Sunday, December 14, 2014

North Carolina wildlife board looks into criticism of agency's officers over protection of deer from CWD

Sent: Saturday, December 13, 2014 5:03 PM
Subject: re-NC wildlife board looks into criticism of agency's officers
 

re-NC wildlife board looks into criticism of agency's officers
 
Wildlife officers have been accused of overreacting to the threat of a disease that has never been detected in North Carolina by clamping down on farms where deer are raised. In recent years, the agency has resisted efforts to expand the industry and has killed thousands of deer to test them for chronic waste disease. It cannot be tested in live animals, and it is incurable, fatal and potentially spread by commercial operations. The deer are raised to stock game preserves, for their antlers and other products. snip...end
 
 
Happy Holidays, Merry Christmas. for your information...kind regards, terry
 
***Given that scrapie prions are widespread on the surfaces of affected farms (Maddison and others 2010a), irrespective of the source of the infectious prions in the pens, this study clearly highlights the difficulties that are faced with the effective removal of environmentally associated scrapie infectivity.
 
***This is likely to be paralleled in CWD which shows strong similarities to scrapie in terms of both the dissemination of prions into the environment and the facile mode of disease transmission. These data further contribute to the understanding that prion diseases can be highly transmissible between susceptible individuals not just by direct contact but through highly stable environmental reservoirs that are refractory to decontamination.
 
***The presence of these environmentally associated prions in farm buildings make the control of these diseases a considerable challenge, especially in animal species such as goats where there is lack of genetic resistance to scrapie and, therefore, no scope to re-stock farms with animals that are resistant to scrapie.
 
***These data suggest that recommended current guidelines for the decontamination of farm buildings following outbreaks of scrapie do little to reduce the titre of infectious scrapie material and that environmental recontamination could also be an issue associated with these premises.
 
Scrapie Sheep Goats Transmissible spongiform encephalopathies (TSE) Accepted October 12, 2014. Published Online First 31 October 2014
 
 
Monday, November 3, 2014
 
Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination
 
 
PPo3-22:
 
Detection of Environmentally Associated PrPSc on a Farm with Endemic Scrapie
 
Ben C. Maddison,1 Claire A. Baker,1 Helen C. Rees,1 Linda A. Terry,2 Leigh Thorne,2 Susan J. Belworthy2 and Kevin C. Gough3 1ADAS-UK LTD; Department of Biology; University of Leicester; Leicester, UK; 2Veterinary Laboratories Agency; Surry, KT UK; 3Department of Veterinary Medicine and Science; University of Nottingham; Sutton Bonington, Loughborough UK
 
Key words: scrapie, evironmental persistence, sPMCA
 
Ovine scrapie shows considerable horizontal transmission, yet the routes of transmission and specifically the role of fomites in transmission remain poorly defined. Here we present biochemical data demonstrating that on a scrapie-affected sheep farm, scrapie prion contamination is widespread. It was anticipated at the outset that if prions contaminate the environment that they would be there at extremely low levels, as such the most sensitive method available for the detection of PrPSc, serial Protein Misfolding Cyclic Amplification (sPMCA), was used in this study. We investigated the distribution of environmental scrapie prions by applying ovine sPMCA to samples taken from a range of surfaces that were accessible to animals and could be collected by use of a wetted foam swab. Prion was amplified by sPMCA from a number of these environmental swab samples including those taken from metal, plastic and wooden surfaces, both in the indoor and outdoor environment. At the time of sampling there had been no sheep contact with these areas for at least 20 days prior to sampling indicating that prions persist for at least this duration in the environment. These data implicate inanimate objects as environmental reservoirs of prion infectivity which are likely to contribute to disease transmission.
 
 
2012
 
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer
 
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA
 
snip...
 
The results of this study suggest that there are many similarities in the manifestation of CWD and scrapie in WTD after IC inoculation including early and widespread presence of PrPSc in lymphoid tissues, clinical signs of depression and weight loss progressing to wasting, and an incubation time of 21-23 months. Moreover, western blots (WB) done on brain material from the obex region have a molecular profile similar to CWD and distinct from tissues of the cerebrum or the scrapie inoculum. However, results of microscopic and IHC examination indicate that there are differences between the lesions expected in CWD and those that occur in deer with scrapie: amyloid plaques were not noted in any sections of brain examined from these deer and the pattern of immunoreactivity by IHC was diffuse rather than plaque-like.
 
*** After a natural route of exposure, 100% of WTD were susceptible to scrapie.
 
Deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 months PI. Tissues from these deer were positive for PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer exhibited two different molecular profiles: samples from obex resembled CWD whereas those from cerebrum were similar to the original scrapie inoculum. On further examination by WB using a panel of antibodies, the tissues from deer with scrapie exhibit properties differing from tissues either from sheep with scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are strongly immunoreactive when probed with mAb P4, however, samples from WTD with scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4 or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly immunoreactive and samples from WTD with scrapie are strongly positive. This work demonstrates that WTD are highly susceptible to sheep scrapie, but on first passage, scrapie in WTD is differentiable from CWD.
 
 
2011
 
*** After a natural route of exposure, 100% of white-tailed deer were susceptible to scrapie.
 
 
*** We hypothesize that both BSE prions and CWD prions passaged through felines will seed human recPrP more efficiently than BSE or CWD from the original hosts, evidence that the new host will dampen the species barrier between humans and BSE or CWD. The new host effect is particularly relevant as we investigate potential means of trans-species transmission of prion disease.
 
 
Veterinary Pathology Onlinevet.sagepub.com Published online before print February 27, 2014, doi: 10.1177/0300985814524798 Veterinary Pathology February 27, 2014 0300985814524798
 
Lesion Profiling and Subcellular Prion Localization of Cervid Chronic Wasting Disease in Domestic Cats
 
D. M. Seelig1⇑ A. V. Nalls1 M. Flasik2 V. Frank1 S. Eaton2 C. K. Mathiason1 E. A. Hoover1 1Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA 2Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA D. M. Seelig, University of Minnesota, Department of Veterinary Clinical Sciences, Room 339 VetMedCtrS, 6192A (Campus Delivery Code), 1352 Boyd Ave, St Paul, MN 55108, USA. Email address: dseelig@umn.edu
 
Abstract
 
Chronic wasting disease (CWD) is an efficiently transmitted, fatal, and progressive prion disease of cervids with an as yet to be fully clarified host range. While outbred domestic cats (Felis catus) have recently been shown to be susceptible to experimental CWD infection, the neuropathologic features of the infection are lacking. Such information is vital to provide diagnostic power in the event of natural interspecies transmission and insights into host and strain interactions in interspecies prion infection. Using light microscopy and immunohistochemistry, we detail the topographic pattern of neural spongiosis (the “lesion profile”) and the distribution of misfolded prion protein in the primary and secondary passage of feline CWD (FelCWD). We also evaluated cellular and subcellular associations between misfolded prion protein (PrPD) and central nervous system neurons and glial cell populations. From these studies, we (1) describe the novel neuropathologic profile of FelCWD, which is distinct from either cervid CWD or feline spongiform encephalopathy (FSE), and (2) provide evidence of serial passage-associated interspecies prion adaptation. In addition, we demonstrate through confocal analysis the successful co-localization of PrPD with neurons, astrocytes, microglia, lysosomes, and synaptophysin, which, in part, implicates each of these in the neuropathology of FelCWD. In conclusion, this work illustrates the simultaneous role of both host and strain in the development of a unique FelCWD neuropathologic profile and that such a profile can be used to discriminate between FelCWD and FSE.
 
prion chronic wasting disease immunohistochemistry interspecies cat feline spongiform encephalopathy transmissible spongiform encephalopathy adaptation species barrier
 
 
Sunday, March 09, 2014
 
Lesion Profiling and Subcellular Prion Localization of Cervid Chronic Wasting Disease in Domestic Cats
 
 
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.
 
 
 
AD.63:
 
Susceptibility of domestic cats to chronic wasting disease
 
Amy V.Nalls,1 Candace Mathiason,1 Davis Seelig,2 Susan Kraft,1 Kevin Carnes,1 Kelly Anderson,1 Jeanette Hayes-Klug1 and Edward A. Hoover1 1Colorado State University; Fort Collins, CO USA; 2University of Minnesota; Saint Paul, MN USA
 
Domestic and nondomestic 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 nondomestic 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 5 cats each were inoculated either intracerebrally (IC) or orally (PO) with CWD-infected deer brain. At 40 and 42 mo 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 mo. Brains from these two cats were pooled and inoculated into cohorts of cats by IC, PO, and intraperitoneal and subcutaneous (IP/SC) routes. Upon subpassage, feline-adapted CWD (FelCWD) was transmitted to all IC-inoculated cats with a decreased incubation period of 23 to 27 mo. FelCWD was detected in the brains of all the symptomatic cats by western blotting and immunohistochemistry and abnormalities were seen in magnetic resonance imaging, including multifocal T2 fluid attenuated inversion recovery (FLAIR) signal hyper-intensities, ventricular size increases, prominent sulci, and white matter tract cavitation. Currently, 3 of 4 IP/SQ and 2 of 4 PO inoculared 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.
 
 
www.landesbioscience.com
 
PO-081: Chronic wasting disease in the cat— Similarities to feline spongiform encephalopathy (FSE)
 
 
 
FELINE SPONGIFORM ENCEPHALOPATHY FSE
 
 
 
From: Terry S. Singeltary Sr.
 
Sent: Sunday, October 12, 2014 2:15 PM
 
Subject: CWD TSE PRION, TISSUE, BODY FLUIDS, AND ENVIRONMENTAL CONTAMINATION
 
Quantitative Assessment of Prion Infectivity in Tissues and Body Fluids by RT-QuIC
 
Davin M. Henderson1, Kristen A. Davenport1, Nicholas J. Haley2, Nathaniel D. Denkers1, Candace K. Mathiason1 and Edward A. Hoover Jr1,3
 
+ Author Affiliations 1 Prion Research Center, Colorado State University, USA; 2 Department of Diagnostic Medicine and Pathobiology, Kansas State University, USA ↵3 E-mail: edward.hoover@colostate.edu Received 8 July 2014. Accepted 6 October 2014.
 
Abstract
 
Prions are amyloid-forming proteins that cause transmissible spongiform encephalopathies through a process involving the templated conversion of the normal cellular prion protein (PrPC) to a pathogenic misfolded conformation. Templated conversion has been modeled in several in vitro assays, including serial protein misfolding amplification (sPMCA), amyloid seeding, and real time quaking induced conversion (RT-QuIC). Because RT-QuIC measures formation of amyloid fibrils in real time, it can be used to estimate the rate of seeded conversion. Here we use samples from deer infected with chronic wasting disease (CWD) in RT-QuIC to show that serial dilution of prion seed is linearly related to the rate of amyloid formation over a range of 10-3 to 10-8 µg. We then used an amyloid formation rate standard curve derived from a bioassayed reference sample (CWD+ brain homogenate) to estimate the prion seed concentration and infectivity in tissues, body fluids and excreta. Using these methods we estimate that urine and saliva from CWD-infected deer contain between 1 and 5 LD50 per 10 ml, respectively. Thus, over the 1 to 2 year course of infection, a substantial environmental reservoir of CWD prion contamination accumulates.
 
Amyloid Quantitation CWD Prion RT-QuIC TSE
 
 
P.141: Abundant prion shedding in CWD-infected deer revealed by Realtime conversion
 
Edward A Hoover,1 Davin M Henderson,1 Nathaniel D Denkers,1 Candace K Mathiason,1 Matteo Manca,2,3 and Byron Caughey2
 
1Prion Research Center, Colorado State University; Fort Collins, CO USA; 2Laboratory of Persistent Viral Diseases, NI AID; Hamilton, MT USA; 3Department of Biomedical Sciences, University of Cagliari; Monserrato, Italy
 
Background/Introduction. Chronic wasting disease (CWD) is unique among prion diseases in its efficient lateral transmission in nature. While the presence of infectious prions in body fluids and excreta of infected cervids has been demonstrated by bioassay, the dynamics, magnitude, and consequences of prion shedding remain unknown. The present studies were undertaken to determine the kinetics, duration, and magnitude of prion shedding in infected white-tailed deer.
 
Materials and Methods. Longitudinal samples were collected from white-tailed deer over a 2-year span after either oral (n=11)] aerosol (n = 6) CWD exposure. The assay protocol employed phosphotungstic acid precipitation of either whole saliva or the pelleted fraction of urine to seed recombinant Syrian hamster prion PrP substrate in RT-QuIC reactions. Prion seeding activity was assayed in 8 replicates of each sample employing thioflavin T detection in a 96-well plate-based fluorometer. Prion seeding reaction rate was determined by taking the inverse of the time at which samples exceeded a threshold of 5 standard deviations above the mean fluorescence of negative controls (1/time to threshold). Seeding activity was quantitated by comparing the realtime conversion reaction rate to a standard curve derived from a reference bioassayed brain pool homogenate from deer with terminal CWD.
 
Results. We analyzed >200 longitudinally collected, blinded, then randomized saliva and urine samples from 17 CWDinfected and 3 uninfected white-tailed deer. We detected prion shedding as early as 3 months post exposure and sustained thereafter throughout the disease course in both aerosol and orally exposed deer. The incidence of non-specific false positive results from >500 saliva and urine samples from negative control deer was 0.8%. By comparing real-time reaction rates for these body fluids to a bioassayed serially diluted brain control, we estimated that ≤1 ml of saliva or urine from pre-symptomatic infected deer constitutes a lethal infectious prion dose.
 
Conclusion. CWD prions are shed in saliva and urine of infected deer as early as 3 months post infection and throughout the subsequent >1.5 year course of infection. In current work we are examining the relationship of prionemia to excretion and the impact of excreted prion binding to surfaces and particulates in the environment.
 
Acknowledgments. Support: NIH-RO1-NS-061902; Morris Animal Foundation D12ZO-045
 
P.154: Urinary shedding of prions in Chronic Wasting Disease infected white-tailed deer
 
Nathaniel D Denkers,1 Davin M Henderson, 1 Candace K Mathiason,1 and Edward A Hoover1 1Prion Research Center, Department of Microbiology, Immunology, and Pathology, Colorado State University; Fort Collins, CO USA
 
Background/Introduction. Chronic wasting disease (CWD) is unique among prion diseases in its efficient lateral transmission in nature, yet the dynamics and magnitude of shedding and its immediate and long term consequences remain unknown. The present study was designed to determine the frequency and time span in which CWD prions are shed in urine from infected white-tailed deer using adapted real-time quaking-induced conversion (RT-QuIC) methodology.
 
Materials and Methods. Longitudinal urine samples were collected by free catch or catheterization over a 2-year period from oral-route infected [CWD+ (n = 11)] and aerosol-route-infected [CWD+ (n = 6); CWD- (n = 3)] white-tailed deer. High speed centrifugation pelleted material from 500 µl of urine was treated with sodium phosphotungstic acid (Na-PTA), resuspended in 0.05% SDS buffer, and used as seed in RT-QuIC assays employing recombinant Syrian hamster prion PrP substrate. Eight (8) replicates of each sample were run and prion seeding activity was recorded as thioflavin T binding fluorescence (480 nm emission) using a fluorimeter-shaker. Samples were considered positive if they crossed an established threshold (5 standard deviations above the negative mean fluorescence).
 
Results. In our oral-route inoculation studies, prion seeding activity has been demonstrated in urine collected at 6 months post-inoculation in 6 of 10 deer (11 of 80 replicates; 14%), and intermittently at later time points in all 11 CWD+ exposed deer. Our aerosol-route inoculation studies also showed prion seeding activity in urine collected at 6 months post-inoculation in 1 of 2 deer (3 of 16 replicates; 19%), and intermittently at later time points in 4 of 6 CWD+ exposed deer. Urine from sham-inoculated control deer and all baseline samples yielded 3 false-positive prion seeding activities (3 of 352 replicates; 0.8%).
 
Conclusion. CWD prions (as inferred by prion seeding activity by RT-QuIC) are shed in urine of infected deer as early as 6 months post inoculation and throughout the subsequent disease course. Further studies are in progress refining the real-time urinary prion assay sensitivity and we are examining more closely the excretion time frame, magnitude, and sample variables in relationship to inoculation route and prionemia in naturally and experimentally CWD-infected cervids.
 
Acknowledgments. Support: NIH: RO1-NS-061902 and Morris Animal Foundation: D12ZO-045
 
P.121: Efficient transmission of prion disease through environmental contamination
 
Sandra Pritzkow, Rodrigo Morales, and Claudio Soto Mitchell Center for Alzheimer’s disease and related Brain disorders; University of Texas Medical School at Houston; Hourston, TX USA
 
Chronic wasting disease (CWD) is a prion disorder effecting captive and free-ranging deer and elk. The efficient propagation suggests that horizontal transmission through contaminated environment may play an important role. It has been shown that infectious prions enter the environment through saliva, feces, urine, blood or placenta tissue from infected animals, as well as by carcasses from diseased animals and can stay infectious inside soil over several years.
 
We hypothesize that environmental components getting in contact with infectious prions can also play a role for the horizontal transmission of prion diseases. To study this issue, surfaces composed of various environmentally relevant materials were exposed to infectious prions and the attachment and retention of infectious material was studied in vitro and in vivo. We analyzed polypropylene, glass, stainless steel, wood, stone, aluminum, concrete and brass surfaces exposed to 263K-infected brain homogenate. For in vitro analyses, the material was incubated in serial dilutions of 263K-brain homogenate, washed thoroughly and analyzed for the presence of PrPSc by PMCA. The results show that even highly diluted PrPSc can bind efficiently to polypropylene, stainless steel, glass, wood and stone and propagate the conversion of normal prion protein. For in vivo experiments, hamsters were ic injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters, inoculated with 263K-contaminated implants of all groups, developed typical signs of prion disease, whereas control animals inoculated with non-contaminated materials did not.
 
In addition, in order to study the transmission in a more natural setting, we exposed a group of hamster to habit in the presence of spheres composed of various materials that were pretreated with 263K prions. Many of the hamsters exposed to these contaminated materials developed typical signs of the disease that were confirmed by immunohistological and biochemical analyses.
 
These findings suggest that various surfaces can efficiently bind infectious prions and act as carriers of infectivity, suggesting that diverse elements in the environment may play an important role in horizontal prion transmission.
 
P.138: Phenotypic diversity in meadow vole (Microtus pennsylvanicus) prion diseases following challenge with chronic wasting disease isolates
 
Christopher J Johnson,1 Christina M Carlson,1,2 Jay R Schneider,1 Jamie K Wiepz,1 Crystal L Meyerett-Reid,3 Mark D Zabel,3 Joel A Pedersen,2 and Dennis M Heisey1 1USGS National Wildlife Health Center; Madison, WI USA; 2University of Wisconsin— Madison; Madison, WI USA; 3Colorado State University; Fort Collins, CO USA
 
Chronic wasting disease (CWD), a prion disease of cervids (deer, elk and moose), is spreading unchecked through large sections of North America. Transmission of CWD among cervids is especially facile and can occur through direct animal-toanimal contact and indirectly through contact with prions shed from infected animals. The disease transmission threat posed by CWD to other wildlife species remains unknown, but other species are inevitably exposed to CWD by consumption of infectious materials and through contact with environmental CWD contamination. In this study, we investigated the transmission and adaptation of various white-tailed deer CWD isolates in the meadow vole (Microtus pennsylvanicus), a native North American rodent that is sympatric with current CWD epizootics that we have previously established is susceptible to CWD. We found that serial subpassage of CWD from white-tailed deer homozygous for glycine at position 96 (96GG) of the prion protein in meadow voles resulted in the selection of a single prion strain that was characterized by homogeneity in incubation period, abnormal prion protein (PrPTSE) glycoform ratio, lesion profile and PrPTSE deposition pattern. In contrast, passage of CWD from heterozygous 96GS genotype deer produced four unique disease phenotypes upon first passage. Subpassage of these types ultimately resulted in selection of a single strain by third passage that was distinct from the 96GG genotype CWD-derived strain. We also establish that meadow voles are susceptible to CWD via peripheral challenge, albeit with lower attack rates and longer incubation periods. Interestingly, oral challenge of meadow voles with CWD resulted in subclinical infection in primary passage animals, but manifested as clinical prion disease upon subpassage. Our data establish that meadow voles are permissive to CWD via peripheral exposure route, suggesting they could serve as an environmental reservoir for CWD. Additionally, our data are consistent with the hypothesis that at least two strains of CWD circulate in naturally-infected cervid populations and provide evidence that meadow voles are a useful tool for CWD strain typing.
 
P.146: Kinetics and cell association of chronic wasting disease prions shed in saliva and urine of white-tailed deer
 
Nicholas J Haley,1,2 Scott Carver,3 Clare E Hoover,1 Kristen A Davenport,1 Candace K Mathiason,1 Glenn C Telling,1 and Edward A Hoover1
 
1Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences; Colorado State University; Fort Collins, CO USA; 2Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine; Kansas State University; Manhattan, KS USA; 3School of Zoology; University of Tasmania; Hobart, Tasmania, Australia
 
Chronic wasting disease, a transmissible spongiform encephalopathy (TSE) of deer, elk, and moose, is unique among prion diseases in its relatively efficient horizontal transmissibility. Recent studies have shown that excreta—saliva, urine, and feces—from CWD-positive cervids may play an important role in horizontal transmission of CWD, and although the precise onset of shedding in these excreta is unknown, it is thought to occur long before the onset of clinical symptoms. High levels of prion seeding activity have been demonstrated in excretory tissues of deer, including tongue, salivary glands, kidney, and urinary bladder, though the origin(s) and cellular nature of infectious prions in excreta is unknown. We hypothesized that excretory shedding of CWD prions in saliva and urine would coincide with the appearance of PrPd appearance in peripheral lymphatic tissues, and that infectivity would associate with cellular preparations of these excreta. Following intracerebral inoculation of susceptible Tg[CerPrP] mice, we observed efficient transmission in saliva collected as early as 12 months post-exposure, coinciding with peripheral PrPd appearance in tonsil biopsies; while urine collected at terminal disease was only minimally infectious in transgenic mice. We also found that acellular preparations of saliva, and cellular preparations of urine, were capable of transmitting CWD infection to transgenic Tg[CerPrP] mice with incubation periods similar to that of whole saliva or urine; saliva and urine from CWD-negative deer failed to induce prion disease in these mice. Infectious titers were determined for obex and bodily fluids, and were similar to those previously described. These findings extend our understanding of CWD shedding in white-tailed deer, and offer insight into the source and cellular associations of infectious CWD prions in excreta.
 
P.178: Longitudinal quantitative analysis of CWD prions shed in saliva of deer
 
Davin M Henderson, Nina Garbino, Nathaniel D Denkers, Amy V Nalls, Candace K Mathiason, and Edward A Hoover Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University; Fort Collins, CO USA
 
Background/Introduction. Chronic Wasting Disease (CWD) is an emergent rapidly spreading fatal prion disease of cervids (deer, elk and moose). CWD has now been identified in 22 States (including two new states within the last year), 2 Canadian provinces, and South Korea. Shedding of infectious prions in excreta (saliva, urine, feces) may be an important factor in CWD transmission. Here we apply an adapted version of a rapid in vitro assay [real-time quaking-induced conversion (RT-QuIC)] to determine the time of onset, length, pattern, and magnitude of prion shedding in saliva of infected deer.
 
Materials and Methods. The RT-QuIC assay was performed as previously described in Henderson et al. PLoS-One (2013). Saliva samples were quantitated by comparison to a RT-QuIC reaction rate standard curve of a bioassayed obex sample from a terminally ill cervid.
 
Results. To better understand the onset and length of CWD prion shedding we analyzed >150 longitudinally collected, blinded, then randomized saliva samples from 17 CWD-infected and 3 uninfected white-tailed deer. We observed prion shedding, as detected by the RT-QuIC assay, as early as 3 months from inoculation and sustained shedding throughout the disease course in both aerosol and orally exposed deer. We estimated the infectious lethal dose of prions shed in saliva from infected deer by comparing real-time reaction rates of saliva samples to a bioassayed serially diluted brain control. Our results indicate that as little as 1 ml of saliva from pre-symptomatic infected deer constitutes a lethal CWD prion dose.
 
Conclusions. During the pre-symptomatic stage of CWD infection and throughout the course of disease deer may be shedding multiple LD50 doses per day in their saliva. CWD prion shedding through saliva and excreta may account for the unprecedented spread of this prion disease in nature. Acknowledgments. Supported by NIH grant RO1-NS-061902 and grant D12ZO-045 from the Morris Animal Foundation.
 
 
*** We conclude that TSE infectivity is likely to survive burial for long time periods with minimal loss of infectivity and limited movement from the original burial site. However PMCA results have shown that there is the potential for rainwater to elute TSE related material from soil which could lead to the contamination of a wider area. These experiments reinforce the importance of risk assessment when disposing of TSE risk materials.
 
*** The results show that even highly diluted PrPSc can bind efficiently to polypropylene, stainless steel, glass, wood and stone and propagate the conversion of normal prion protein. For in vivo experiments, hamsters were ic injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters, inoculated with 263K-contaminated implants of all groups, developed typical signs of prion disease, whereas control animals inoculated with non-contaminated materials did not.
 
PRION 2014 CONFERENCE
 
CHRONIC WASTING DISEASE CWD
 
A FEW FINDINGS ;
 
Conclusions. To our knowledge, this is the first established experimental model of CWD in TgSB3985. We found evidence for co-existence or divergence of two CWD strains adapted to Tga20 mice and their replication in TgSB3985 mice. Finally, we observed phenotypic differences between cervid-derived CWD and CWD/Tg20 strains upon propagation in TgSB3985 mice. Further studies are underway to characterize these strains.
 
We conclude that TSE infectivity is likely to survive burial for long time periods with minimal loss of infectivity and limited movement from the original burial site. However PMCA results have shown that there is the potential for rainwater to elute TSE related material from soil which could lead to the contamination of a wider area. These experiments reinforce the importance of risk assessment when disposing of TSE risk materials.
 
The results show that even highly diluted PrPSc can bind efficiently to polypropylene, stainless steel, glass, wood and stone and propagate the conversion of normal prion protein. For in vivo experiments, hamsters were ic injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters, inoculated with 263K-contaminated implants of all groups, developed typical signs of prion disease, whereas control animals inoculated with non-contaminated materials did not.
 
Our data establish that meadow voles are permissive to CWD via peripheral exposure route, suggesting they could serve as an environmental reservoir for CWD. Additionally, our data are consistent with the hypothesis that at least two strains of CWD circulate in naturally-infected cervid populations and provide evidence that meadow voles are a useful tool for CWD strain typing.
 
Conclusion. CWD prions are shed in saliva and urine of infected deer as early as 3 months post infection and throughout the subsequent >1.5 year course of infection. In current work we are examining the relationship of prionemia to excretion and the impact of excreted prion binding to surfaces and particulates in the environment.
 
Conclusion. CWD prions (as inferred by prion seeding activity by RT-QuIC) are shed in urine of infected deer as early as 6 months post inoculation and throughout the subsequent disease course. Further studies are in progress refining the real-time urinary prion assay sensitivity and we are examining more closely the excretion time frame, magnitude, and sample variables in relationship to inoculation route and prionemia in naturally and experimentally CWD-infected cervids.
 
Conclusions. Our results suggested that the odds of infection for CWD is likely controlled by areas that congregate deer thus increasing direct transmission (deer-to-deer interactions) or indirect transmission (deer-to-environment) by sharing or depositing infectious prion proteins in these preferred habitats. Epidemiology of CWD in the eastern U.S. is likely controlled by separate factors than found in the Midwestern and endemic areas for CWD and can assist in performing more efficient surveillance efforts for the region.
 
Conclusions. During the pre-symptomatic stage of CWD infection and throughout the course of disease deer may be shedding multiple LD50 doses per day in their saliva. CWD prion shedding through saliva and excreta may account for the unprecedented spread of this prion disease in nature.
 
see full text and more ;
 
Monday, June 23, 2014
 
*** PRION 2014 CONFERENCE CHRONIC WASTING DISEASE CWD
 
 
 
*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years***
 
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
 
 
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
 
 
Karen Fernie, Allister Smith and Robert A. Somerville The Roslin Institute and R(D)SVS; University of Edinburgh; Roslin, Scotland UK
 
Scrapie and chronic wasting disease probably spread via environmental routes, and there are also concerns about BSE infection remaining in the environment after carcass burial or waste 3disposal. In two demonstration experiments we are determining survival and migration of TSE infectivity when buried for up to five years, as an uncontained point source or within bovine heads. Firstly boluses of TSE infected mouse brain were buried in lysimeters containing either sandy or clay soil. Migration from the boluses is being assessed from soil cores taken over time. With the exception of a very small amount of infectivity found 25 cm from the bolus in sandy soil after 12 months, no other infectivity has been detected up to three years. Secondly, ten bovine heads were spiked with TSE infected mouse brain and buried in the two soil types. Pairs of heads have been exhumed annually and assessed for infectivity within and around them. After one year and after two years, infectivity was detected in most intracranial samples and in some of the soil samples taken from immediately surrounding the heads. The infectivity assays for the samples in and around the heads exhumed at years three and four are underway. These data show that TSE infectivity can survive burial for long periods but migrates slowly. Risk assessments should take into account the likely long survival rate when infected material has been buried.
 
The authors gratefully acknowledge funding from DEFRA.
 
 
 
Sunday, November 3, 2013
 
*** Environmental Impact Statements; Availability, etc.: Animal Carcass Management [Docket No. APHIS-2013-0044] ***
 
 
Sunday, July 07, 2013
 
*** Could avian scavengers translocate infectious prions to disease-free areas initiating new foci of chronic wasting disease? Prion. 2013 Jul 3;7(4). [Epub ahead of print]
 
 
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
 
 
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.
 
 
Monday, March 26, 2012
 
CANINE SPONGIFORM ENCEPHALOPATHY: A NEW FORM OF ANIMAL PRION DISEASE
 
 
2005
 
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
 
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
 
======================================
 
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, indentify the three brains that were from the ''POSITIVE'' end of the lesion spectrum.
 
 
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.
 
snip...
 
 
76 pages on hound study;
 
snip...
 
 
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.
 
snip...
 
 
NEW URL ;
 
 
Friday, March 8, 2013
 
Dogs may have been used to make Petfood and animal feed
 
 
 
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.
 
 
Monday, March 8, 2010
 
Canine Spongiform Encephalopathy aka MAD DOG DISEASE
 
 
Singeltary Submission TAHC on CWD rule proposal
 
Saturday, July 07, 2012
 
TEXAS Animal Health Commission Accepting Comments on Chronic Wasting Disease Rule Proposal
 
Considering the seemingly high CWD prevalence rate in the Sacramento and Hueco Mountains of New Mexico, CWD may be well established in the population and in the environment in Texas at this time.
 
 
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...
 
 
NEW URL LINK ;
 
 
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
 
 
Thursday, October 23, 2014
 
*** FIRST CASE OF CHRONIC WASTING DISEASE CONFIRMED IN OHIO ON PRIVATE PRESERVE
 
 
Tuesday, October 21, 2014
 
*** Pennsylvania Department of Agriculture Tenth Pennsylvania Captive Deer Tests Positive for Chronic Wasting Disease CWD TSE PRION DISEASE
 
 
Tuesday, October 07, 2014
 
*** Wisconsin white-tailed deer tested positive for CWD on a Richland County breeding farm, and a case of CWD has been discovered on a Marathon County hunting preserve
 
 
Thursday, October 02, 2014
 
*** IOWA TEST RESULTS FROM CAPTIVE DEER HERD WITH CHRONIC WASTING DISEASE RELEASED 79.8 percent of the deer tested positive for the disease
 
 
Tuesday, November 04, 2014
 
N.C. Wildlife Resources Commission Revisions Made to Captive Cervid Licenses and Permits
 
 
Saturday, September 20, 2014
 
*** North Carolina Captive cervid licenses and permits Senate Bill 744 Singeltary Submission
 
 
Friday, October 21, 2011
 
Chronic Wasting Disease Found in Captive Deer Missouri
 
 
The Missouri Department of Agriculture discovers the state's first case of CWD in a captive white-tailed deer.
 
 
Thursday, July 03, 2014
 
*** How Chronic Wasting Disease is affecting deer population and what’s the risk to humans and pets?
 
 
Tuesday, July 01, 2014
 
*** CHRONIC WASTING DISEASE CWD TSE PRION DISEASE, GAME FARMS, AND POTENTIAL RISK FACTORS THERE FROM
 
 
cwd, international trade, spreading it around by interstate or National movement
 
spreading cwd around
 
Between 1996 and 2002, chronic wasting disease was diagnosed in 39 herds of farmed elk in Saskatchewan in a single epidemic. All of these herds were depopulated as part of the Canadian Food Inspection Agency’s (CFIA) disease eradication program. Animals, primarily over 12 mo of age, were tested for the presence CWD prions following euthanasia. Twenty-one of the herds were linked through movements of live animals with latent CWD from a single infected source herd in Saskatchewan, 17 through movements of animals from 7 of the secondarily infected herds.
 
***The source herd is believed to have become infected via importation of animals from a game farm in South Dakota where CWD was subsequently diagnosed (7,4). A wide range in herd prevalence of CWD at the time of herd depopulation of these herds was observed. Within-herd transmission was observed on some farms, while the disease remained confined to the introduced animals on other farms.
 
 
spreading cwd around
 
Friday, May 13, 2011
 
Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea 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.
 
 
 
 
*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies.
 
 
cwd exposure, and iatrogenic CJD, what if ???
 
*** our results raise the possibility that CJD cases classified as VV1 may include cases caused by iatrogenic transmission of sCJD-MM1 prions or food-borne infection by type 1 prions from animals, e.g., chronic wasting disease prions in cervid. In fact, two CJD-VV1 patients who hunted deer or consumed venison have been reported (40, 41). The results of the present study emphasize the need for traceback studies and careful re-examination of the biochemical properties of sCJD-VV1 prions. ***
 
 
snip...see full text ;
 
 
Thursday, January 2, 2014
 
*** CWD TSE Prion in cervids to hTGmice, Heidenhain Variant Creutzfeldt-Jacob Disease MM1 genotype, and iatrogenic CJD ??? ***
 
 
*** We hypothesize that both BSE prions and CWD prions passaged through felines will seed human recPrP more efficiently than BSE or CWD from the original hosts, evidence that the new host will dampen the species barrier between humans and BSE or CWD. The new host effect is particularly relevant as we investigate potential means of trans-species transmission of prion disease.
 
 
Tuesday, November 04, 2014
 
*** Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: risk behaviours and health outcomes 2005–2011
 
 
Tuesday, November 04, 2014
 
Towards an Age-Dependent Transmission Model of Acquired and Sporadic Creutzfeldt-Jakob Disease
 
 
 
*** URGENT UPDATE ***
 
Friday, December 5, 2014
 
*** SPECIAL ALERT The OIE recommends strengthening animal disease surveillance worldwide ***
 
OIE BSE TSE PRION AKA MAD COW DISEASE ?
 
‘’the silence was deafening’’ ...tss
 
 
 
Saturday, December 13, 2014
 
Terry S. Singeltary Sr. Publications TSE prion disease
 
for my files...tss
 
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
 
Singeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA
 
snip...
 
 
 
 
TSS
 

posted by Terry S. Singeltary Sr. at 3:48 PM

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