WISCONSIN CHRONIC WASTING DISEASE CWD SAMPLING UPDATE
Subject: WISCONSIN CHRONIC WASTING DISEASE CWD SAMPLING UPDATE
CWD sampling plan in place for Adams, Juneau, Portage, Marathon and Waushara counties for 2017-18 deer hunting season
WISCONSIN RAPIDS, Wis. - In cooperation with local businesses, Wisconsin Department of Natural Resources staff are collecting deer heads for chronic wasting disease surveillance testing within Adams, Juneau, Portage, Marathon and Waushara counties during the 2017 archery, crossbow and gun hunting seasons.
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Central Office
Wednesday, September 27, 2017 3:23:35 p.m.
CWD sampling plan in place for south central and south western Wisconsin for 2017-18 deer hunting seasonWednesday, September 27, 2017 3:23:35 p.m.
MADISON - In cooperation with local businesses, Wisconsin Department of Natural Resources staff collect deer heads for chronic wasting disease surveillance testing within Richland, Grant, Sauk, Iowa, Lafayette, Columbia, Dane, Green and Rock counties during the 2017 archery, crossbow and gun hunting seasons.
Central Office
Wednesday, September 27, 2017 3:20:48 p.m.
Targeted CWD surveillance efforts ramping up in Oneida, Forest and Vilas countiesWednesday, September 27, 2017 3:20:48 p.m.
RHINELANDER, Wis. - In cooperation with local businesses, the Wisconsin Department of Natural Resources will collect deer heads for chronic wasting disease surveillance testing Oneida, Vilas and Forest counties during the 2017 archery, crossbow and gun hunting seasons.
Central Office
Wednesday, September 27, 2017 3:17:01 p.m.
CWD sampling plan in place for Barron, Burnett, Polk and Washburn counties for 2017 deer hunting seasonsWednesday, September 27, 2017 3:17:01 p.m.
SPOONER, Wis. - In cooperation with local businesses, the Wisconsin Department of Natural Resources will collect deer heads for chronic wasting disease surveillance testing within Barron, Burnett, Polk and Washburn counties during the 2017 archery, crossbow and gun hunting seasons.
Central Office
Wednesday, September 27, 2017 3:15:04 p.m.
CWD sampling plan in place for Eau Claire, Clark and Jackson counties for 2017 deer hunting seasonsWednesday, September 27, 2017 3:15:04 p.m.
EAU CLAIRE, Wis. - In cooperation with local businesses, the Wisconsin Department of Natural Resources will collect deer heads for chronic wasting disease surveillance testing during the 2017 archery, crossbow and gun hunting seasons.
Central Office
Wednesday, September 27, 2017 3:13:07 p.m.
Targeted CWD surveillance efforts ramping up in Oconto, Shawano, and Menominee countiesWednesday, September 27, 2017 3:13:07 p.m.
RHINELANDER, Wis. - In cooperation with local businesses, the Wisconsin Department of Natural Resources will collect deer heads for chronic wasting disease surveillance testing from Oconto, Shawano and Menominee counties during the 2017 archery, crossbow and gun hunting seasons. In particular, a 10-mile surveillance area has been identified.
Central Office
Wednesday, September 27, 2017 3:09:54 p.m.
CWD sampling plan in place for southeastern Wisconsin for 2017-18 deer hunting seasonWednesday, September 27, 2017 3:09:54 p.m.
MADISON - In cooperation with local businesses, Department of Natural Resources staff will focus on collecting deer heads for chronic wasting disease surveillance testing within Dodge, Jefferson, Walworth, Washington, Ozaukee, Waukesha, Racine, Kenosha and Milwaukee counties during the 2017 archery, crossbow and gun hunting seasons.
Central Office
Wednesday, September 27, 2017 3:08:31 p.m.
Wednesday, September 27, 2017 3:08:31 p.m.
CWD sampling areas for 2017
DNR urges hunters to get deer tested for CWD
Paul A. Smith,
Milwaukee Journal Sentinel Published 3:30 p.m. CT Sept. 30, 2017 636422840125626549-CWD-WDNR-2017-surveillance-plan.jpg (Photo: Wisconsin Department of Natural Resources)
As the 2017 Wisconsin deer hunting seasons ramp up, the Department of Natural Resources is encouraging hunters to get harvested deer tested for chronic wasting disease.
Sampling efforts are aimed at learning more about the disease intensity and distribution in CWD-affected regions as well as detecting new sites of infection.
Hunters are asked to submit heads of adult deer at participating businesses, including taxidermy shops, or at DNR kiosks and service centers.
The testing is voluntary and free of charge.
The agency is conducting "targeted surveillance" for the disease this year in several areas of the state, including in Oneida, Forest and Vilas counties.
The efforts in northern Wisconsin are in response to CWD-positive deer killed at a shooting preserve near Three Lakes in Oneida County.
The initial diseased deer was killed in November 2015; subsequent testing has found seven CWD-positive deer out of 30 tested on the captive facility, according to the DNR.
Twenty-four other counties also are slated for increased CWD testing this year.
But hunters anywhere in the state may submit deer heads for testing.
In 2016, the DNR tested 6,129 samples for testing; 7% were positive.
The agency spent $406,924 for CWD testing in fiscal year 2016. The cost of testing to the state was about $80 per deer, according to the DNR.
Funding for CWD testing comes from the sale of bonus antlerless deer tags and the Federal Aid in Wildlife Restoration Fund.
Chronic wasting disease is fatal to deer and elk and is caused by an abnormal prion, or protein.
The disease is contagious and thought to be transmitted mainly through saliva and other bodily fluids. But the prion also persists in the environment, allowing indirect transmission.
Afflicted animals suffer damage to the brain and central nervous system and in advanced stages become emaciated.
The disease was first identified in Colorado in 1967; it has since spread to at least 23 states. The first Wisconsin cases of CWD were detected in 2002.
The disease is a transmissible spongiform encephalopathy, a family that includes scrapie as well as mad cow disease and Creutzfeldt-Jakob (both of which are fatal to humans).
While CWD has not been documented to cause illness in humans, health experts, including at the U.S. Centers for Disease Control, have long issued strong advice against eating venison from CWD-positive animals.
Since 2003 the Wisconsin Division of Public Health has published the following guidance: "Venison from deer harvested inside the CWD Management Zone should not be consumed or distributed to others until CWD test results on the sources deer are known to be negative."
Join now for as low as 99¢/1st month Subscribe Now The Wisconsin recommendation says venison from multiple deer should be kept separate and labeled before freezing so any meat from a CWD-positive animal can be discarded.
The DNR has posted guidelines for safe venison handling on its website at dnr.wi.gov/topic/wildlifehabitat/documents/Venison_CWD.pdf.
The agency also has published a list of recommendations to limit or prevent the spread of CWD.
They include: preventing unnaturally high concentrations of deer; securely bagging deer carcasses and disposing in a landfill; decontaminating knives and other tools used to process deer.
In southeastern Wisconsin, deer heads may be dropped off at locations including Whale Tales Archery in Dousman, Brehm Taxidermy in East Troy and Artisan Taxidermy in Burlington, as well as at 24-hour, self-service kiosks at DNR offices in Eagle, Hartford, Horicon, Kansasville and Lake Mills.
The DNR has a complete list of sampling and drop-off locations on its website.
2017
Subject: ***CDC Now Recommends Strongly consider having the deer or elk tested for CWD before you eat the meat
CDC Now Recommends Strongly consider having the deer or elk tested for CWD before you eat the meat
Chronic Wasting Disease (CWD)
Prevention
If CWD could spread to people, it would most likely be through eating of infected deer and elk. In a 2006-2007 CDC survey of U.S. residents, nearly 20 percent of those surveyed said they had hunted deer or elk and more than two-thirds said they had eaten venison or elk meat. However, to date, no CWD infections have been reported in people.
Hunters must consider many factors when determining whether to eat meat from deer and elk harvested from areas with CWD, including the level of risk they are willing to accept. Hunters harvesting wild deer and elk from areas with reported CWD should check state wildlife and public health guidance to see whether testing of animals is recommended or required in a given state or region. In areas where CWD is known to be present, CDC recommends that hunters strongly consider having those animals tested before eating the meat.
Tests for CWD are monitoring tools that some state wildlife officials use to look at the rates of CWD in certain animal populations. Testing may not be available in every state, and states may use these tests in different ways. A negative test result does not guarantee that an individual animal is not infected with CWD, but it does make it considerably less likely and may reduce your risk of exposure to CWD.
To be as safe as possible and decrease their potential risk of exposure to CWD, hunters should take the following steps when hunting in areas with CWD:
Do not shoot, handle or eat meat from deer and elk that look sick or are acting strangely or are found dead (road-kill). When field-dressing a deer: Wear latex or rubber gloves when dressing the animal or handling the meat. Minimize how much you handle the organs of the animal, particularly the brain or spinal cord tissues. Do not use household knives or other kitchen utensils for field dressing. Check state wildlife and public health guidance to see whether testing of animals is recommended or required. Recommendations vary by state, but information about testing is available from many state wildlife agencies. Strongly consider having the deer or elk tested for CWD before you eat the meat. If you have your deer or elk commercially processed, consider asking that your animal be processed individually to avoid mixing meat from multiple animals. If your animal tests positive for CWD, do not eat meat from that animal. The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service regulates commercially farmed deer and elk. The agency operates a national CWD herd certification program. As part of the voluntary program, states and individual herd owners agree to meet requirements meant to decrease the risk of CWD in their herds. Privately owned herds that do not participate in the herd certification program may be at increased risk for CWD.
Page last reviewed: August 17, 2017 Page last updated: August 17, 2017 Content source: Centers for Disease Control and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of High-Consequence Pathogens and Pathology (DHCPP)
> However, to date, no CWD infections have been reported in people.
key word here is 'reported'. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can't, and it's as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it's being misdiagnosed as sporadic CJD. ...terry
LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$
*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***
Molecular Barriers to Zoonotic Transmission of Prions
*** chronic wasting disease, there was no absolute barrier to conversion of the human prion protein.
*** Furthermore, the form of human PrPres produced in this in vitro assay when seeded with CWD, resembles that found in the most common human prion disease, namely sCJD of the MM1 subtype.
TUESDAY, SEPTEMBER 12, 2017
CDC Now Recommends Strongly consider having the deer or elk tested for CWD before you eat the meat
Subject: Prion 2017 Conference Abstracts CWD
2017 PRION CONFERENCE
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress
Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1
University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen
This is a progress report of a project which started in 2009. 21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves.
Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice.
At present, a total of 10 animals are sacrificed and read-outs are ongoing. Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10 years. Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation.
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS
Subject: PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS VIDEO
PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS
*** PRION 2017 CONFERENCE VIDEO
TUESDAY, JUNE 13, 2017
PRION 2017 CONFERENCE ABSTRACT
First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress
TUESDAY, JULY 04, 2017
*** PRION 2017 CONFERENCE ABSTRACTS ON CHRONIC WASTING DISEASE CWD TSE PRION ***
TUESDAY, JUNE 13, 2017
PRION 2017 CONFERENCE ABSTRACT Chronic Wasting Disease in European moose is associated with PrPSc features different from North American CWD
Wednesday, May 24, 2017
PRION2017 CONFERENCE VIDEO UPDATE 23 – 26 May 2017 Edinburgh UPDATE 1
SATURDAY, JULY 29, 2017
Risk Advisory Opinion: Potential Human Health Risks from Chronic Wasting Disease CFIA, PHAC, HC (HPFB and FNIHB), INAC, Parks Canada, ECCC and AAFC
SUNDAY, AUGUST 06, 2017
USA Chronic Wasting Disease CWD TSE Prion Emergency Response Plan Singeltary et al
TUESDAY, MARCH 28, 2017
*** Passage of scrapie to deer results in a new phenotype upon return passage to sheep ***
URINE
SUNDAY, JULY 16, 2017
*** Temporal patterns of chronic wasting disease prion excretion in three cervid species ***
TITLE: PATHOLOGICAL FEATURES OF CHRONIC WASTING DISEASE IN REINDEER AND DEMONSTRATION OF HORIZONTAL TRANSMISSION
*** DECEMBER 2016 CDC EMERGING INFECTIOUS DISEASE JOURNAL CWD HORIZONTAL TRANSMISSION
*** INFECTIOUS AGENT OF SHEEP SCRAPIE MAY PERSIST IN THE ENVIRONMENT FOR AT LEAST 16 YEARS ***
GUDMUNDUR GEORGSSON1, SIGURDUR SIGURDARSON2 AND PAUL BROWN3
the tse prion aka mad cow type disease is not your normal pathogen.
The TSE prion disease survives ashing to 600 degrees celsius, that’s around 1112 degrees farenheit.
you cannot cook the TSE prion disease out of meat.
you can take the ash and mix it with saline and inject that ash into a mouse, and the mouse will go down with TSE.
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production as well.
the TSE prion agent also survives Simulated Wastewater Treatment Processes.
IN fact, you should also know that the TSE Prion agent will survive in the environment for years, if not decades.
you can bury it and it will not go away.
The TSE agent is capable of infected your water table i.e. Detection of protease-resistant cervid prion protein in water from a CWD-endemic area.
it’s not your ordinary pathogen you can just cook it out and be done with.
that’s what’s so worrisome about Iatrogenic mode of transmission, a simple autoclave will not kill this TSE prion agent.
1: J Neurol Neurosurg Psychiatry 1994 Jun;57(6):757-8
Transmission of Creutzfeldt-Jakob disease to a chimpanzee by electrodes contaminated during neurosurgery.
Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC.
Laboratory of Central Nervous System Studies, National Institute of
Neurological Disorders and Stroke, National Institutes of Health,
Bethesda, MD 20892.
Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.
PMID: 8006664 [PubMed - indexed for MEDLINE]
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production
Detection of protease-resistant cervid prion protein in water from a CWD-endemic area
A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing
Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals
PPo4-4:
Survival and Limited Spread of TSE Infectivity after Burial
Using in vitro prion replication for high sensitive detection of prions and prionlike proteins and for understanding mechanisms of transmission.
Claudio Soto Mitchell Center for Alzheimer's diseases and related Brain disorders, Department of Neurology, University of Texas Medical School at Houston.
***Recently, we have been using PMCA to study the role of environmental prion contamination on the horizontal spreading of TSEs. These experiments have focused on the study of the interaction of prions with plants and environmentally relevant surfaces. Our results show that plants (both leaves and roots) bind tightly to prions present in brain extracts and excreta (urine and feces) and retain even small quantities of PrPSc for long periods of time. Strikingly, ingestion of prioncontaminated leaves and roots produced disease with a 100% attack rate and an incubation period not substantially longer than feeding animals directly with scrapie brain homogenate. Furthermore, plants can uptake prions from contaminated soil and transport them to different parts of the plant tissue (stem and leaves). Similarly, prions bind tightly to a variety of environmentally relevant surfaces, including stones, wood, metals, plastic, glass, cement, etc. Prion contaminated surfaces efficiently transmit prion disease when these materials were directly injected into the brain of animals and strikingly when the contaminated surfaces were just placed in the animal cage. These findings demonstrate that environmental materials can efficiently bind infectious prions and act as carriers of infectivity, suggesting that they may play an important role in the horizontal transmission of the disease.
========================
Since its invention 13 years ago, PMCA has helped to answer fundamental questions of prion propagation and has broad applications in research areas including the food industry, blood bank safety and human and veterinary disease diagnosis.
In conclusion, the results in the current study indicate that removal of furniture that had been in contact with scrapie-infected animals should be recommended, particularly since cleaning and decontamination may not effectively remove scrapie infectivity (31), even though infectivity declines considerably if the pasture and the field furniture have not been in contact with scrapie-infected sheep for several months. As sPMCA failed to detect PrPSc in furniture that was subjected to weathering, even though exposure led to infection in sheep, this method may not always be reliable in predicting the risk of scrapie infection through environmental contamination. These results suggest that the VRQ/VRQ sheep model may be more sensitive than sPMCA for the detection of environmentally associated scrapie, and suggest that extremely low levels of scrapie contamination are able to cause infection in susceptible sheep genotypes.
Keywords: classical scrapie, prion, transmissible spongiform encephalopathy, sheep, field furniture, reservoir, serial protein misfolding cyclic amplification
Wednesday, December 16, 2015
*** Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission ***
*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years ***
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
with CWD TSE Prions, I am not sure there is any absolute yet, other than what we know with transmission studies, and we know tse prion kill, and tse prion are bad. science shows to date, that indeed soil, dirt, some better than others, can act as a carrier. same with objects, farm furniture. take it with how ever many grains of salt you wish, or not. if load factor plays a role in the end formula, then everything should be on the table, in my opinion...tss
Oral Transmissibility of Prion Disease Is Enhanced by Binding to Soil Particles
Author Summary
Transmissible spongiform encephalopathies (TSEs) are a group of incurable neurological diseases likely caused by a misfolded form of the prion protein. TSEs include scrapie in sheep, bovine spongiform encephalopathy (‘‘mad cow’’ disease) in cattle, chronic wasting disease in deer and elk, and Creutzfeldt-Jakob disease in humans. Scrapie and chronic wasting disease are unique among TSEs because they can be transmitted between animals, and the disease agents appear to persist in environments previously inhabited by infected animals. Soil has been hypothesized to act as a reservoir of infectivity and to bind the infectious agent. In the current study, we orally dosed experimental animals with a common clay mineral, montmorillonite, or whole soils laden with infectious prions, and compared the transmissibility to unbound agent. We found that prions bound to montmorillonite and whole soils remained orally infectious, and, in most cases, increased the oral transmission of disease compared to the unbound agent. The results presented in this study suggest that soil may contribute to environmental spread of TSEs by increasing the transmissibility of small amounts of infectious agent in the environment.
tse prion soil
Wednesday, December 16, 2015
Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission
The sources of dust borne prions are unknown but it seems reasonable to assume that faecal, urine, skin, parturient material and saliva-derived prions may contribute to this mobile environmental reservoir of infectivity. This work highlights a possible transmission route for scrapie within the farm environment, and this is likely to be paralleled in CWD which shows strong similarities with scrapie in terms of prion dissemination and disease transmission. The data indicate that the presence of scrapie prions in dust is likely to make the control of these diseases a considerable challenge.
>>>Particle-associated PrPTSE molecules may migrate from locations of deposition via transport processes affecting soil particles, including entrainment in and movement with air and overland flow. <<<
Fate of Prions in Soil: A Review
Christen B. Smith, Clarissa J. Booth, and Joel A. Pedersen*
Several reports have shown that prions can persist in soil for several years. Significant interest remains in developing methods that could be applied to degrade PrPTSE in naturally contaminated soils. Preliminary research suggests that serine proteases and the microbial consortia in stimulated soils and compost may partially degrade PrPTSE. Transition metal oxides in soil (viz. manganese oxide) may also mediate prion inactivation. Overall, the effect of prion attachment to soil particles on its persistence in the environment is not well understood, and additional study is needed to determine its implications on the environmental transmission of scrapie and CWD.
P.161: Prion soil binding may explain efficient horizontal CWD transmission
Conclusion. Silty clay loam exhibits highly efficient prion binding, inferring a durable environmental reservoir, and an efficient mechanism for indirect horizontal CWD transmission.
>>>Another alternative would be an absolute prohibition on the movement of deer within the state for any purpose. While this alternative would significantly reduce the potential spread of CWD, it would also have the simultaneous effect of preventing landowners and land managers from implementing popular management strategies involving the movement of deer, and would deprive deer breeders of the ability to engage in the business of buying and selling breeder deer. Therefore, this alternative was rejected because the department determined that it placed an avoidable burden on the regulated community.<<<
Wednesday, December 16, 2015
Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission
Timm Konold1*, Stephen A. C. Hawkins2, Lisa C. Thurston3, Ben C. Maddison4, Kevin C. Gough5, Anthony Duarte1 and Hugh A. Simmons1
1 Animal Sciences Unit, Animal and Plant Health Agency Weybridge, Addlestone, UK, 2 Pathology Department, Animal and Plant Health Agency Weybridge, Addlestone, UK, 3 Surveillance and Laboratory Services, Animal and Plant Health Agency Penrith, Penrith, UK, 4 ADAS UK, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, UK, 5 School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, UK
Classical scrapie is an environmentally transmissible prion disease of sheep and goats. Prions can persist and remain potentially infectious in the environment for many years and thus pose a risk of infecting animals after re-stocking. In vitro studies using serial protein misfolding cyclic amplification (sPMCA) have suggested that objects on a scrapie affected sheep farm could contribute to disease transmission. This in vivo study aimed to determine the role of field furniture (water troughs, feeding troughs, fencing, and other objects that sheep may rub against) used by a scrapie-infected sheep flock as a vector for disease transmission to scrapie-free lambs with the prion protein genotype VRQ/VRQ, which is associated with high susceptibility to classical scrapie. When the field furniture was placed in clean accommodation, sheep became infected when exposed to either a water trough (four out of five) or to objects used for rubbing (four out of seven). This field furniture had been used by the scrapie-infected flock 8 weeks earlier and had previously been shown to harbor scrapie prions by sPMCA. Sheep also became infected (20 out of 23) through exposure to contaminated field furniture placed within pasture not used by scrapie-infected sheep for 40 months, even though swabs from this furniture tested negative by PMCA. This infection rate decreased (1 out of 12) on the same paddock after replacement with clean field furniture. Twelve grazing sheep exposed to field furniture not in contact with scrapie-infected sheep for 18 months remained scrapie free. The findings of this study highlight the role of field furniture used by scrapie-infected sheep to act as a reservoir for disease re-introduction although infectivity declines considerably if the field furniture has not been in contact with scrapie-infected sheep for several months. PMCA may not be as sensitive as VRQ/VRQ sheep to test for environmental contamination.
snip...
Discussion
Classical scrapie is an environmentally transmissible disease because it has been reported in naïve, supposedly previously unexposed sheep placed in pastures formerly occupied by scrapie-infected sheep (4, 19, 20). Although the vector for disease transmission is not known, soil is likely to be an important reservoir for prions (2) where – based on studies in rodents – prions can adhere to minerals as a biologically active form (21) and remain infectious for more than 2 years (22). Similarly, chronic wasting disease (CWD) has re-occurred in mule deer housed in paddocks used by infected deer 2 years earlier, which was assumed to be through foraging and soil consumption (23).
Our study suggested that the risk of acquiring scrapie infection was greater through exposure to contaminated wooden, plastic, and metal surfaces via water or food troughs, fencing, and hurdles than through grazing. Drinking from a water trough used by the scrapie flock was sufficient to cause infection in sheep in a clean building. Exposure to fences and other objects used for rubbing also led to infection, which supported the hypothesis that skin may be a vector for disease transmission (9). The risk of these objects to cause infection was further demonstrated when 87% of 23 sheep presented with PrPSc in lymphoid tissue after grazing on one of the paddocks, which contained metal hurdles, a metal lamb creep and a water trough in contact with the scrapie flock up to 8 weeks earlier, whereas no infection had been demonstrated previously in sheep grazing on this paddock, when equipped with new fencing and field furniture. When the contaminated furniture and fencing were removed, the infection rate dropped significantly to 8% of 12 sheep, with soil of the paddock as the most likely source of infection caused by shedding of prions from the scrapie-infected sheep in this paddock up to a week earlier.
This study also indicated that the level of contamination of field furniture sufficient to cause infection was dependent on two factors: stage of incubation period and time of last use by scrapie-infected sheep. Drinking from a water trough that had been used by scrapie sheep in the predominantly pre-clinical phase did not appear to cause infection, whereas infection was shown in sheep drinking from the water trough used by scrapie sheep in the later stage of the disease. It is possible that contamination occurred through shedding of prions in saliva, which may have contaminated the surface of the water trough and subsequently the water when it was refilled. Contamination appeared to be sufficient to cause infection only if the trough was in contact with sheep that included clinical cases. Indeed, there is an increased risk of bodily fluid infectivity with disease progression in scrapie (24) and CWD (25) based on PrPSc detection by sPMCA. Although ultraviolet light and heat under natural conditions do not inactivate prions (26), furniture in contact with the scrapie flock, which was assumed to be sufficiently contaminated to cause infection, did not act as vector for disease if not used for 18 months, which suggest that the weathering process alone was sufficient to inactivate prions.
PrPSc detection by sPMCA is increasingly used as a surrogate for infectivity measurements by bioassay in sheep or mice. In this reported study, however, the levels of PrPSc present in the environment were below the limit of detection of the sPMCA method, yet were still sufficient to cause infection of in-contact animals. In the present study, the outdoor objects were removed from the infected flock 8 weeks prior to sampling and were positive by sPMCA at very low levels (2 out of 37 reactions). As this sPMCA assay also yielded 2 positive reactions out of 139 in samples from the scrapie-free farm, the sPMCA assay could not detect PrPSc on any of the objects above the background of the assay. False positive reactions with sPMCA at a low frequency associated with de novo formation of infectious prions have been reported (27, 28). This is in contrast to our previous study where we demonstrated that outdoor objects that had been in contact with the scrapie-infected flock up to 20 days prior to sampling harbored PrPSc that was detectable by sPMCA analysis [4 out of 15 reactions (12)] and was significantly more positive by the assay compared to analogous samples from the scrapie-free farm. This discrepancy could be due to the use of a different sPMCA substrate between the studies that may alter the efficiency of amplification of the environmental PrPSc. In addition, the present study had a longer timeframe between the objects being in contact with the infected flock and sampling, which may affect the levels of extractable PrPSc. Alternatively, there may be potentially patchy contamination of this furniture with PrPSc, which may have been missed by swabbing. The failure of sPMCA to detect CWD-associated PrP in saliva from clinically affected deer despite confirmation of infectivity in saliva-inoculated transgenic mice was associated with as yet unidentified inhibitors in saliva (29), and it is possible that the sensitivity of sPMCA is affected by other substances in the tested material. In addition, sampling of amplifiable PrPSc and subsequent detection by sPMCA may be more difficult from furniture exposed to weather, which is supported by the observation that PrPSc was detected by sPMCA more frequently in indoor than outdoor furniture (12). A recent experimental study has demonstrated that repeated cycles of drying and wetting of prion-contaminated soil, equivalent to what is expected under natural weathering conditions, could reduce PMCA amplification efficiency and extend the incubation period in hamsters inoculated with soil samples (30). This seems to apply also to this study even though the reduction in infectivity was more dramatic in the sPMCA assays than in the sheep model. Sheep were not kept until clinical end-point, which would have enabled us to compare incubation periods, but the lack of infection in sheep exposed to furniture that had not been in contact with scrapie sheep for a longer time period supports the hypothesis that prion degradation and subsequent loss of infectivity occurs even under natural conditions.
In conclusion, the results in the current study indicate that removal of furniture that had been in contact with scrapie-infected animals should be recommended, particularly since cleaning and decontamination may not effectively remove scrapie infectivity (31), even though infectivity declines considerably if the pasture and the field furniture have not been in contact with scrapie-infected sheep for several months. As sPMCA failed to detect PrPSc in furniture that was subjected to weathering, even though exposure led to infection in sheep, this method may not always be reliable in predicting the risk of scrapie infection through environmental contamination. These results suggest that the VRQ/VRQ sheep model may be more sensitive than sPMCA for the detection of environmentally associated scrapie, and suggest that extremely low levels of scrapie contamination are able to cause infection in susceptible sheep genotypes.
Keywords: classical scrapie, prion, transmissible spongiform encephalopathy, sheep, field furniture, reservoir, serial protein misfolding cyclic amplification
Wednesday, December 16, 2015
*** Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission ***
*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years ***
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
MONDAY, JUNE 12, 2017
Rethinking Major grain organizations opposition to CFIA's control zone approach to Chronic Wasting CWD TSE Prion Mad Deer Type Disease 2017?
WEDNESDAY, MAY 17, 2017
*** Chronic Wasting Disease CWD TSE Prion aka Mad Deer Disease and the Real Estate Market Land Values ***
*** 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.
THURSDAY, AUGUST 03, 2017
Wisconsin CWD Showing Up in Northern Wisconsin Deer Farms
WISCONSIN CWD CASES OUT OF CONTROL
Monday, May 16, 2016
Governor Walker Announces Several Initiatives to Combat Chronic Wasting Disease in Wisconsin
Sunday, May 08, 2016
WISCONSIN CHRONIC WASTING DISEASE CWD TSE PRION SPIRALING FURTHER INTO THE ABYSS UPDATE
MONDAY, MARCH 20, 2017
Wisconsin CWD TSE Prion Annual Roundup 441 positive
Wednesday, March 16, 2016
Wisconsin CWD sample survey 2015 confirms 290 cases of Chronic Wasting Disease TSE Prion
Wednesday, February 10, 2016
*** Wisconsin Two deer that escaped farm had chronic wasting disease CWD ***
Monday, May 16, 2016
Governor Walker Announces Several Initiatives to Combat Chronic Wasting Disease in Wisconsin
CHRONIC WASTING DISEASE CWD WISCONSIN Almond Deer (Buckhorn Flats) Farm Update DECEMBER 2011
The CWD infection rate was nearly 80%, the highest ever in a North American captive herd.
RECOMMENDATION: That the Board approve the purchase of 80 acres of land for $465,000 for the Statewide Wildlife Habitat Program in Portage County and approve the restrictions on public use of the site.
SUMMARY:
J Vet Diagn Invest 20:698–703 (2008)
Chronic wasting disease in a Wisconsin white-tailed deer farm
Delwyn P. Keane,1 Daniel J. Barr, Philip N. Bochsler, S. Mark Hall, Thomas Gidlewski, Katherine I. O’Rourke, Terry R. Spraker, Michael D. Samuel
Abstract.
In September 2002, chronic wasting disease (CWD), a prion disorder of captive and wild cervids, was diagnosed in a white-tailed deer (Odocoileus virginianus) from a captive farm in Wisconsin. The facility was subsequently quarantined, and in January 2006 the remaining 76 deer were depopulated. Sixty animals (79%) were found to be positive by immunohistochemical staining for the abnormal prion protein (PrPCWD) in at least one tissue; the prevalence of positive staining was high even in young deer. Although none of the deer displayed clinical signs suggestive of CWD at depopulation, 49 deer had considerable accumulation of the abnormal prion in the medulla at the level of the obex. Extraneural accumulation of the abnormal protein was observed in 59 deer, with accumulation in the retropharyngeal lymph node in 58 of 59 (98%), in the tonsil in 56 of 59 (95%), and in the rectal mucosal lymphoid tissue in 48 of 58 (83%). The retina was positive in 4 deer, all with marked accumulation of prion in the obex. One deer was considered positive for PrPCWD in the brain but not in the extraneural tissue, a novel observation in white-tailed deer. The infection rate in captive deer was 20- fold higher than in wild deer. Although weakly related to infection rates in extraneural tissues, prion genotype was strongly linked to progression of prion accumulation in the obex. Antemortem testing by biopsy of recto– anal mucosal-associated lymphoid tissue (or other peripheral lymphoid tissue) may be a useful adjunct to tonsil biopsy for surveillance in captive herds at risk for CWD infection.
Key words: Cervids; chronic wasting disease; prion; transmissible spongiform encephalopathy.
State pays farmer $298,000 for infected deer herd
Jan. 16, 2016 8:05 p.m.
The State of Wisconsin paid nearly $300,000 to the Eau Claire County farmer whose deer herd was depopulated after it was found to be infected with chronic wasting disease.
Rick Vojtik, owner of Fairchild Whitetails in Fairchild, received an indemnity payment of $298,770 for 228 white-tailed deer killed on his farm, according to officials with the Department of Agriculture, Trade and Consumer Protection.
The money was taken from the agency's general program revenue funded by Wisconsin taxpayers.
CHRONIC WASTING DISEASE CWD WISCONSIN Almond Deer (Buckhorn Flats) Farm Update DECEMBER 2011
The CWD infection rate was nearly 80%, the highest ever in a North American captive herd.
RECOMMENDATION: That the Board approve the purchase of 80 acres of land for $465,000 for the Statewide Wildlife Habitat Program in Portage County and approve the restrictions on public use of the site.
SUMMARY:
For Immediate Release Thursday, October 2, 2014
Dustin Vande Hoef 515/281-3375 or 515/326-1616 (cell) or Dustin.VandeHoef@IowaAgriculture.gov
*** TEST RESULTS FROM CAPTIVE DEER HERD WITH CHRONIC WASTING DISEASE RELEASED 79.8 percent of the deer tested positive for the disease
DES MOINES – The Iowa Department of Agriculture and Land Stewardship today announced that the test results from the depopulation of a quarantined captive deer herd in north-central Iowa showed that 284 of the 356 deer, or 79.8% of the herd, tested positive for Chronic Wasting Disease (CWD).
*** see history of this CWD blunder here ;
On June 5, 2013, DNR conducted a fence inspection, after gaining approval from surrounding landowners, and confirmed that the fenced had been cut or removed in at least four separate locations; that the fence had degraded and was failing to maintain the enclosure around the Quarantined Premises in at least one area; that at least three gates had been opened;and that deer tracks were visible in and around one of the open areas in the sand on both sides of the fence, evidencing movement of deer into the Quarantined Premises.
The overall incidence of clinical CWD in white-tailed deer was 82%
Species (cohort) CWD (cases/total) Incidence (%) Age at CWD death (mo)
MONDAY, SEPTEMBER 25, 2017
WEDNESDAY, SEPTEMBER 27, 2017
TEXAS, TPWD, WIN CWD COURT CASE AGAINST DEER BREEDERS CAUSE NO. D-1-GN-15-004391
THURSDAY, SEPTEMBER 21, 2017
TEXAS TPWD CWD mandatory check stations for Chronic Wasting Disease in the South Central, Panhandle, and Trans-Pecos areas
MONDAY, AUGUST 14, 2017
*** Texas Chronic Wasting Disease CWD TSE Prion History
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
11:07 AM
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