. We recommend that risk managers should be aware of the long term potential risk to human health of at least certain scrapie isolates, notably for lymphotropic strains like the classical scrapie strain used in the current study. Relatively high amounts of infectivity in peripheral lymphoid organs in animals infected with these strains could lead to contamination of food products produced for human consumption. Efforts should also be maintained to further assess the zoonotic potential of other animal prion strains in long-term studies, notably lymphotropic strains with high prevalence like CWD, which is spreading across North America, and atypical/Nor98 scrapie (Nor98)50 that was first detected in the past two decades and now represents approximately half of all reported cases of prion diseases in small ruminants worldwide, including territories previously considered as scrapie free... Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
ZOONOSIS OF CWD, BSE, SCRAPIE, TSE PRION
CWD TSE Prion Zoonosis
i was very surprised that no mention of the study out of Canada with oral transmission of CWD to Macaque.
i have spoken with Stefanie Czub and Professor Aguzzi, whom toured her lab afterwards, about these studies. the transmission studies were valid. plus, we know that cwd zoonosis would NOT look like nvCJD, but would look like sporadic CJD of some type. see;
> However, to date, no CWD infections have been reported in people.
key word here is ‘reported’. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can’t, and it’s as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it’s being misdiagnosed as sporadic CJD. …terry
*** LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$ ***
*** 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).***
Chronic Wasting Disease CWD TSE Prion aka mad deer disease zoonosis
We hypothesize that:
(1) The classic CWD prion strain can infect humans at low levels in the brain and peripheral lymphoid tissues;
(2) The cervid-to-human transmission barrier is dependent on the cervid prion strain and influenced by the host (human) prion protein (PrP) primary sequence;
(3) Reliable essays can be established to detect CWD infection in humans; and
(4) CWD transmission to humans has already occurred. We will test these hypotheses in 4 Aims using transgenic (Tg) mouse models and complementary in vitro approaches.
ZOONOTIC CHRONIC WASTING DISEASE CWD TSE PRION UPDATE
Prion 2017 Conference
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1
University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen
This is a progress report of a project which started in 2009. 21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves.
Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice.
At present, a total of 10 animals are sacrificed and read-outs are ongoing. Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10 years. Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation.
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS
PRION 2018 CONFERENCE
Oral transmission of CWD into Cynomolgus macaques: signs of atypical disease, prion conversion and infectivity in macaques and bio-assayed transgenic mice
Hermann M. Schatzl, Samia Hannaoui, Yo-Ching Cheng, Sabine Gilch (Calgary Prion Research Unit, University of Calgary, Calgary, Canada) Michael Beekes (RKI Berlin), Walter Schulz-Schaeffer (University of Homburg/Saar, Germany), Christiane Stahl-Hennig (German Primate Center) & Stefanie Czub (CFIA Lethbridge).
To date, BSE is the only example of interspecies transmission of an animal prion disease into humans. The potential zoonotic transmission of CWD is an alarming issue and was addressed by many groups using a variety of in vitro and in vivo experimental systems. Evidence from these studies indicated a substantial, if not absolute, species barrier, aligning with the absence of epidemiological evidence suggesting transmission into humans. Studies in non-human primates were not conclusive so far, with oral transmission into new-world monkeys and no transmission into old-world monkeys. Our consortium has challenged 18 Cynomolgus macaques with characterized CWD material, focusing on oral transmission with muscle tissue. Some macaques have orally received a total of 5 kg of muscle material over a period of 2 years.
After 5-7 years of incubation time some animals showed clinical symptoms indicative of prion disease, and prion neuropathology and PrPSc deposition were detected in spinal cord and brain of some euthanized animals. PrPSc in immunoblot was weakly detected in some spinal cord materials and various tissues tested positive in RT-QuIC, including lymph node and spleen homogenates. To prove prion infectivity in the macaque tissues, we have intracerebrally inoculated 2 lines of transgenic mice, expressing either elk or human PrP. At least 3 TgElk mice, receiving tissues from 2 different macaques, showed clinical signs of a progressive prion disease and brains were positive in immunoblot and RT-QuIC. Tissues (brain, spinal cord and spleen) from these and pre-clinical mice are currently tested using various read-outs and by second passage in mice. Transgenic mice expressing human PrP were so far negative for clear clinical prion disease (some mice >300 days p.i.). In parallel, the same macaque materials are inoculated into bank voles.
Taken together, there is strong evidence of transmissibility of CWD orally into macaques and from macaque tissues into transgenic mouse models, although with an incomplete attack rate.
The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology.
Our ongoing studies will show whether the transmission of CWD into macaques and passage in transgenic mice represents a form of non-adaptive prion amplification, and whether macaque-adapted prions have the potential to infect mice expressing human PrP.
Our ongoing studies will show whether the transmission of CWD into macaques and passage in transgenic mice represents a form of non-adaptive prion amplification, and whether macaque-adapted prions have the potential to infect mice expressing human PrP.
The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD..
***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD. <***
READING OVER THE PRION 2018 ABSTRACT BOOK, LOOKS LIKE THEY FOUND THAT from this study ;
P190 Human prion disease mortality rates by occurrence of chronic wasting disease in freeranging cervids, United States
Abrams JY (1), Maddox RA (1), Schonberger LB (1), Person MK (1), Appleby BS (2), Belay ED (1) (1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA..
SEEMS THAT THEY FOUND Highly endemic states had a higher rate of prion disease mortality compared to non-CWD
states.
states.
AND ANOTHER STUDY;
P172 Peripheral Neuropathy in Patients with Prion Disease
Wang H(1), Cohen M(1), Appleby BS(1,2) (1) University Hospitals Cleveland Medical Center, Cleveland, Ohio (2) National Prion Disease Pathology Surveillance Center, Cleveland, Ohio..
IN THIS STUDY, THERE WERE autopsy-proven prion cases from the National Prion Disease Pathology Surveillance Center that were diagnosed between September 2016 to March 2017,
AND
included 104 patients. SEEMS THEY FOUND THAT The most common sCJD subtype was MV1-2 (30%), followed by MM1-2 (20%),
AND
THAT The Majority of cases were male (60%), AND half of them had exposure to wild game.
snip…
see more on Prion 2017 Macaque study from Prion 2017 Conference and other updated science on cwd tse prion zoonosis below…terry
PRION 2019 ABSTRACTS
1. Interspecies transmission of the chronic wasting disease agent
Justin Greenlee
Virus and Prion Research Unit, National Animal Disease Center, USDA Agriculture Research Service
ABSTRACT
The presentation will summarize the results of various studies conducted at our research center that assess the transmissibility of the chronic wasting disease (CWD) agent to cattle, pigs, raccoons, goats, and sheep. This will include specifics of the relative attack rates, clinical signs, and microscopic lesions with emphasis on how to differentiate cross-species transmission of the CWD agent from the prion diseases that naturally occur in hosts such as cattle or sheep. Briefly, the relative difficulty of transmitting the CWD agent to sheep and goats will be contrasted with the relative ease of transmitting the scrapie agent to white-tailed deer.
53. Evaluation of the inter-species transmission potential of different CWD isolates
Rodrigo Moralesa, Carlos Kramma,b, Paulina Sotoa, Adam Lyona, Sandra Pritzkowa, Claudio Sotoa
aMitchell Center for Alzheimer’s disease and Related Brain Disorders, Dept. of Neurology, McGovern School of Medicine University of Texas Health Science Center at Houston, TX, USA; bFacultad de Medicina, Universidad de los Andes, Santiago, Chile
ABSTRACT
Chronic Wasting Disease (CWD) has reached epidemic proportions in North America and has been identified in South Korea and Northern Europe. CWD-susceptible cervid species are known to share habitats with humans and other animals entering the human food chain. At present, the potential of CWD to infect humans and other animal species is not completely clear. The exploration of this issue acquires further complexity considering the differences in the prion protein sequence due to species-specific variations and polymorphic changes within species. While several species of cervids are naturally affected by CWD, white-tailed deer (WTD) is perhaps the most relevant due to its extensive use in hunting and as a source of food. Evaluation of inter-species prion infections using animals or mouse models is costly and time consuming. We and others have shown that the Protein Misfolding Cyclic Amplification (PMCA) technology reproduces, in an accelerated and inexpensive manner, the inter-species transmission of prions while preserving the strain features of the input PrPSc. In this work, we tested the potential of different WTD-derived CWD isolates to transmit to humans and other animal species relevant for human consumption using PMCA. For these experiments, CWD isolates homozygous for the most common WTD-PrP polymorphic changes (G96S) were used (96SS variant obtained from a pre-symptomatic prion infected WTD). Briefly, 96GG and 96SS CWD prions were adapted in homologous or heterologous substrate by PMCA through several (15) rounds. End products, as well as intermediates across the process, were tested for their inter-species transmission potentials. A similar process was followed to assess seed-templated misfolding of ovine, porcine, and bovine PrPC. Our results show differences on the inter-species transmission potentials of the four adapted materials generated (PrPC/PrPSc polymorphic combinations), being the homologous combinations of seed/substrate the ones with the greater apparent zoonotic potential. Surprisingly, 96SS prions adapted in homologous substrate were the ones showing the easiest potential to template PrPC misfolding from other animal species. In summary, our results show that a plethora of different CWD isolates, each comprising different potentials for inter-species transmission, may exist in the environment. These experiments may help to clarify an uncertain and potentially worrisome public health issue. Additional research in this area may be useful to advise on the design of regulations intended to stop the spread of CWD and predict unwanted zoonotic events.
56. Understanding chronic wasting disease spread potential for at-risk species
Catherine I. Cullingham, Anh Dao, Debbie McKenzie and David W. Coltman
Department of Biological Sciences, University of Alberta, Edmonton AB, Canada
CONTACT Catherine I. Cullingham cathy.cullingham@ualberta.ca
ABSTRACT
Genetic variation can be linked to susceptibility or resistance to a disease, and this information can help to better understand spread-risk in a population. Wildlife disease incidence is increasing, and this is resulting in negative impacts on the economy, biodiversity, and in some instances, human health. If we can find genetic variation that helps to inform which individuals are susceptible, then we can use this information on at-risk populations to better manage negative consequences. Chronic wasting disease, a fatal, transmissible spongiform encephalopathy of cervids (both wild and captive), continues to spread geographically, which has resulted in an increasing host-range. The disease agent (PrPCWD) is a misfolded conformer of native cellular protein (PrPC). In Canada, the disease is endemic in Alberta and Saskatchewan, infecting primarily mule deer and white-tail deer, with a smaller impact on elk and moose populations. As the extent of the endemic area continues to expand, additional species will be exposed to this disease, including bison, bighorn sheep, mountain goat, and pronghorn antelope. To better understand the potential spread-risk among these species, we reviewed the current literature on species that have been orally exposed to CWD to identify susceptible and resistant species. We then compared the amino acid polymorphisms of PrPC among these species to determine whether any sites were linked to susceptibility or resistance to CWD infection. We sequenced the entire PrP coding region in 578 individuals across at-risk populations to evaluate their potential susceptibility. Three amino acid sites (97, 170, and 174; human numbering) were significantly associated with susceptibility, but these were not fully discriminating. All but one species among the resistant group shared the same haplotype, and the same for the susceptible species. For the at-risk species, bison had the resistant haplotype, while bighorn sheep and mountain goats were closely associated with the resistant type. Pronghorn antelope and a newly identified haplotype in moose differed from the susceptible haplotype, but were still closely associated with it. These data suggest pronghorn antelope will be susceptible to CWD while bison are likely to be resistant. Based on this data, recommendations can be made regarding species to be monitored for possible CWD infection.
KEYWORDS: Chronic wasting disease; Prnp; wildlife disease; population genetics; ungulates
Thursday, May 23, 2019
Prion 2019 Emerging Concepts CWD, BSE, SCRAPIE, CJD, SCIENTIFIC PROGRAM Schedule and Abstracts
see full Prion 2019 Conference Abstracts
THURSDAY, OCTOBER 04, 2018
Cervid to human prion transmission 5R01NS088604-04 Update
snip…full text;
SATURDAY, FEBRUARY 09, 2019
Experts: Yes, chronic wasting disease in deer is a public health issue — for people
FRIDAY, JULY 26, 2019
Chronic Wasting Disease in Cervids: Implications for Prion Transmission to Humans and Other Animal Species
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
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