Chronic Wasting Disease CWD cervids interspecies transmission
Chronic Wasting Disease CWD cervids interspecies transmission
Wednesday, January 5, 2011
ENLARGING SPECTRUM OF PRION-LIKE DISEASES Prusiner Colby et al 2011 Prions
David W. Colby1,* and Stanley B. Prusiner1,2
+ Author Affiliations
1Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California 94143 2Department of Neurology, University of California, San Francisco, San Francisco, California 94143 Correspondence: stanley@ind.ucsf.edu
SNIP...
Greetings,
I believe the statement and quote below is incorrect ;
"CWD has been transmitted to cattle after intracerebral inoculation, although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). This finding raised concerns that CWD prions might be transmitted to cattle grazing in contaminated pastures."
Please see ;
Within 26 months post inoculation, 12 inoculated animals had lost weight, revealed abnormal clinical signs, and were euthanatized. Laboratory tests revealed the presence of a unique pattern of the disease agent in tissues of these animals. These findings demonstrate that when CWD is directly inoculated into the brain of cattle, 86% of inoculated cattle develop clinical signs of the disease.
"although the infection rate was low (4 of 13 animals [Hamir et al. 2001])."
shouldn't this be corrected, 86% is NOT a low rate. ...
kindest regards,
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
MARCH 1, 2011
UPDATED CORRESPONDENCE FROM AUTHORS OF THIS STUDY I.E. COLBY, PRUSINER ET AL, ABOUT MY CONCERNS OF THE DISCREPANCY BETWEEN THEIR FIGURES AND MY FIGURES OF THE STUDIES ON CWD TRANSMISSION TO CATTLE ;
----- Original Message -----
From: David Colby
To: flounder9@verizon.net
Cc: stanley@XXXXXXXX
Sent: Tuesday, March 01, 2011 8:25 AM
Subject: Re: FW: re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 + Author Affiliations
Dear Terry Singeltary,
Thank you for your correspondence regarding the review article Stanley Prusiner and I recently wrote for Cold Spring Harbor Perspectives. Dr. Prusiner asked that I reply to your message due to his busy schedule. We agree that the transmission of CWD prions to beef livestock would be a troubling development and assessing that risk is important. In our article, we cite a peer-reviewed publication reporting confirmed cases of laboratory transmission based on stringent criteria. The less stringent criteria for transmission described in the abstract you refer to lead to the discrepancy between your numbers and ours and thus the interpretation of the transmission rate. We stand by our assessment of the literature--namely that the transmission rate of CWD to bovines appears relatively low, but we recognize that even a low transmission rate could have important implications for public health and we thank you for bringing attention to this matter.
Warm Regards, David Colby
--
David Colby, PhDAssistant ProfessorDepartment of Chemical EngineeringUniversity of Delaware
====================END...TSS==============
SNIP...SEE FULL TEXT ;
UPDATED DATA ON 2ND CWD STRAIN
Wednesday, September 08, 2010
CWD PRION CONGRESS SEPTEMBER 8-11 2010
Research Project: Transmission, Differentiation, and Pathobiology of Transmissible Spongiform Encephalopathies Location: Virus and Prion Diseases of Livestock
Title: TRANSMISSION OF CHRONIC WASTING DISEASE AGENT OF MULE DEER (CWD**MD) TO SUFFOLK SHEEP BY INTRACEREBRAL ROUTE
Authors
Hamir, Amirali Kunkle, Robert Cutlip, Randall - ARS RETIRED Miller, Janice - ARS RETIRED Williams, Elizabeth - UNIVERSITY OF WYOMING Richt, Juergen
Submitted to: European Society of Veterinary Pathology Publication Type: Abstract Publication Acceptance Date: June 5, 2006 Publication Date: August 31, 2006 Citation: Hamir, A., Kunkle, R., Cutlip, R., Miller, J., Williams, E., Richt, J. 2006. Transmission of chronic wasting disease agent of mule deer (CWD**md) to Suffolk sheep by intracerebral route [abstract]. European Society of Veterinary Pathology 24th Annual Meeting. Paper No. P63. p. 171-172.
Technical Abstract: Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) that has been identified in captive and free-ranging cervids in the U.S. since 1967. To determine the transmissibility of CWD to sheep, 8 Suffolk lambs [4 QQ and 4 QR at codon 171 of prion protein (PRNP) gene] were inoculated intracerebrally with a pooled brain suspension from 28 mule deer naturally affected with CWD (CWD**md). Two other lambs (1 QQ and 1 QR at codon 171 of the PRNP gene) were kept as non-inoculated controls. Within 36 months post inoculation (MPI), 2 animals became sick and were euthanized. Only 1 sheep (euthanized at 35 MPI) showed clinical signs that were consistent with those described for scrapie. Microscopic lesions of spongiform encephalopathy (SE) were only seen in the sheep with the clinical signs of TSE and its tissues were positive for the abnormal prion protein (PrP**res) by immunohistochemistry and Western blot. Between 36 and 60 MPI, 3 other sheep were euthanized because of conditions unrelated to TSE. The remaining 3 sheep remained non-clinical at the termination of the study (72 MPI) and were euthanized at that time. One of the 3 animals revealed SE and its tissues were positive for PrP**res. Both sheep positive for PrP**res were homozygous QQ at codon 171. Retrospective examination of the PRNP genotype of the 2 TSE-positive animals revealed that the sheep with clinical prion disease (euthanized at 35 MPI) was heterozygous (AV) and the sheep with the sub-clinical disease (euthanized at 72 MPI) was homozygous (AA) at codon 136 of the PRNP. These findings demonstrate that transmission of the CWD**md agent to sheep via the intracerebral route is possible. Interestingly, the host genotype may play a significant part in successful transmission and incubation period of CWD**md.
Transmission of chronic wasting disease of mule deer to Suffolk sheep following intracerebral inoculation
Amir N. Hamir,1 Robert A. Kunkle, Randall C. Cutlip, Janice M. Miller, Elizabeth S. Williams, Juergen A. Richt
Abstract. To determine the transmissibility of chronic wasting disease (CWD) to sheep, 8 Suffolk lambs of various prion protein genotypes (4 ARQ/ARR, 3 ARQ/ARQ, 1 ARQ/VRQ at codons 136, 154, and 171, respectively) were inoculated intracerebrally with brain suspension from mule deer with CWD (CWDmd). Two other lambs were kept as noninoculated controls. Within 36 months postinoculation (MPI), 2 inoculated animals became sick and were euthanized. Only 1 sheep (euthanized at 35 MPI) showed clinical signs that were consistent with those described for scrapie. Microscopic lesions of spongiform encephalopathy (SE) were only seen in this sheep, and its tissues were determined to be positive for the abnormal prion protein (PrPres) by immunohistochemistry and Western blot. Three other inoculated sheep were euthanized (36 to 60 MPI) because of conditions unrelated to TSE. The 3 remaining inoculated sheep and the 2 control sheep did not have clinical signs of disease at the termination of the study (72 MPI) and were euthanized. Of the 3 remaining inoculated sheep, 1 was found to have SE, and its tissues were positive for PrPres. The sheep with clinical prion disease (euthanized at 35 MPI) was of the heterozygous genotype (ARQ/VRQ), and the sheep with subclinical disease (euthanized at 72 MPH) was of the homozygous ARQ/ARQ genotype. These findings demonstrate that transmission of the CWDmd agent to sheep via the intracerebral route is possible. Interestingly, the host genotype may play a notable part in successful transmission and incubation period of CWDmd.
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Thus far, among domestic animals, CWDmd has been transmitted by the intracerebral route to a goat18 and cattle.5–7 The present findings demonstrate that it is also possible to transmit CWDmd agent to sheep via the intracerebral route. However, the only sheep to develop clinical TSE within 35 MPI was genotypically AV at PRNP codon 136, suggesting that host genotype may play a notable part in successful transmission of the disease in this species. Although in Suffolk sheep the AV variant at codon 136 is very rare,17 selective breeding of Suffolk sheep with this codon has begun in the hope of testing this differential susceptibility hypothesis in a future study of CWDmd transmission to sheep.
Key words: Chronic wasting disease; immunohistochemistry; intracerebral transmission; prion protein; sheep; spongiform encephalopathy.
Research Project: Transmission, Differentiation, and Pathobiology of Transmissible Spongiform Encephalopathies Location: Virus and Prion Diseases of Livestock
Title: EXPERIMENTAL SECOND PASSAGE OF CHRONIC WASTING DISEASE (CWD(MULE DEER)) AGENT TO CATTLE
Authors
Hamir, Amirali Kunkle, Robert Miller, Janice - ARS RETIRED Greenlee, Justin Richt, Juergen
Submitted to: Journal of Comparative Pathology Publication Type: Peer Reviewed Journal Publication Acceptance Date: July 25, 2005 Publication Date: January 1, 2006 Citation: Hamir, A.N., Kunkle, R.A., Miller, J.M., Greenlee, J.J., Richt, J.A. 2006. Experimental second passage of chronic wasting disease (CWD(mule deer)) agent to cattle. Journal of Comparative Pathology. 134(1):63-69.
Interpretive Summary: To compare the findings of experimental first and second passage of chronic wasting disease (CWD) in cattle, 6 calves were inoculated into the brain with CWD-mule deer agent previously (first) passaged in cattle. Two other uninoculated calves served as controls. Beginning 10-12 months post inoculation (PI), all inoculates lost appetite and weight. Five animals subsequently developed clinical signs of central nervous system (CNS) abnormality. By 16.5 months PI, all cattle had been euthanized because of poor prognosis. None of the animals showed microscopic lesions of spongiform encephalopathy (SE) but the CWD agent was detected in their CNS tissues by 2 laboratory techniques (IHC and WB). These findings demonstrate that inoculated cattle amplify CWD agent but also develop clinical CNS signs without manifestation of microscopic lesions of SE. This situation has also been shown to occur following inoculation of cattle with another TSE agent, namely, sheep scrapie. The current study confirms previous work that indicates that the diagnostic tests currently used for confirmation of bovine spongiform encephalopathy (BSE) in the U.S. would detect CWD in cattle, should it occur naturally. Furthermore, it raises the possibility of distinguishing CWD from BSE in cattle due to the absence of microscopic lesions and a unique multifocal distribution of PrPres, as demonstrated by IHC, which in this study, appears to be more sensitive than the WB. Technical Abstract: To compare clinicopathological findings of first and second passage of chronic wasting disease (CWD) in cattle, a group of calves (n=6) were intracerebrally inoculated with CWD-mule deer agent previously (first) passaged in cattle. Two other uninoculated calves served as controls. Beginning 10-12 months post inoculation (PI), all inoculates lost appetite and lost weight. Five animals subsequently developed clinical signs of central nervous system (CNS) abnormality. By 16.5 months PI, all cattle had been euthanized because of poor prognosis. None of the animals showed microscopic lesions of spongiform encephalopathy (SE) but PrPres was detected in their CNS tissues by immunohistochemistry (IHC) and Western blot (WB) techniques. These findings demonstrate that intracerebrally inoculated cattle not only amplify CWD PrPres but also develop clinical CNS signs without manifestation of morphologic lesions of SE. This situation has also been shown to occur following inoculation of cattle with another TSE agent, scrapie. The current study confirms previous work that indicates the diagnostic techniques currently used for confirmation of bovine spongiform encephalopathy (BSE) in the U.S. would detect CWD in cattle, should it occur naturally. Furthermore, it raises the possibility of distinguishing CWD from BSE in cattle due to the absence of neuropathologic lesions and a unique multifocal distribution of PrPres, as demonstrated by IHC, which in this study, appears to be more sensitive than the WB.
Wednesday, September 21, 2011
Evidence for distinct CWD strains in experimental CWD in ferrets
Wednesday, October 12, 2011
White-tailed deer are susceptible to the agent of sheep scrapie by intracerebral inoculation
Wednesday, July 06, 2011
Swine Are Susceptible to Chronic Wasting Disease by Intracerebral Inoculation
see incredible infection rate at one of these game farms Wisconsin shut down and bought out. 86% infection rate...
Monday, January 16, 2012
9 GAME FARMS IN WISCONSIN TEST POSITIVE FOR CWD
Tuesday, December 20, 2011
CHRONIC WASTING DISEASE CWD WISCONSIN Almond Deer (Buckhorn Flats) Farm Update DECEMBER 2011
SNIP...SEE FULL TEXT ;
*** Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.
CWD END OF YEAR REVIEW 2011
EFSA Journal 2011 The European Response to BSE: A Success Story
This is an interesting editorial about the Mad Cow Disease debacle, and it’s ramifications that will continue to play out for decades to come ;
Monday, October 10, 2011
EFSA Journal 2011 The European Response to BSE: A Success Story
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EFSA and the European Centre for Disease Prevention and Control (ECDC) recently delivered a scientific opinion on any possible epidemiological or molecular association between TSEs in animals and humans (EFSA Panel on Biological Hazards (BIOHAZ) and ECDC, 2011). This opinion confirmed Classical BSE prions as the only TSE agents demonstrated to be zoonotic so far but the possibility that a small proportion of human cases so far classified as “sporadic” CJD are of zoonotic origin could not be excluded. Moreover, transmission experiments to non-human primates suggest that some TSE agents in addition to Classical BSE prions in cattle (namely L-type Atypical BSE, Classical BSE in sheep, transmissible mink encephalopathy (TME) and chronic wasting disease (CWD) agents) might have zoonotic potential.
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see follow-up here about North America BSE Mad Cow TSE prion risk factors, and the ever emerging strains of Transmissible Spongiform Encephalopathy in many species here in the USA, including humans ;
Chronic Wasting Disease Susceptibility of Four North American Rodents
Chad J. Johnson1*, Jay R. Schneider2, Christopher J. Johnson2, Natalie A. Mickelsen2, Julia A. Langenberg3, Philip N. Bochsler4, Delwyn P. Keane4, Daniel J. Barr4, and Dennis M. Heisey2 1University of Wisconsin School of Veterinary Medicine, Department of Comparative Biosciences, 1656 Linden Drive, Madison WI 53706, USA 2US Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison WI 53711, USA 3Wisconsin Department of Natural Resources, 101 South Webster Street, Madison WI 53703, USA 4Wisconsin Veterinary Diagnostic Lab, 445 Easterday Lane, Madison WI 53706, USA *Corresponding author email: cjohnson@svm.vetmed.wisc.edu
We intracerebrally challenged four species of native North American rodents that inhabit locations undergoing cervid chronic wasting disease (CWD) epidemics. The species were: deer mice (Peromyscus maniculatus), white-footed mice (P. leucopus), meadow voles (Microtus pennsylvanicus), and red-backed voles (Myodes gapperi). The inocula were prepared from the brains of hunter-harvested white-tailed deer from Wisconsin that tested positive for CWD. Meadow voles proved to be most susceptible, with a median incubation period of 272 days. Immunoblotting and immunohistochemistry confirmed the presence of PrPd in the brains of all challenged meadow voles. Subsequent passages in meadow voles lead to a significant reduction in incubation period. The disease progression in red-backed voles, which are very closely related to the European bank vole (M. glareolus) which have been demonstrated to be sensitive to a number of TSEs, was slower than in meadow voles with a median incubation period of 351 days. We sequenced the meadow vole and red-backed vole Prnp genes and found three amino acid (AA) differences outside of the signal and GPI anchor sequences. Of these differences (T56-, G90S, S170N; read-backed vole:meadow vole), S170N is particularly intriguing due its postulated involvement in "rigid loop" structure and CWD susceptibility. Deer mice did not exhibit disease signs until nearly 1.5 years post-inoculation, but appear to be exhibiting a high degree of disease penetrance. White-footed mice have an even longer incubation period but are also showing high penetrance. Second passage experiments show significant shortening of incubation periods. Meadow voles in particular appear to be interesting lab models for CWD. These rodents scavenge carrion, and are an important food source for many predator species. Furthermore, these rodents enter human and domestic livestock food chains by accidental inclusion in grain and forage. Further investigation of these species as potential hosts, bridge species, and reservoirs of CWD is required.
please see ;
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.
www.landesbioscience.com Prion
see more recent science abstracts from the Prion 2011 on CWD here ;
PAGE 25
Transmission Studies
Mule deer transmissions of CWD were by intracerebral inoculation and compared with natural cases resulted in a more rapidly progressive clinical disease with repeated episodes of synocopy ending in coma. One control animal became affected, it is believed through contamination of inoculam (?saline).
Further CWD transmissions were carried out by Dick Marsh into ferret, mink and squirrel monkey. Transmission occurred in all of these species with the shortest incubation period in the ferret.
Generation of a New Form of Human PrPScin Vitro by Interspecies Transmission from Cervid Prions*
Marcelo A. Barria‡, Glenn C. Telling§, Pierluigi Gambetti¶, James A. Mastrianni‖ and Claudio Soto‡,1
+ Author Affiliations
From the ‡Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Medical School at Houston, Houston, Texas 77030,
the §Departments of Microbiology, Immunology, and Molecular Genetics and Neurology, Sanders Brown Center on Aging, University of Kentucky Medical Center, Lexington, Kentucky 40506,
the ¶Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106, and
the ‖Department of Neurology, The University of Chicago, Chicago, Illinois 60637
1 To whom correspondence should be addressed: University of Texas Medical School at Houston, 6431 Fannin St., Houston, TX 77030. Tel.: 713-500-7086; Fax: 713-500-0667; E-mail: claudio.soto@uth.tmc.edu.
Abstract
Prion diseases are infectious neurodegenerative disorders that affect humans and animals and that result from the conversion of normal prion protein (PrPC) into the misfolded prion protein (PrPSc). Chronic wasting disease (CWD) is a prion disorder of increasing prevalence within the United States that affects a large population of wild and captive deer and elk. Determining the risk of transmission of CWD to humans is of utmost importance, considering that people can be infected by animal prions, resulting in new fatal diseases. To study the possibility that human PrPC can be converted into the misfolded form by CWD PrPSc, we performed experiments using the protein misfolding cyclic amplification technique, which mimics in vitro the process of prion replication. Our results show that cervid PrPSc can induce the conversion of human PrPC but only after the CWD prion strain has been stabilized by successive passages in vitro or in vivo. Interestingly, the newly generated human PrPSc exhibits a distinct biochemical pattern that differs from that of any of the currently known forms of human PrPSc. Our results also have profound implications for understanding the mechanisms of the prion species barrier and indicate that the transmission barrier is a dynamic process that depends on the strain and moreover the degree of adaptation of the strain. If our findings are corroborated by infectivity assays, they will imply that CWD prions have the potential to infect humans and that this ability progressively increases with CWD spreading.
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Interestingly, when the Western blot profile of this newly generated form of human PrPSc (termed CWD-huPrPSc) was compared with known strains of human prions, it was clear that CWD-huPrPSc exhibited a different pattern (Fig. 4A). The electrophoretic migration of this protein after PK-digestion is similar to the type 1 strain of sCJD, but its glycosylation profile is clearly different, showing a highly predominant diglycosylated form (Fig. 4A and B). This result suggests that CWD hu-PrPSc corresponds to a new human prion strain. Interestingly, a detailed previous study from Gambetti’s group comparing the biochemical characteristics of PrPSc from cervids and humans showed that CWD PrPSc is similar to sCJDMM1 in terms of electrophoretic mobility (6). However, the misfolded protein associated with CWD is predominantly di-glycosylated, whereas PrPSc from type 1 sCJD is mostly monoglycosylated (6). Based on the fact that transmission of BSE prions to humans resulted in a new form of PrPSc very similar to the one in cattle (6;27), these authors predicted that if humans were infected by CWD it is likely that PrPSc would be of type 1 and with a predominance of the diglycosylated isoform (6). Our results agree with that prediction and suggest that the newly generated CWD-huPrPSc acquires the biochemical properties of the cervid infectious material (Fig. 4A and B).
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Our results have far-reaching implications for human health, since they indicate that cervid PrPSc can trigger the conversion of human PrPC into PrPSc, suggesting that CWD might be infectious to humans. Interestingly our findings suggest that unstable strains from CWD affected animals might not be a problem for humans, but upon strain stabilization by successive passages in the wild, this disease might become progressively more transmissible to man.
Reference List
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please see full text and many thanks to the Professor Soto and the other Authors of this study AND to The Journal Of Biological Chemistry for the free full text !!!
Amyloid Neurodegeneration Neurological Diseases Prions Protein Conformation Prion Diseases
see full text and more here ;
PLEASE NOTE ;
there are now two documented strains of CWD, and science is showing that indeed CWD could transmit to humans via transmission studies ;
P35
ADAPTATION OF CHRONIC WASTING DISEASE (CWD) INTO HAMSTERS, EVIDENCE OF A WISCONSIN STRAIN OF CWD
Chad Johnson1, Judd Aiken2,3,4 and Debbie McKenzie4,5 1 Department of Comparative Biosciences, University of Wisconsin, Madison WI, USA 53706 2 Department of Agriculture, Food and Nutritional Sciences, 3 Alberta Veterinary Research Institute, 4.Center for Prions and Protein Folding Diseases, 5 Department of Biological Sciences, University of Alberta, Edmonton AB, Canada T6G 2P5
The identification and characterization of prion strains is increasingly important for the diagnosis and biological definition of these infectious pathogens. Although well-established in scrapie and, more recently, in BSE, comparatively little is known about the possibility of prion strains in chronic wasting disease (CWD), a disease affecting free ranging and captive cervids, primarily in North America. We have identified prion protein variants in the white-tailed deer population and demonstrated that Prnp genotype affects the susceptibility/disease progression of white-tailed deer to CWD agent. The existence of cervid prion protein variants raises the likelihood of distinct CWD strains. Small rodent models are a useful means of identifying prion strains. We intracerebrally inoculated hamsters with brain homogenates and phosphotungstate concentrated preparations from CWD positive hunter-harvested (Wisconsin CWD endemic area) and experimentally infected deer of known Prnp genotypes. These transmission studies resulted in clinical presentation in primary passage of concentrated CWD prions. Subclinical infection was established with the other primary passages based on the detection of PrPCWD in the brains of hamsters and the successful disease transmission upon second passage. Second and third passage data, when compared to transmission studies using different CWD inocula (Raymond et al., 2007) indicate that the CWD agent present in the Wisconsin white-tailed deer population is different than the strain(s) present in elk, mule-deer and white-tailed deer from the western United States endemic region.
PPo3-7:
Prion Transmission from Cervids to Humans is Strain-dependent
Qingzhong Kong, Shenghai Huang,*Fusong Chen, Michael Payne, Pierluigi Gambetti and Liuting Qing Department of Pathology; Case western Reserve University; Cleveland, OH USA *Current address: Nursing Informatics; Memorial Sloan-Kettering Cancer Center; New York, NY USA
Key words: CWD, strain, human transmission
Chronic wasting disease (CWD) is a widespread prion disease in cervids (deer and elk) in North America where significant human exposure to CWD is likely and zoonotic transmission of CWD is a concern. Current evidence indicates a strong barrier for transmission of the classical CWD strain to humans with the PrP-129MM genotype. A few recent reports suggest the presence of two or more CWD strains. What remain unknown is whether individuals with the PrP-129VV/MV genotypes are also resistant to the classical CWD strain and whether humans are resistant to all natural or adapted cervid prion strains. Here we report that a human prion strain that had adopted the cervid prion protein (PrP) sequence through passage in cervidized transgenic mice efficiently infected transgenic mice expressing human PrP, indicating that the species barrier from cervid to humans is prion strain-dependent and humans can be vulnerable to novel cervid prion strains. Preliminary results on CWD transmission in transgenic mice expressing human PrP-129V will also be discussed.
Acknowledgement Supported by NINDS NS052319 and NIA AG14359.
PPo2-27:
Generation of a Novel form of Human PrPSc by Inter-species Transmission of Cervid Prions
Marcelo A. Barria,1 Glenn C. Telling,2 Pierluigi Gambetti,3 James A. Mastrianni4 and Claudio Soto1 1Mitchell Center for Alzheimer's disease and related Brain disorders; Dept of Neurology; University of Texas Houston Medical School; Houston, TX USA; 2Dept of Microbiology, Immunology & Molecular Genetics and Neurology; Sanders Brown Center on Aging; University of Kentucky Medical Center; Lexington, KY USA; 3Institute of Pathology; Case western Reserve University; Cleveland, OH USA; 4Dept of Neurology; University of Chicago; Chicago, IL USA
Prion diseases are infectious neurodegenerative disorders affecting humans and animals that result from the conversion of normal prion protein (PrPC) into the misfolded and infectious prion (PrPSc). Chronic wasting disease (CWD) of cervids is a prion disorder of increasing prevalence within the United States that affects a large population of wild and captive deer and elk. CWD is highly contagious and its origin, mechanism of transmission and exact prevalence are currently unclear. The risk of transmission of CWD to humans is unknown. Defining that risk is of utmost importance, considering that people have been infected by animal prions, resulting in new fatal diseases. To study the possibility that human PrPC can be converted into the infectious form by CWD PrPSc we performed experiments using the Protein Misfolding Cyclic Amplification (PMCA) technique, which mimic in vitro the process of prion replication. Our results show that cervid PrPSc can induce the pathological conversion of human PrPC, but only after the CWD prion strain has been stabilized by successive passages in vitro or in vivo. Interestingly, this newly generated human PrPSc exhibits a distinct biochemical pattern that differs from any of the currently known forms of human PrPSc, indicating that it corresponds to a novel human prion strain. Our findings suggest that CWD prions have the capability to infect humans, and that this ability depends on CWD strain adaptation, implying that the risk for human health progressively increases with the spread of CWD among cervids.
PPo2-7:
Biochemical and Biophysical Characterization of Different CWD Isolates
Martin L. Daus and Michael Beekes Robert Koch Institute; Berlin, Germany
Key words: CWD, strains, FT-IR, AFM
Chronic wasting disease (CWD) is one of three naturally occurring forms of prion disease. The other two are Creutzfeldt-Jakob disease in humans and scrapie in sheep. CWD is contagious and affects captive as well as free ranging cervids. As long as there is no definite answer of whether CWD can breach the species barrier to humans precautionary measures especially for the protection of consumers need to be considered. In principle, different strains of CWD may be associated with different risks of transmission to humans. Sophisticated strain differentiation as accomplished for other prion diseases has not yet been established for CWD. However, several different findings indicate that there exists more than one strain of CWD agent in cervids. We have analysed a set of CWD isolates from white-tailed deer and could detect at least two biochemically different forms of disease-associated prion protein PrPTSE. Limited proteolysis with different concentrations of proteinase K and/or after exposure of PrPTSE to different pH-values or concentrations of Guanidinium hydrochloride resulted in distinct isolate-specific digestion patterns. Our CWD isolates were also examined in protein misfolding cyclic amplification studies. This showed different conversion activities for those isolates that had displayed significantly different sensitivities to limited proteolysis by PK in the biochemical experiments described above. We further applied Fourier transform infrared spectroscopy in combination with atomic force microscopy. This confirmed structural differences in the PrPTSE of at least two disinct CWD isolates. The data presented here substantiate and expand previous reports on the existence of different CWD strains.
Saturday, November 12, 2011
Human Prion Disease and Relative Risk Associated with Chronic Wasting Disease
Fri, 22 Sep 2006 09:05:59 –0500
Tuesday, May 31, 2011
Chronic Wasting Disease
DOI: 10.1007/128_2011_159 # Springer-Verlag Berlin Heidelberg 2011
Top Curr Chem (2011) DOI: 10.1007/128_2011_159 # Springer-Verlag Berlin Heidelberg 2011
Chronic Wasting Disease
Sabine Gilch, Nandini Chitoor, Yuzuru Taguchi, Melissa Stuart, Jean E. Jewell, and Hermann M. Schatzl
Abstract
Chronic wasting disease (CWD) is a prion disease of free-ranging and farmed ungulates (deer, elk, and moose) in North America and South Korea. First described by the late E.S. Williams and colleagues in northern Colorado and southern Wyoming in the 1970s, CWD has increased tremendously both in numerical and geographical distribution, reaching prevalence rates as high as 50% in freeranging and >90% in captive deer herds in certain areas of USA and Canada. CWD is certainly the most contagious prion infection, with significant horizontal transmission of infectious prions by, e.g., urine, feces, and saliva. Dissemination and persistence of infectivity in the environment combined with the appearance in wildliving and migrating animals make CWD presently uncontrollable, and pose extreme challenges to wild-life disease management. Whereas CWD is extremely transmissible among cervids, its trans-species transmission seems to be restricted, although the possible involvement of rodent and carnivore species in environmental transmission has not been fully evaluated. Whether or not CWD has zoonotic potential as had Bovine spongiform encephalopathy (BSE) has yet to be answered. Of note, variant Creutzfeldt–Jakob disease (vCJD) was only detected because clinical presentation and age of patients were significantly different from classical CJD. Along with further understanding of the molecular biology and pathology of CWD, its transmissibility and species restrictions and development of methods for preclinical diagnosis and intervention will be crucial for effective containment of this highly contagious prion disease.
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8 Zoonotic Potential Deer hunting is a popular sport in the USA; venison is usually consumed by hunters and their families, and this raises reasonable concerns about the transmissibility of CWD to humans, as exemplified by the zoonotic transmission of BSE. Epidemiological studies have not revealed an increased incidence of CJD in CWD endemic areas. Suspicious case reports about persons having consumed venison and succumbed to neurological disorders turned out to be classical or familial CJD and a causal link to the consumption of contaminated meat could not be proven [109]. In vitro conversion assays were performed to assess the convertibility of human PrPc into PK resistant PrP using CWD derived from elk, mule deer, and white-tailed deer as a template. Only a very low conversion rate could be demonstrated, indicative of a considerable species barrier [110]. In a very recent study employing protein misfolding cyclic amplification (PMCA), a highly sensitive method for in vitro amplification conversion of human PrPc was successful, albeit with the restriction that CWD prions had to be adapted by PMCA or in vivo passage through cervidized tg mice. Passaged CWD template gave rise to a new form of human PrPSc, and its infectivity is currently under investigation. Of note, when field isolates of CWD Chronic Wasting Disease brains were used as a template, no conversion of human PrPc was achieved, which again questions the relevance of the in vitro data [111]. Studies using humanized tg mouse inoculated with CWD furthermore argue against transmissibility to humans since mice did not develop prion disease [112–114]. The best possible animal models to study transmission of animal prion diseases to humans probably are non-human primates. For instance, inoculation of BSE prions into Cynomolgus macaques provided the first hints that BSE might be transmissible to humans [115]. However, oral or i.c. challenge with CWD of macaques did not cause disease [116]. On the other hand, squirrel monkeys (Saimiri sciureus) were susceptible to i.c. inoculation with CWD prions [116, 117], and after oral exposure PrPSc was detectable in brain, spleen, and lymph nodes of 2/15 squirrel monkeys [116]. This shows that CWD can be transmitted to certain non-human primates, although results in Cynomolgus macaques might be of higher relevance since they are evolutionary closer relatives of humans than squirrel monkeys. Overall, there is no compelling evidence that CWD can be transmitted to humans with high efficiency.
snip...end
Monday, June 27, 2011
Zoonotic Potential of CWD: Experimental Transmissions to Non-Human Primates
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
PLUS, THE CDC DID NOT PUT THIS WARNING OUT FOR THE WELL BEING OF THE DEER AND ELK ;
Thursday, May 26, 2011
Travel History, Hunting, and Venison Consumption Related to Prion Disease Exposure, 2006-2007 FoodNet Population Survey
Journal of the American Dietetic Association Volume 111, Issue 6 , Pages 858-863, June 2011.
NOR IS THE FDA recalling this CWD positive elk meat for the well being of the dead elk ;
Wednesday, March 18, 2009
Noah's Ark Holding, LLC, Dawson, MN RECALL Elk products contain meat derived from an elk confirmed to have CWD NV, CA, TX, CO, NY, UT, FL, OK RECALLS AND FIELD CORRECTIONS: FOODS CLASS II
Thursday, May 26, 2011
Travel History, Hunting, and Venison Consumption Related to Prion Disease Exposure, 2006-2007 FoodNet Population Survey Journal of the American Dietetic Association Volume 111, Issue 6 , Pages 858-863, June 2011.
Travel History, Hunting, and Venison Consumption Related to Prion Disease Exposure, 2006-2007 FoodNet Population Survey
Joseph Y. Abrams, MPH, Ryan A. Maddox, MPH , Alexis R. Harvey, MPH , Lawrence B. Schonberger, MD , Ermias D. Belay, MD
Accepted 15 November 2010. Abstract Full Text PDF References .
Abstract
The transmission of bovine spongiform encephalopathy (BSE) to human beings and the spread of chronic wasting disease (CWD) among cervids have prompted concerns about zoonotic transmission of prion diseases. Travel to the United Kingdom and other European countries, hunting for deer or elk, and venison consumption could result in the exposure of US residents to the agents that cause BSE and CWD. The Foodborne Diseases Active Surveillance Network 2006-2007 population survey was used to assess the prevalence of these behaviors among residents of 10 catchment areas across the United States. Of 17,372 survey respondents, 19.4% reported travel to the United Kingdom since 1980, and 29.5% reported travel to any of the nine European countries considered to be BSE-endemic since 1980. The proportion of respondents who had ever hunted deer or elk was 18.5%, and 1.2% had hunted deer or elk in a CWD–endemic area. More than two thirds (67.4%) reported having ever eaten deer or elk meat. Respondents who traveled spent more time in the United Kingdom (median 14 days) than in any other BSE-endemic country. Of the 11,635 respondents who had consumed venison, 59.8% ate venison at most one to two times during their year of highest consumption, and 88.6% had obtained all of their meat from the wild. The survey results were useful in determining the prevalence and frequency of behaviors that could be important factors for foodborne prion transmission.
"These findings indicate that a high percentage of the United States population engages in hunting and/or venison consumption. If CWD continues to spread to more areas across the country, a substantial number of people could potentially be exposed to the infectious agent."
Potential Venison Exposure Among FoodNet Population Survey Respondents, 2006-2007
Ryan A. Maddox1*, Joseph Y. Abrams1, Robert C. Holman1, Lawrence B. Schonberger1, Ermias D. Belay1 Division of Viral and Rickettsial Diseases, National Center for Zoonotic, Vector-Borne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, GA *Corresponding author e-mail: rmaddox@cdc.gov
The foodborne transmission of bovine spongiform encephalopathy to humans, resulting in variant Creutzfeldt-Jakob disease, indicates that humans can be susceptible to animal prion diseases. However, it is not known whether foodborne exposure to the agent causing chronic wasting disease (CWD) in cervids can cause human disease. The United States Foodborne Diseases Active Surveillance Network (FoodNet) conducts surveillance for foodborne diseases through an extensive survey administered to respondents in selected states. To describe the frequency of deer and elk hunting and venison consumption, five questions were included in the 2006-2007 FoodNet survey. This survey included 17,372 respondents in ten states: California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New Mexico, New York, Oregon, and Tennessee. Of these respondents, 3,220 (18.5%) reported ever hunting deer or elk, with 217 (1.3%) reporting hunting in a CWD-endemic area (northeastern Colorado, southeastern Wyoming, and southwestern Nebraska). Of the 217 CWD-endemic area hunters, 74 (34.1%) were residents of Colorado. Respondents reporting hunting were significantly more likely to be male than female (prevalence ratio: 3.3, 95% confidence interval: 3.1-3.6) and, in general, older respondents were significantly more likely to report hunting than younger respondents. Venison consumption was reported by more than half (67.4%) of the study population, and most venison consumers (94.1%) reported that at least half of their venison came from the wild. However, more than half (59.1%) of the consumers reported eating venison only one to five times in their life or only once or twice a year. These findings indicate that a high percentage of the United States population engages in hunting and/or venison consumption. If CWD continues to spread to more areas across the country, a substantial number of people could potentially be exposed to the infectious agent.
now, let’s see what the authors said about this casual link, personal communications years ago. see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ????
“Our conclusion stating that we found no strong evidence of CWD transmission to humans”
From: TSS (216-119-163-189.ipset45.wt.net)
Subject: CWD aka MAD DEER/ELK TO HUMANS ???
Date: September 30, 2002 at 7:06 am PST
From: "Belay, Ermias"
To:
Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"
Sent: Monday, September 30, 2002 9:22 AM
Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Dear Sir/Madam,
In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD.
That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091). Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.
Ermias Belay, M.D. Centers for Disease Control and Prevention
-----Original Message-----
From:
Sent: Sunday, September 29, 2002 10:15 AM
To: rr26k@nih.gov; rrace@niaid.nih.gov; ebb8@CDC.GOV
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM ......snip........end..............TSS
Thursday, April 03, 2008
A prion disease of cervids: Chronic wasting disease
2008 1: Vet Res. 2008 Apr 3;39(4):41
A prion disease of cervids: Chronic wasting disease
Sigurdson CJ.
snip...
*** twenty-seven CJD patients who regularly consumed venison were reported to the Surveillance Center***,
snip...
full text ;
Monday, November 14, 2011
WYOMING Creutzfeldt Jakob Disease, CWD, TSE, PRION REPORTING 2011
Wednesday, November 16, 2011
Wisconsin Creutzfeldt Jakob Disease, CWD, TSE, PRION REPORTING 2011
Sunday, November 13, 2011
COLORADO CWD CJD TSE PRION REPORTING 2011
Monday, May 23, 2011 CDC
Assesses Potential Human Exposure to Prion Diseases Travel Warning
Public release date: 23-May-2011
Contact: Francesca Costanzo adajmedia@elsevier.com 215-239-3249 Elsevier Health Sciences
CDC assesses potential human exposure to prion diseases Study results reported in the Journal of the American Dietetic Association Philadelphia, PA, May 23, 2011 – Researchers from the Centers for Disease Control and Prevention (CDC) have examined the potential for human exposure to prion diseases, looking at hunting, venison consumption, and travel to areas in which prion diseases have been reported in animals. Three prion diseases in particular – bovine spongiform encephalopathy (BSE or "Mad Cow Disease"), variant Creutzfeldt-Jakob disease (vCJD), and chronic wasting disease (CWD) – were specified in the investigation. The results of this investigation are published in the June issue of the Journal of the American Dietetic Association.
"While prion diseases are rare, they are generally fatal for anyone who becomes infected. More than anything else, the results of this study support the need for continued surveillance of prion diseases," commented lead investigator Joseph Y. Abrams, MPH, National Center for Emerging and Zoonotic Infectious Diseases, CDC, Atlanta."But it's also important that people know the facts about these diseases, especially since this study shows that a good number of people have participated in activities that may expose them to infection-causing agents."
Although rare, human prion diseases such as CJD may be related to BSE. Prion (proteinaceous infectious particles) diseases are a group of rare brain diseases that affect humans and animals. When a person gets a prion disease, brain function is impaired. This causes memory and personality changes, dementia, and problems with movement. All of these worsen over time. These diseases are invariably fatal. Since these diseases may take years to manifest, knowing the extent of human exposure to possible prion diseases could become important in the event of an outbreak.
CDC investigators evaluated the results of the 2006-2007 population survey conducted by the Foodborne Diseases Active Surveillance Network (FoodNet). This survey collects information on food consumption practices, health outcomes, and demographic characteristics of residents of the participating Emerging Infections Program sites. The survey was conducted in Connecticut, Georgia, Maryland, Minnesota, New Mexico, Oregon, and Tennessee, as well as five counties in the San Francisco Bay area, seven counties in the Greater Denver area, and 34 counties in western and northeastern New York.
Survey participants were asked about behaviors that could be associated with exposure to the agents causing BSE and CWD, including travel to the nine countries considered to be BSE-endemic (United Kingdom, Republic of Ireland, France, Portugal, Switzerland, Italy, the Netherlands, Germany, Spain) and the cumulative length of stay in each of those countries. Respondents were asked if they ever had hunted for deer or elk, and if that hunting had taken place in areas considered to be CWD-endemic (northeastern Colorado, southeastern Wyoming or southwestern Nebraska). They were also asked if they had ever consumed venison, the frequency of consumption, and whether the meat came from the wild.
The proportion of survey respondents who reported travel to at least one of the nine BSE endemic countries since 1980 was 29.5%. Travel to the United Kingdom was reported by 19.4% of respondents, higher than to any other BSE-endemic country. Among those who traveled, the median duration of travel to the United Kingdom (14 days) was longer than that of any other BSE-endemic country. Travelers to the UK were more likely to have spent at least 30 days in the country (24.9%) compared to travelers to any other BSE endemic country. The prevalence and extent of travel to the UK indicate that health concerns in the UK may also become issues for US residents.
The proportion of survey respondents reporting having hunted for deer or elk was 18.5% and 1.2% reported having hunted for deer or elk in CWD-endemic areas. Venison consumption was reported by 67.4% of FoodNet respondents, and 88.6% of those reporting venison consumption had obtained all of their meat from the wild. These findings reinforce the importance of CWD surveillance and control programs for wild deer and elk to reduce human exposure to the CWD agent. Hunters in CWD-endemic areas are advised to take simple precautions such as: avoiding consuming meat from sickly deer or elk, avoiding consuming brain or spinal cord tissues, minimizing the handling of brain and spinal cord tissues, and wearing gloves when field-dressing carcasses.
According to Abrams, "The 2006-2007 FoodNet population survey provides useful information should foodborne prion infection become an increasing public health concern in the future. The data presented describe the prevalence of important behaviors and their associations with demographic characteristics. Surveillance of BSE, CWD, and human prion diseases are critical aspects of addressing the burden of these diseases in animal populations and how that may relate to human health."
###
The article is "Travel history, hunting, and venison consumption related to prion disease exposure, 2006-2007 FoodNet population survey" by Joseph Y. Abrams, MPH; Ryan A. Maddox, MPH; Alexis R Harvey, MPH; Lawrence B. Schonberger, MD; and Ermias D. Belay, MD. It appears in the Journal of the American Dietetic Association, Volume 111, Issue 6 (June 2011) published by Elsevier.
In an accompanying podcast CDC's Joseph Y. Abrams discusses travel, hunting, and eating venison in relation to prion diseases. It is available at http://adajournal.org/content/podcast.
Thursday, December 29, 2011
Aerosols An underestimated vehicle for transmission of prion diseases?
please see more on Aerosols and TSE prion disease here ;
Sunday, July 27, 2008
DOCKET-- 03D-0186 -- FDA Issues Draft Guidance on Use of Material From Deer and Elk in Animal Feed; Availability
-------- Original Message --------
Subject: 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
From: "Terry S. Singeltary Sr."
To: fdadockets@oc.fda.gov
Greetings FDA,
i would kindly like to comment on;
Docket 03D-0186
FDA Issues Draft Guidance on Use of Material From Deer and Elk in Animal Feed; Availability
Several factors on this apparent voluntary proposal disturbs me greatly, please allow me to point them out;
1. MY first point is the failure of the partial ruminant-to-ruminant feed ban of 8/4/97. this partial and voluntary feed ban of some ruminant materials being fed back to cattle is terribly flawed. without the _total_ and _mandatory_ ban of all ruminant materials being fed back to ruminants including cattle, sheep, goat, deer, elk and mink, chickens, fish (all farmed animals for human/animal consumption), this half ass measure will fail terribly, as in the past decades...
2. WHAT about sub-clinical TSE in deer and elk? with the recent findings of deer fawns being infected with CWD, how many could possibly be sub-clinically infected. until we have a rapid TSE test to assure us that all deer/elk are free of disease (clinical and sub-clinical), we must ban not only documented CWD infected deer/elk, but healthy ones as well. it this is not done, they system will fail...
3. WE must ban not only CNS (SRMs specified risk materials), but ALL tissues. recent new and old findings support infectivity in the rump or ass muscle. wether it be low or high, accumulation will play a crucial role in TSEs.
4. THERE are and have been for some time many TSEs in the USA. TME in mink, Scrapie in Sheep and Goats, and unidentified TSE in USA cattle. all this has been proven, but the TSE in USA cattle has been totally ignored for decades. i will document this data below in my references.
5. UNTIL we ban all ruminant by-products from being fed back to ALL ruminants, until we rapid TSE test (not only deer/elk) but cattle in sufficient numbers to find (1 million rapid TSE test in USA cattle annually for 5 years), any partial measures such as the ones proposed while ignoring sub-clinical TSEs and not rapid TSE testing cattle, not closing down feed mills that continue to violate the FDA's BSE feed regulation (21 CFR 589.2000) and not making freely available those violations, will only continue to spread these TSE mad cow agents in the USA. I am curious what we will call a phenotype in a species that is mixed with who knows how many strains of scrapie, who knows what strain or how many strains of TSE in USA cattle, and the CWD in deer and elk (no telling how many strains there), but all of this has been rendered for animal feeds in the USA for decades. it will get interesting once someone starts looking in all species, including humans here in the USA, but this has yet to happen...
6. IT is paramount that CJD be made reportable in every state (especially ''sporadic'' cjd), and that a CJD Questionnaire must be issued to every family of a victim of TSE. only checking death certificates will not be sufficient. this has been proven as well (see below HISTORY OF CJD -- CJD QUESTIONNAIRE)
7. WE must learn from our past mistakes, not continue to make the same mistakes...
snip...
Oral transmission and early lymphoid tropism of chronic wasting disease PrPres in mule deer fawns (Odocoileus hemionus ) Christina J. Sigurdson1, Elizabeth S. Williams2, Michael W. Miller3, Terry R. Spraker1,4, Katherine I. O'Rourke5 and Edward A. Hoover1
Department of Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523- 1671, USA1 Department of Veterinary Sciences, University of Wyoming, 1174 Snowy Range Road, University of Wyoming, Laramie, WY 82070, USA 2 Colorado Division of Wildlife, Wildlife Research Center, 317 West Prospect Road, Fort Collins, CO 80526-2097, USA3 Colorado State University Veterinary Diagnostic Laboratory, 300 West Drake Road, Fort Collins, CO 80523-1671, USA4 Animal Disease Research Unit, Agricultural Research Service, US Department of Agriculture, 337 Bustad Hall, Washington State University, Pullman, WA 99164-7030, USA5
Author for correspondence: Edward Hoover.Fax +1 970 491 0523. e-mail ehoover@lamar.colostate.edu
Mule deer fawns (Odocoileus hemionus) were inoculated orally with a brain homogenate prepared from mule deer with naturally occurring chronic wasting disease (CWD), a prion-induced transmissible spongiform encephalopathy. Fawns were necropsied and examined for PrP res, the abnormal prion protein isoform, at 10, 42, 53, 77, 78 and 80 days post-inoculation (p.i.) using an immunohistochemistry assay modified to enhance sensitivity. PrPres was detected in alimentary-tract-associated lymphoid tissues (one or more of the following: retropharyngeal lymph node, tonsil, Peyer's patch and ileocaecal lymph node) as early as 42 days p.i. and in all fawns examined thereafter (53 to 80 days p.i.). No PrPres staining was detected in lymphoid tissue of three control fawns receiving a control brain inoculum, nor was PrPres detectable in neural tissue of any fawn. PrPres-specific staining was markedly enhanced by sequential tissue treatment with formic acid, proteinase K and hydrated autoclaving prior to immunohistochemical staining with monoclonal antibody F89/160.1.5. These results indicate that CWD PrP res can be detected in lymphoid tissues draining the alimentary tract within a few weeks after oral exposure to infectious prions and may reflect the initial pathway of CWD infection in deer. The rapid infection of deer fawns following exposure by the most plausible natural route is consistent with the efficient horizontal transmission of CWD in nature and enables accelerated studies of transmission and pathogenesis in the native species.
snip...
These results indicate that mule deer fawns develop detectable PrP res after oral exposure to an inoculum containing CWD prions. In the earliest post-exposure period, CWD PrPres was traced to the lymphoid tissues draining the oral and intestinal mucosa (i.e. the retropharyngeal lymph nodes, tonsil, ileal Peyer's patches and ileocaecal lymph nodes), which probably received the highest initial exposure to the inoculum. Hadlow et al. (1982) demonstrated scrapie agent in the tonsil, retropharyngeal and mesenteric lymph nodes, ileum and spleen in a 10-month-old naturally infected lamb by mouse bioassay. Eight of nine sheep had infectivity in the retropharyngeal lymph node. He concluded that the tissue distribution suggested primary infection via the gastrointestinal tract. The tissue distribution of PrPres in the early stages of infection in the fawns is strikingly similar to that seen in naturally infected sheep with scrapie. These findings support oral exposure as a natural route of CWD infection in deer and support oral inoculation as a reasonable exposure route for experimental studies of CWD.
snip...
snip...see full text ;
-------- Original Message --------
Subject: 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
From: "Terry S. Singeltary Sr."
To: fdadockets@oc.fda.gov
Greetings FDA,
i would kindly like to comment on;
Docket 03D-0186
FDA Issues Draft Guidance on Use of Material From Deer and Elk in Animal Feed; Availability
Article
Experimental oral transmission of chronic wasting disease to red deer
(Cervus elaphus elaphus): Early detection and late stage distribution
of protease-resistant prion protein
Aru Balachandran, Noel P. Harrington, James Algire, Andrei Soutyrine, Terry R. Spraker,
Martin Jeffrey, Lorenzo González, Katherine I. O'Rourke
Abstract - Chronic wasting disease (CWD), an important emerging prion disease of cervids, is readily transmitted by intracerebral or oral inoculation from deer-to-deer and elk-to-elk, suggesting the latter is a natural route of exposure. Studies of host range susceptibility to oral infection, particularly of those species found in habitats where CWD currently exists are imperative. This report describes the experimental transmission of CWD to red deer following oral inoculation with infectious CWD material of elk origin. At 18 to 20 months post-inoculation, mild to moderate neurological signs and weight loss were observed and animals were euthanized and tested using 3 conventional immunological assays. The data indicate that red deer are susceptible to oral challenge and that tissues currently used for CWD diagnosis show strong abnormal prion (PrPCWD) accumulation. Widespread peripheral PrPCWD deposition involves lymphoreticular tissues, endocrine tissues, and cardiac muscle and suggests a potential source of prion infectivity, a means of horizontal transmission and carrier state.
SNIP...
There is a strong correlation between the presence of PrPTSE and infectivity in prion diseases. Although the epidemiologic evidence strongly suggests that CWD is not transmissible to humans, this study and others suggest caution in this regard. The finding of PrPCWD in various organs, albeit in clinical CWD, suggests that humans who consume or handle meat from CWD-infected red deer may be at risk of exposure to CWD prions. This study found that red deer tissues other than nervous and lymphoid tissue can support CWD prion replication and accumulation. As a result, the consumption or handling of meat from CWD-infected red deer will put humans at risk of exposure to CWD prions. In spite of a well-documented species barrier, a cautious approach would involve preventing such tissues from entering the animal and human food chains. Future studies will require sensitive and quantitative techniques such as bioassays in transgenic mice that assess tissue infectivity and quantitative immunoassays adapted to PrPCWD detection in peripheral tissues.
SNIP...
The exact mode of transmission of CWD in nature remains unclear but is believed to involve direct animal-to-animal contact or environmental contamination. As TSE agents are extremely resistant in the environment (39), oral exposure is the most plausible pathway by which the CWD prion may be introduced to deer in nature and represents a significant obstacle to eradication of CWD from either farmed or free-ranging cervid populations. The distribution of PrPCWD in gut-associated lymphoid tissues, salivary glands, and nasal mucosa in the red deer of this study suggests potential routes of PrPCWD shedding into the environment via fluids such as saliva or feces. However, this study did not identify the point at which an animal may become infectious during the course of infection. An improved understanding of the mechanisms of shedding and transmission will be important in the future management of CWD.
SNIP...
In summary, this study demonstrates the potential for oral transmission of CWD to red deer and describes the pattern of PrPCWD accumulation for this species. The current surveillance testing regime for cervids would be expected to identify CWD-infected red deer should it occur in North America. These results confirm the usefulness of rapid tests such as ELISA but with generally slightly lower sensitivity when compared with IHC when testing tissues with patchy or sporadic PrPCWD deposition. The finding of PrPCWD in several extraneural tissues including cardiac muscle and the endocrine system suggests that further investigation and monitoring of the potential transmissibility to other species including humans is warranted.
SNIP...
(Traduit par Isabelle Vallières)
Can Vet J 2010;51:169-178
Ottawa Laboratory - Fallowfield, Canadian Food Inspection Agency, Ottawa, Ontario (Balachandran, Harrington, Algire,
Soutyrine); Veterinary Diagnostic Laboratory, Colorado State University, Fort Collins, Colorado, USA (Spraker); Veterinary
Laboratory Agency, Department for the Environment, Food & Rural Affairs, Lasswade, Midlothian, Scotland, United Kingdom
(Jeffrey, González); Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture, Pullman,
Washington, USA (O'Rourke).
Address all correspondence to Dr. Aru Balachandran; e-mail: BalachandranA@inspection.gc.ca
Saturday, November 6, 2010
TAFS1 Position Paper on Position Paper on Relaxation of the Feed Ban in the EU Berne, 2010 TAFS
INTERNATIONAL FORUM FOR TRANSMISSIBLE ANIMAL DISEASES AND FOOD SAFETY a non-profit Swiss Foundation
Archive Number 20101206.4364 Published Date 06-DEC-2010 Subject PRO/AH/EDR>
Prion disease update 2010 (11)
PRION DISEASE UPDATE 2010 (11)
Wednesday, January 18, 2012
BSE IN GOATS CAN BE MISTAKEN FOR SCRAPIE
February 1, 2012
Friday, January 6, 2012
OIE 2012 Training Manual on Wildlife Diseases and Surveillance and TSE Prion disease
Tuesday, January 17, 2012
Annual report of the Scientific Network on BSE-TSE EFSA-Q-2011-01110 Issued: 20 December 2011
2011 Monday, September 26, 2011
L-BSE BASE prion and atypical sporadic CJD
TSS
Labels: Chronic Wasting Disease CWD cervids interspecies transmission
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