Saturday, April 9, 2016

The Norwegian Veterinary Institute (NVI, 2016) has reported a case of prion disease Cervid Spongiform Encephalopathy detected in free ranging wild reindeer (Rangifer tarandus tarandus)

Department for Environment, Food and Rural Affairs

 

Animal and Plant Health Agency

 

Veterinary & Science Policy Advice Team - International Disease Monitoring

 

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Preliminary Outbreak Assessment

 

Cervid Spongiform Encephalopathy in Norway

 

7th April 2016 Ref: VITT/1200 Cervid disease in Norway

 

Disease Report

 

The Norwegian Veterinary Institute (NVI, 2016) has reported a case of prion disease detected in free ranging wild reindeer (Rangifer tarandus tarandus), one of a southern population of wild reindeer in the Nordfjella region of Norway; see map; http://www.vetinst.no/eng/Highlights/The-first-detection-of-Chronic-Wasting-Disease-CWD-in-Europe). The (found dead) adult doe showed signs of below average body condition and was tested as part of the national surveillance programme for CWD in wild ungulates. Prion disease was confirmed in mid-March by both biochemical and immunohistochemical tests. Samples are being sent to the OIE reference laboratory (Canada) before confirmation as Chronic Wasting Disease can be made. If confirmed, this would be the first case of Chronic Wasting Disease detected in Europe. Initial experimental research, suggests that human susceptibility to CWD is low and there may be a robust species barrier preventing CWD transmission to humans (Sigurdson, 2008). Norway has put in place additional surveillance.

 

Situation Assessment

 

CWD is found in 21 States in the USA as well as the provinces of Alberta and Saskatchewan in Canada (UGS, 2016). It is a slow moving, contagious prion disease which only affects several species of captive and wild cervid, commonly the White tailed deer, Odocoileus virginianus), elk (Cervus elaphus nelsoni) and moose (Alces alces shirasi). This would be the first detection in a naturally-infected reindeer or the related (American) subspecies, caribou.

 

Current range of CWD in North America (USGS, 2016)

 

Department for Environment, Food and Rural Affairs Animal and Plant Health Agency Veterinary & Science Policy Advice Team - International Disease Monitoring

 

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There are four native cervid species in Norway: moose (Alces alces), red deer (Cervus elaphus), roe deer (Capreolus capreolus) and reindeer (Rangifer tarandus). A large number of free ranging populations graze in areas where another, TSE, scrapie, has been detected (Sviland et al. 2015). Hunting is a popular sport, with over 5% of Norwegians holding hunting licenses to hunt all four native species and around 100,000 animals are hunted a year (Norwegian Scientific Committee for Food Safety, 2013).

 

Reindeer, where farmed or herded in Norway, come under the jurisdiction of the Norwegian Reindeer Herding Act, 2007. Almost 40% of the Nordic Countries is a reindeer herding area with between 240,000 and 250,000 animals, located mostly in the North, however herding in Norway is restricted to those with the right to have a reindeer earmark (Sámi people or first / second generation descendants of Sámi), except in the Norwegian Concession Area, where both Sámi and non-Sámi people are engaged in herding (Nordregio, 2016). Wild reindeer live in dispersed populations in separate high mountain areas in southern Norway. Official figures for hunted animals in 2013 put the number at 7,900, more than in previous years (Sviland et al., 2015; Norwegian Scientific Committee for Food Safety, 2013). Reindeer are an important species for this region, with special protected status.

 

Map of reindeer herding areas in Nordic Countries (Nordregio, 2016)

 

Norway carries out annual surveillance of reindeer for CWD (Sviland et al., 2015). Fallen stock of wild cervids over the age of 18 months and captive deer are tested. In 2014, very few animals (10) were tested as part of the surveillance and all tested negative; none of these were reindeer. In 2013, 10 animals also tested negative and in 2012, 21 animals tested negative.

 

Reindeer are not native to the UK and there are only a limited number of sites where reindeer are kept. According to the British Deer Society (2016), there are four sites in GB where reindeer may be found: one in Gloucestershire; one in Fife and two in Inverness-shire. There is understood to be a semi-wild reindeer herd in the Cairngorms, Scotland. According to TRACES, the EU electronic trade notification system, since 2013 there have been 27 consignments of 595 reindeer from the Nordic Countries, but only 2 from Norway,

 

Department for Environment, Food and Rural Affairs Animal and Plant Health Agency Veterinary & Science Policy Advice Team - International Disease Monitoring

 

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in 2013 and 2015, totalling 28 reindeer. The UK has several species of native deer which may be susceptible (eg red deer).

 

This would be the first natural case of CWD in a reindeer. Experimental evidence from oral transmission experiments of CWD recovered from brain tissue of white tailed deer or elk demonstrated clinical disease in two of three reindeer which received inoculum from white tailed deer but in none of the three animals receiving inoculum from elk (Mitchell et al, 2012). Tissue distribution of prion protein (PrPCWD) was similar to that observed in other infected cervids, with multiple organ depositions. Therefore the presence of PrPCWD in saliva, faeces and urine, as seen with other cervids, would also be expected in the case of infected reindeer. In this small experiment, the three reindeer tested appeared not to be infected by CWD isolated from infected elk brain tissue, but there were no definitive conclusions as to whether this was due to a resistant genotype or low titre inoculum.

 

As seen with the disease status of the USA, once disease becomes established in wildlife, it is very difficult to control. Preventing contact with captive livestock or their pasture will be paramount.

 

Conclusion

 

The presence of CWD in a European population of cervids changes the risk assessment to the UK. The risk of incursion was previously considered to be very low, and when more information is available, we will re-assess. What is unknown at present is what the distribution of CWD is in deer in Scandinavia or other parts of Europe: whether it represents a wider problem in farmed reindeer, in other cervid species and other regions or if this is restricted to the wild reindeer in this region and how the disease has arisen: through contact with contaminated equipment, animal by-products from infected animals, feed or as a spontaneous mutation.

 

We have recently published an updated qualitative risk assessment on the entry pathways for CWD to GB, focussing on North America. This follows reports of imported white tailed deer urine which may be used by hunters as lures in Europe and the assessment considers the potential for such products, whether processed or not, for carrying CWD infectious agents. Other potential pathways include contaminated footwear, hunting equipment or pet food made from venison. For more information please see our qualitative risk assessments available on the gov.uk website, or see www.bds.org.uk.

 

We will report again when more information is available.

 

Authors Dr Helen Roberts Dr Paul Gale Dr Jim Hope Dr Marion Simmons Department for Environment, Food and Rural Affairs Animal and Plant Health Agency Veterinary & Science Policy Advice Team - International Disease Monitoring 4

 

References

 

British Deer Society (2016) Where to see deer http://www.bds.org.uk/index.php/advice-education/watching-deer/where-to-see-deer Accessed 06/04/2016. Mitchell GB, Sigurdson CJ, O’Rourke KI, Algire J, Harrington NP, et al. (2012) Experimental Oral Transmission of Chronic Wasting Disease to Reindeer (Rangifer tarandus tarandus). PLoS ONE 7(6): e39055. doi:10.1371/journal.pone.0039055. Nordregio (2016) Reindeer herding area in the Nordic Countries http://www.nordregio.se/Templates/NordRegio/Pages/MapPage.aspx?id=3619&epslanguage=en Accessed 06/04/2016. Norwegian Scientific Committee for Food Safety (2013) Risk assessment of lead exposure from cervid meat in Norwegian consumers and in hunting dogs. http://www.english.vkm.no/dav/bfbc0b16e9.pdf Accessed 06/04/2016. NVI (2016) The first detection of Chronic Wasting Disease (CWD) in Europe. http://www.vetinst.no/eng/Highlights/The-first-detection-of-Chronic-Wasting-Disease-CWD-in-Europe Accessed 06/04/2016. Sigurdson, C.J. (2008) A prion disease of cervids: Chronic wasting disease. Veterinary Research, 39, 41. Svilan, S., Vikoren, T., Tarpai, A. & Benestad, S.L. (2015) The surveillance programme for Chronic Wasting Disease (CWD) in Norway, 2014. Surveillance programmes for terrestrial and aquatic animals in Norway. Annual report 2014. Oslo: Norwegian Veterinary Institute 2015. © Crown copyright 2016 You may re-use this information (excluding logos) free of charge in any format or medium, under the terms of the Open Government Licence v.2. To view this licence visit www.nationalarchives.gov.uk/doc/open-government-licence/version/2/ or email PSI@nationalarchives.gsi.gov.uk This publication is available at https://www.gov.uk/government/collections/animal-diseases-international-monitoring Any enquiries regarding this publication should be sent to us at helen.roberts@apha.gsi.gov.uk

 




Thursday, January 29, 2015

Atypical H-TYPE BSE Case Confirmed in Norway




Thursday, April 07, 2016

 

What is the risk of chronic wasting disease being introduced into Great Britain? An updated Qualitative Risk Assessment March 2016

 

Sheep and cattle may be exposed to CWD via common grazing areas with affected deer but so far, appear to be poorly susceptible to mule deer CWD (Sigurdson, 2008).

 

***In contrast, cattle are highly susceptible to white-tailed deer CWD and mule deer CWD in experimental conditions but no natural CWD infections in cattle have been reported (Sigurdson, 2008; Hamir et al., 2006). It is not known how susceptible humans are to CWD but given that the prion can be present in muscle, it is likely that humans have been exposed to the agent via consumption of venison (Sigurdson, 2008). Initial experimental research, however, suggests that human susceptibility to CWD is low and there may be a robust species barrier for CWD transmission to humans (Sigurdson, 2008). It is apparent, though, that CWD is affecting wild and farmed cervid populations in endemic areas with some deer populations decreasing as a result.

 

snip...

 

For the purpose of the qualitative risk assessment developed here it is necessary to estimate the probability that a 30-ml bottle of lure contains urine from an infected deer. This requires an estimate of the proportion of deer herds in the USA which are infected with CWD together with the within herd prevalence.

 

The distribution map of CWD in US shows it is present mainly in central states (Figure 1). However, Virginia in the east of the country has recorded seven recent cases of CWD (Anon 2015a). Some US manufacturers claim to take steps to prevent urine being taken from infected animals eg by sourcing from farms where the deer are randomly tested for CWD (Anon 2015a). However, if disease is already present and testing is not carried out regularly, captive populations are not necessarily disease free (Strausser 2014). Urine-based deer lures have been known to be collected from domestic white-tailed deer herds and therefore there is a recognised risk. This is reflected by 6 US States which have

 

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banned the use of natural deer urine for lures, as the deer urine may be sourced from CWD-endemic areas in the USA as well as from areas free of CWD. For example, the US State of Virginia is banning the use of urine-based deer lures on July 2015 and Vermont from 2016 due to the risk of spread of CWD. Alaska banned their use in 2012 (Anon 2015a). Pennsylvania Game Commission has banned urine-based deer lures and acknowledged that there is no way to detect their use (Strausser 2014). On the basis of unpublished data (J. Manson, Pers. Comm.) it appears that up to 50% of deer herds can be infected with 80-90% of animals infected within some herds.

 

*** It is therefore assumed that probability that a 30-ml bottle of deer urine lure imported from the USA is sources from an infected deer is medium.

 

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 cannot be determined, however, as it is not specified in TRACES. It may constitute a small percentage of the very low tonnage of non-fish origin processed animal proteins that were imported from US into GB.

 

*** Overall, therefore, it is considered there is a greater than negligible risk that (non-ruminant) 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...

 


 

Summary and MORE HERE ;

 

What is the risk of chronic wasting disease being introduced into Great Britain? An updated Qualitative Risk Assessment March 2016

 


 

I strenuously once again urge the FDA and its industry constituents, to make it MANDATORY that all ruminant feed be banned to all ruminants, and this should include all cervids, as well as non-ruminants such as cats and dogs as well, as soon as possible for the following reasons...

 

31 Jan 2015 at 20:14 GMT

 

*** Ruminant feed ban for cervids in the United States? ***

 

31 Jan 2015 at 20:14 GMT

 

see Singeltary comment ;

 


 

Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission

 

Greetings again FDA and Mr. Pritchett et al,

 

I would kindly like to comment on ;

 

Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission

 

#158

 

Guidance for Industry

 

Use of Material from Deer and Elk in Animal Feed

 

This version of the guidance replaces the version made available September15, 2003.

 

This document has been revised to update the docket number, contact information, and standard disclosures. Submit comments on this guidance at any time.

 

Submit electronic comments to http://www.regulations.gov. Submit written comments to the Division of Dockets Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, Rm. 1061, Rockville, MD 20852. All comments should be identified with the Docket No. FDA-2003-D-0432 (formerly 03D-0186).

 

For further information regarding this guidance, contact Burt Pritchett, Center for Veterinary Medicine (HFV-222), Food and Drug Administration, 7519 Standish Place, Rockville, MD 20855, 240-402-6276, E-mail: burt.pritchett@fda.hhs.gov.

 

Additional copies of this guidance document may be requested from the Policy and Regulations Staff (HFV-6), Center for Veterinary Medicine, Food and Drug Administration, 7519 Standish Place, Rockville, MD 20855, and may be viewed on the Internet at either http://www.fda.gov/AnimalVeterinary/default.htm or http://www.regulations.gov.

 

U.S. Department of Health and Human Services Food and Drug Administration Center for Veterinary Medicine March 2016

 

Contains Nonbinding Recommendations

 

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Guidance for Industry Use of Material from Deer and Elk in Animal Feed

 

This guidance represents the current thinking of the Food and Drug Administration (FDA or Agency) on this topic. It does not establish any rights for any person and is not binding on FDA or the public. You can use an alternative approach if it satisfies the requirements of the applicable statutes and regulations. To discuss an alternative approach, contact the FDA office responsible for this guidance as listed on the title page.

 

I. Introduction

 

Under FDA’s BSE feed regulation (21 CFR 589.2000) most material from deer and elk is prohibited for use in feed for ruminant animals. This guidance document describes FDA’s recommendations regarding the use in all animal feed of all material from deer and elk that are positive for Chronic Wasting Disease (CWD) or are considered at high risk for CWD. The potential risks from CWD to humans or non-cervid animals such as poultry and swine are not well understood. However, because of recent recognition that CWD is spreading rapidly in white-tailed deer, and because CWD’s route of transmission is poorly understood, FDA is making recommendations regarding the use in animal feed of rendered materials from deer and elk that are CWD-positive or that are at high risk for CWD.

 

In general, FDA’s guidance documents do not establish legally enforceable responsibilities. Instead, guidances describe the Agency’s current thinking on a topic and should be viewed only as recommendations, unless specific regulatory or statutory requirements are cited. The use of the word should in Agency guidances means that something is suggested or recommended, but not required.

 

II. Background

 

CWD is a neurological (brain) disease of farmed and wild deer and elk that belong in the animal family cervidae (cervids). Only deer and elk are known to be susceptible to CWD by natural transmission. The disease has been found in farmed and wild mule deer, white-tailed deer, North American elk, and in farmed black-tailed deer. CWD belongs to a family of animal and human diseases called transmissible spongiform encephalopathies (TSEs). These include bovine spongiform encephalopathy (BSE or “mad cow” disease) in cattle; scrapie in sheep and goats; and classical and variant Creutzfeldt-Jakob diseases (CJD and vCJD) in humans. There is no known treatment for these diseases, and there is no vaccine to prevent them. In addition, although validated postmortem diagnostic tests are available, there are no validated diagnostic tests for CWD that can be used to test for the disease in live animals.

 

Contains Nonbinding Recommendations

 

III. Use in animal feed of material from CWD-positive deer and elk

 

Material from CWD-positive animals may not be used in any animal feed or feed ingredients. Pursuant to Sec. 402(a)(5) of the Federal Food, Drug, and Cosmetic Act, animal feed and feed ingredients containing material from a CWD-positive animal would be considered adulterated. FDA recommends that any such adulterated feed or feed ingredients be recalled or otherwise removed from the marketplace.

 

IV. Use in animal feed of material from deer and elk considered at high risk for CWD Deer and elk considered at high risk for CWD include: (1) animals from areas declared by State officials 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 immediately before the time of slaughter were in a captive herd that contained a CWD-positive animal.

 

FDA recommends that materials from deer and elk considered at high risk for CWD no longer be entered into the animal feed system. Under present circumstances, FDA is not recommending that feed made from deer and elk from a non-endemic area be recalled if a State later declares the area endemic for CWD or a CWD eradication zone. In addition, at this time, FDA is not recommending that feed made from deer and elk believed to be from a captive herd that contained no CWD-positive animals be recalled if that herd is subsequently found to contain a CWD-positive animal.

 

V. Use in animal feed of material from deer and elk NOT considered at high risk for CWD FDA continues to consider materials from deer and elk NOT considered at high risk for CWD to be acceptable for use in NON-RUMINANT animal feeds in accordance with current agency regulations, 21 CFR 589.2000. Deer and elk not considered at high risk include: (1) deer and elk from areas not declared by State officials to be endemic for CWD and/or to be CWD eradication zones; and (2) deer and elk that were not at some time during the 60-month period immediately before the time of slaughter in a captive herd that contained a CWD-positive animal.

 

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Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission

 

Greetings again FDA and Mr. Pritchett et al,

 

MY comments and source reference of sound science on this very important issue are as follows ;

 

Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission

 

I kindly wish to once again submit to Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed.

 

Thank you kindly for allowing me to comment again, ...and again...and again, on a topic so important, why it is ‘NON-BINDING’ is beyond me.

 

this should have been finalized and made ‘BINDING’ or MANDATORY OVER A DECADE AGO.

 

but here lay the problem, once made ‘BINDING’ or ‘MANDATORY’, it is still nothing but ink on paper.

 

we have had a mad cow feed ban in place since August 1997, and since then, literally 100s of millions of pounds BANNED MAD COW FEED has been sent out to commerce and fed out (see reference materials).

 

ENFORCEMENT OF SAID BINDING REGULATIONS HAS FAILED US TOO MANY TIMES.

 

so, in my opinion, any non-binding or voluntary regulations will not work, and to state further, ‘BINDING’ or MANDATORY regulations will not work unless enforced.

 

with that said, we know that Chronic Wasting Disease CWD TSE Prion easily transmits to other cervid through the oral route.

 

the old transmission studies of BSE TSE floored scientist once they figured out what they had, and please don’t forget about those mink that were fed 95%+ dead stock downer cow, that all came down with TME. please see ;

 

It is clear that the designing scientists must also have shared Mr Bradleys surprise at the results because all the dose levels right down to 1 gram triggered infection.

 


 

it is clear that the designing scientists must have also shared Mr Bradleys surprise at the results because all the dose levels right down to 1 gram triggered infection.

 


 

Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle

 

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

 

snip...

 

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

 


 

Friday, April 08, 2016

 

Arkansas AGFC Chronic Wasting Disease CWD TSE Prion Confirms 23 Additional Cases Total At 79 To Date

 


 


 

Saturday, April 02, 2016

 

TEXAS TAHC BREAKS IT'S SILENCE WITH TWO MORE CASES CWD CAPTIVE DEER BRINGING TOTAL TO 10 CAPTIVES REPORTED TO DATE

 


 

PRION 2015 CONFERENCE FT. COLLINS CWD RISK FACTORS TO HUMANS

 

*** LATE-BREAKING ABSTRACTS PRION 2015 CONFERENCE ***

 

O18

 

Zoonotic Potential of CWD Prions

 

Liuting Qing1, Ignazio Cali1,2, Jue Yuan1, Shenghai Huang3, Diane Kofskey1, Pierluigi Gambetti1, Wenquan Zou1, Qingzhong Kong1 1Case Western Reserve University, Cleveland, Ohio, USA, 2Second University of Naples, Naples, Italy, 3Encore Health Resources, Houston, Texas, USA

 

*** These results indicate that the CWD prion has the potential to infect human CNS and peripheral lymphoid tissues and that there might be asymptomatic human carriers of CWD infection.

 

==================

 

***These results indicate that the CWD prion has the potential to infect human CNS and peripheral lymphoid tissues and that there might be asymptomatic human carriers of CWD infection.***

 

==================

 

P.105: RT-QuIC models trans-species prion transmission

 

Kristen Davenport, Davin Henderson, Candace Mathiason, and Edward Hoover Prion Research Center; Colorado State University; Fort Collins, CO USA

 

Conversely, FSE maintained sufficient BSE characteristics to more efficiently convert bovine rPrP than feline rPrP. Additionally, human rPrP was competent for conversion by CWD and fCWD.

 

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

 

================

 

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

 

================

 


 

*** PRICE OF CWD TSE PRION POKER GOES UP 2014 ***

 

Transmissible Spongiform Encephalopathy TSE PRION update January 2, 2014

 

*** 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.

 


 


 

*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***

 


 

*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies.

 


 

now, let’s see what the authors said about this casual link, personal communications years ago. see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ???? “Our conclusion stating that we found no strong evidence of CWD transmission to humans”

 

From: TSS (216-119-163-189.ipset45.wt.net)

 

Subject: CWD aka MAD DEER/ELK TO HUMANS ???

 

Date: September 30, 2002 at 7:06 am PST

 

From: "Belay, Ermias"

 

To: Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"

 

Sent: Monday, September 30, 2002 9:22 AM

 

Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS

 

Dear Sir/Madam,

 

In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD. That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091). Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.

 

Ermias Belay, M.D. Centers for Disease Control and Prevention

 

-----Original Message-----

 

From: Sent: Sunday, September 29, 2002 10:15 AM

 

To: rr26k@nih.gov; rrace@niaid.nih.gov; ebb8@CDC.GOV

 

Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS

 

Sunday, November 10, 2002 6:26 PM ......snip........end..............TSS

 

Thursday, April 03, 2008

 

A prion disease of cervids: Chronic wasting disease 2008 1: Vet Res. 2008 Apr 3;39(4):41 A prion disease of cervids: Chronic wasting disease Sigurdson CJ.

 

snip...

 

*** twenty-seven CJD patients who regularly consumed venison were reported to the Surveillance Center***,

 

snip... full text ;

 


 

CJD is so rare in people under age 30, one case in a billion (leaving out medical mishaps), that four cases under 30 is "very high," says Colorado neurologist Bosque. "Then, if you add these other two from Wisconsin [cases in the newspaper], six cases of CJD in people associated with venison is very, very high." Only now, with Mary Riley, there are at least seven, and possibly eight, with Steve, her dining companion. "It's not critical mass that matters," however, Belay says. "One case would do it for me." The chance that two people who know each other would both contact CJD, like the two Wisconsin sportsmen, is so unlikely, experts say, it would happen only once in 140 years.

 

Given the incubation period for TSEs in humans, it may require another generation to write the final chapter on CWD in Wisconsin. "Does chronic wasting disease pass into humans? We'll be able to answer that in 2022," says Race. Meanwhile, the state has become part of an immense experiment.

 


 

I urge everyone to watch this video closely...terry

 

*** you can see video here and interview with Jeff's Mom, and scientist telling you to test everything and potential risk factors for humans ***

 


 

Envt.07:

 

Pathological Prion Protein (PrPTSE) in Skeletal Muscles of Farmed and Free Ranging White-Tailed Deer Infected with Chronic Wasting Disease

 

***The presence and seeding activity of PrPTSE in skeletal muscle from CWD-infected cervids suggests prevention of such tissue in the human diet as a precautionary measure for food safety, pending on further clarification of whether CWD may be transmissible to humans.

 


 

Prions in Skeletal Muscles of Deer with Chronic Wasting Disease Rachel C. Angers1,*, Shawn R. Browning1,*,†, Tanya S. Seward2, Christina J. Sigurdson4,‡, Michael W. Miller5, Edward A. Hoover4, Glenn C. Telling1,2,3,§ snip...

 

Abstract The emergence of chronic wasting disease (CWD) in deer and elk in an increasingly wide geographic area, as well as the interspecies transmission of bovine spongiform encephalopathy to humans in the form of variant Creutzfeldt Jakob disease, have raised concerns about the zoonotic potential of CWD. Because meat consumption is the most likely means of exposure, it is important to determine whether skeletal muscle of diseased cervids contains prion infectivity. Here bioassays in transgenic mice expressing cervid prion protein revealed the presence of infectious prions in skeletal muscles of CWD-infected deer, demonstrating that humans consuming or handling meat from CWD-infected deer are at risk to prion exposure.

 


 

***********CJD REPORT 1994 increased risk for consumption of veal and venison and lamb***********

 

CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994

 

Consumption of venison and veal was much less widespread among both cases and controls. For both of these meats there was evidence of a trend with increasing frequency of consumption being associated with increasing risk of CJD. (not nvCJD, but sporadic CJD...tss)

 

These associations were largely unchanged when attention was restricted to pairs with data obtained from relatives. ...

 

Table 9 presents the results of an analysis of these data.

 

There is STRONG evidence of an association between ‘’regular’’ veal eating and risk of CJD (p = .0.01).

 

Individuals reported to eat veal on average at least once a year appear to be at 13 TIMES THE RISK of individuals who have never eaten veal.

 

There is, however, a very wide confidence interval around this estimate. There is no strong evidence that eating veal less than once per year is associated with increased risk of CJD (p = 0.51).

 

The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).

 

There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02).

 

The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).

 

snip...

 

It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).

 

snip...

 

In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...

 

snip...

 

In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)

 

snip...see full report ;

 


 

CJD9/10022

 

October 1994

 

Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane BerksWell Coventry CV7 7BZ

 

Dear Mr Elmhirst,

 

CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT

 

Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.

 

The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.

 

The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.

 

The statistical results reqarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.

 

I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.

 


 

*** 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).***

 


 

O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations

 

Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France

 

Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases). Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.

 

*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,

 

***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),

 

***is the third potentially zoonotic PD (with BSE and L-type BSE),

 

***thus questioning the origin of human sporadic cases. We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.

 

===============

 

***thus questioning the origin of human sporadic cases***

 

===============

 

***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.

 

==============

 


 

Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES

 

Title: Transmission of scrapie prions to primate after an extended silent incubation period

 

Authors

 

item Comoy, Emmanuel - item Mikol, Jacqueline - item Luccantoni-Freire, Sophie - item Correia, Evelyne - item Lescoutra-Etchegaray, Nathalie - item Durand, Valérie - item Dehen, Capucine - item Andreoletti, Olivier - item Casalone, Cristina - item Richt, Juergen item Greenlee, Justin item Baron, Thierry - item Benestad, Sylvie - item Hills, Bob - item Brown, Paul - item Deslys, Jean-Philippe -

 

Submitted to: Scientific Reports Publication Type: Peer Reviewed Journal Publication Acceptance Date: May 28, 2015 Publication Date: June 30, 2015 Citation: Comoy, E.E., Mikol, J., Luccantoni-Freire, S., Correia, E., Lescoutra-Etchegaray, N., Durand, V., Dehen, C., Andreoletti, O., Casalone, C., Richt, J.A., Greenlee, J.J., Baron, T., Benestad, S., Brown, P., Deslys, J. 2015. Transmission of scrapie prions to primate after an extended silent incubation period. Scientific Reports. 5:11573.

 

Interpretive Summary: The transmissible spongiform encephalopathies (also called prion diseases) are fatal neurodegenerative diseases that affect animals and humans. The agent of prion diseases is a misfolded form of the prion protein that is resistant to breakdown by the host cells. Since all mammals express prion protein on the surface of various cells such as neurons, all mammals are, in theory, capable of replicating prion diseases. One example of a prion disease, bovine spongiform encephalopathy (BSE; also called mad cow disease), has been shown to infect cattle, sheep, exotic undulates, cats, non-human primates, and humans when the new host is exposed to feeds or foods contaminated with the disease agent. The purpose of this study was to test whether non-human primates (cynomologous macaque) are susceptible to the agent of sheep scrapie. After an incubation period of approximately 10 years a macaque developed progressive clinical signs suggestive of neurologic disease. Upon postmortem examination and microscopic examination of tissues, there was a widespread distribution of lesions consistent with a transmissible spongiform encephalopathy. This information will have a scientific impact since it is the first study that demonstrates the transmission of scrapie to a non-human primate with a close genetic relationship to humans. This information is especially useful to regulatory officials and those involved with risk assessment of the potential transmission of animal prion diseases to humans. Technical Abstract: Classical bovine spongiform encephalopathy (c-BSE) is an animal prion disease that also causes variant Creutzfeldt-Jakob disease in humans. Over the past decades, c-BSE's zoonotic potential has been the driving force in establishing extensive protective measures for animal and human health.

 

*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.

 

*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.

 

*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.

 


 

***This information will have a scientific impact since it is the first study that demonstrates the transmission of scrapie to a non-human primate with a close genetic relationship to humans. This information is especially useful to regulatory officials and those involved with risk assessment of the potential transmission of animal prion diseases to humans.

 

***This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated. Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.

 


 

why do we not want to do TSE transmission studies on chimpanzees $

 

5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.

 

snip...

 

R. BRADLEY

 


 

”The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite it’s subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA veiwed it as a wildlife problem and consequently not their province!” page 26.

 


 

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

 

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

 


 

MAD COW DISEASE HAS BEEN IN THE USA FOR DECADES, AND I BELIEVE IT WAS IN THE USA FIRST, PLEASE SEE ;

 

Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.

 

snip...

 

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

 


 


 


 

PL1

 

Using in vitro prion replication for high sensitive detection of prions and prionlike proteins and for understanding mechanisms of transmission.

 

Claudio Soto

 

Mitchell Center for Alzheimer's diseases and related Brain disorders, Department of Neurology, University of Texas Medical School at Houston.

 

Prion and prion-like proteins are misfolded protein aggregates with the ability to selfpropagate to spread disease between cells, organs and in some cases across individuals. I n T r a n s m i s s i b l e s p o n g i f o r m encephalopathies (TSEs), prions are mostly composed by a misfolded form of the prion protein (PrPSc), which propagates by transmitting its misfolding to the normal prion protein (PrPC). The availability of a procedure to replicate prions in the laboratory may be important to study the mechanism of prion and prion-like spreading and to develop high sensitive detection of small quantities of misfolded proteins in biological fluids, tissues and environmental samples. Protein Misfolding Cyclic Amplification (PMCA) is a simple, fast and efficient methodology to mimic prion replication in the test tube. PMCA is a platform technology that may enable amplification of any prion-like misfolded protein aggregating through a seeding/nucleation process. In TSEs, PMCA is able to detect the equivalent of one single molecule of infectious PrPSc and propagate prions that maintain high infectivity, strain properties and species specificity. Using PMCA we have been able to detect PrPSc in blood and urine of experimentally infected animals and humans affected by vCJD with high sensitivity and specificity. Recently, we have expanded the principles of PMCA to amplify amyloid-beta (Aβ) and alphasynuclein (α-syn) aggregates implicated in Alzheimer's and Parkinson's diseases, respectively. Experiments are ongoing to study the utility of this technology to detect Aβ and α-syn aggregates in samples of CSF and blood from patients affected by these diseases.

 

=========================

 

***Recently, we have been using PMCA to study the role of environmental prion contamination on the horizontal spreading of TSEs. These experiments have focused on the study of the interaction of prions with plants and environmentally relevant surfaces. Our results show that plants (both leaves and roots) bind tightly to prions present in brain extracts and excreta (urine and feces) and retain even small quantities of PrPSc for long periods of time. Strikingly, ingestion of prioncontaminated leaves and roots produced disease with a 100% attack rate and an incubation period not substantially longer than feeding animals directly with scrapie brain homogenate. Furthermore, plants can uptake prions from contaminated soil and transport them to different parts of the plant tissue (stem and leaves). Similarly, prions bind tightly to a variety of environmentally relevant surfaces, including stones, wood, metals, plastic, glass, cement, etc. Prion contaminated surfaces efficiently transmit prion disease when these materials were directly injected into the brain of animals and strikingly when the contaminated surfaces were just placed in the animal cage. These findings demonstrate that environmental materials can efficiently bind infectious prions and act as carriers of infectivity, suggesting that they may play an important role in the horizontal transmission of the disease.

 

========================

 

Since its invention 13 years ago, PMCA has helped to answer fundamental questions of prion propagation and has broad applications in research areas including the food industry, blood bank safety and human and veterinary disease diagnosis.

 


 

see ;

 


 


 


 


 


 

Wednesday, December 16, 2015

 

Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission

 

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 ***

 


 

Circulation of prions within dust on a scrapie affected farm

 

Kevin C Gough1, Claire A Baker2, Hugh A Simmons3, Steve A Hawkins3 and Ben C Maddison2*

 

Abstract

 

Prion diseases are fatal neurological disorders that affect humans and animals. Scrapie of sheep/goats and Chronic Wasting Disease (CWD) of deer/elk are contagious prion diseases where environmental reservoirs have a direct link to the transmission of disease. Using protein misfolding cyclic amplification we demonstrate that scrapie PrPSc can be detected within circulating dusts that are present on a farm that is naturally contaminated with sheep scrapie. The presence of infectious scrapie within airborne dusts may represent a possible route of infection and illustrates the difficulties that may be associated with the effective decontamination of such scrapie affected premises.

 

snip...

 

Discussion

 

We present biochemical data illustrating the airborne movement of scrapie containing material within a contaminated farm environment. We were able to detect scrapie PrPSc within extracts from dusts collected over a 70 day period, in the absence of any sheep activity. We were also able to detect scrapie PrPSc within dusts collected within pasture at 30 m but not at 60 m distance away from the scrapie contaminated buildings, suggesting that the chance of contamination of pasture by scrapie contaminated dusts decreases with distance from contaminated farm buildings. PrPSc amplification by sPMCA has been shown to correlate with infectivity and amplified products have been shown to be infectious [14,15]. These experiments illustrate the potential for low dose scrapie infectivity to be present within such samples. We estimate low ng levels of scrapie positive brain equivalent were deposited per m2 over 70 days, in a barn previously occupied by sheep affected with scrapie. This movement of dusts and the accumulation of low levels of scrapie infectivity within this environment may in part explain previous observations where despite stringent pen decontamination regimens healthy lambs still became scrapie infected after apparent exposure from their environment alone [16]. The presence of sPMCA seeding activity and by inference, infectious prions within dusts, and their potential for airborne dissemination is highly novel and may have implications for the spread of scrapie within infected premises. The low level circulation and accumulation of scrapie prion containing dust material within the farm environment will likely impede the efficient decontamination of such scrapie contaminated buildings unless all possible reservoirs of dust are removed. Scrapie containing dusts could possibly infect animals during feeding and drinking, and respiratory and conjunctival routes may also be involved. It has been demonstrated that scrapie can be efficiently transmitted via the nasal route in sheep [17], as is also the case for CWD in both murine models and in white tailed deer [18-20].

 

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.

 


 

Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES

 

Title: Scrapie transmits to white-tailed deer by the oral route and has a molecular profile similar to chronic wasting disease

 

Authors

 

item Greenlee, Justin item Moore, S - item Smith, Jodi - item Kunkle, Robert item West Greenlee, M -

 

Submitted to: American College of Veterinary Pathologists Meeting Publication Type: Abstract Only Publication Acceptance Date: August 12, 2015 Publication Date: N/A Technical Abstract: The purpose of this work was to determine susceptibility of white-tailed deer (WTD) to the agent of sheep scrapie and to compare the resultant PrPSc to that of the original inoculum and chronic wasting disease (CWD). We inoculated WTD by a natural route of exposure (concurrent oral and intranasal (IN); n=5) with a US scrapie isolate. All scrapie-inoculated deer had evidence of PrPSc accumulation. PrPSc was detected in lymphoid tissues at preclinical time points, and deer necropsied after 28 months post-inoculation had clinical signs, spongiform encephalopathy, and widespread distribution of PrPSc in neural and lymphoid tissues. Western blotting (WB) revealed PrPSc with 2 distinct molecular profiles. WB on cerebral cortex had a profile similar to the original scrapie inoculum, whereas WB of brainstem, cerebellum, or lymph nodes revealed PrPSc with a higher profile resembling CWD. Homogenates with the 2 distinct profiles from WTD with clinical scrapie were further passaged to mice expressing cervid prion protein and intranasally to sheep and WTD. In cervidized mice, the two inocula have distinct incubation times. Sheep inoculated intranasally with WTD derived scrapie developed disease, but only after inoculation with the inoculum that had a scrapie-like profile. The WTD study is ongoing, but deer in both inoculation groups are positive for PrPSc by rectal mucosal biopsy. In summary, this work demonstrates that WTD are susceptible to the agent of scrapie, two distinct molecular profiles of PrPSc are present in the tissues of affected deer, and inoculum of either profile readily passes to deer.

 


 


 

White-tailed Deer are Susceptible to Scrapie by Natural Route of Infection

 

Jodi D. Smith, Justin J. Greenlee, and Robert A. Kunkle; Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS

 

Interspecies transmission studies afford the opportunity to better understand the potential host range and origins of prion diseases. Previous experiments demonstrated that white-tailed deer are susceptible to sheep-derived scrapie by intracranial inoculation. The purpose of this study was to determine susceptibility of white-tailed deer to scrapie after a natural route of exposure. Deer (n=5) were inoculated by concurrent oral (30 ml) and intranasal (1 ml) instillation of a 10% (wt/vol) brain homogenate derived from a sheep clinically affected with scrapie. Non-inoculated deer were maintained as negative controls. All deer were observed daily for clinical signs. Deer were euthanized and necropsied when neurologic disease was evident, and tissues were examined for abnormal prion protein (PrPSc) by immunohistochemistry (IHC) and western blot (WB). One animal was euthanized 15 months post-inoculation (MPI) due to an injury. At that time, examination of obex and lymphoid tissues by IHC was positive, but WB of obex and colliculus were negative. Remaining deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 MPI. Tissues from these deer were positive for scrapie by IHC and WB. Tissues with PrPSc immunoreactivity included brain, tonsil, retropharyngeal and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. This work demonstrates for the first time that white-tailed deer are susceptible to sheep scrapie by potential natural routes of inoculation. In-depth analysis of tissues will be done to determine similarities between scrapie in deer after intracranial and oral/intranasal inoculation and chronic wasting disease resulting from similar routes of inoculation.

 

see full text ;

 


 

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

 


 

White-tailed deer are susceptible to the agent of sheep scrapie by intracerebral inoculation

 

snip...

 

It is unlikely that CWD will be eradicated from free-ranging cervids, and the disease is likely to continue to spread geographically [10]. However, the potential that white-tailed deer may be susceptible to sheep scrapie by a natural route presents an additional confounding factor to halting the spread of CWD. This leads to the additional speculations that

 

1) infected deer could serve as a reservoir to infect sheep with scrapie offering challenges to scrapie eradication efforts and

 

2) CWD spread need not remain geographically confined to current endemic areas, but could occur anywhere that sheep with scrapie and susceptible cervids cohabitate.

 

This work demonstrates for the first time that white-tailed deer are susceptible to sheep scrapie by intracerebral inoculation with a high attack rate and that the disease that results has similarities to CWD. These experiments will be repeated with a more natural route of inoculation to determine the likelihood of the potential transmission of sheep scrapie to white-tailed deer. If scrapie were to occur in white-tailed deer, results of this study indicate that it would be detected as a TSE, but may be difficult to differentiate from CWD without in-depth biochemical analysis.

 


 


 

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.

 


 

White-tailed Deer are Susceptible to Scrapie by Natural Route of Infection

 

Jodi D. Smith, Justin J. Greenlee, and Robert A. Kunkle; Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS

 

Interspecies transmission studies afford the opportunity to better understand the potential host range and origins of prion diseases. Previous experiments demonstrated that white-tailed deer are susceptible to sheep-derived scrapie by intracranial inoculation. The purpose of this study was to determine susceptibility of white-tailed deer to scrapie after a natural route of exposure. Deer (n=5) were inoculated by concurrent oral (30 ml) and intranasal (1 ml) instillation of a 10% (wt/vol) brain homogenate derived from a sheep clinically affected with scrapie. Non-inoculated deer were maintained as negative controls. All deer were observed daily for clinical signs. Deer were euthanized and necropsied when neurologic disease was evident, and tissues were examined for abnormal prion protein (PrPSc) by immunohistochemistry (IHC) and western blot (WB). One animal was euthanized 15 months post-inoculation (MPI) due to an injury. At that time, examination of obex and lymphoid tissues by IHC was positive, but WB of obex and colliculus were negative. Remaining deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 MPI. Tissues from these deer were positive for scrapie by IHC and WB. Tissues with PrPSc immunoreactivity included brain, tonsil, retropharyngeal and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. This work demonstrates for the first time that white-tailed deer are susceptible to sheep scrapie by potential natural routes of inoculation. In-depth analysis of tissues will be done to determine similarities between scrapie in deer after intracranial and oral/intranasal inoculation and chronic wasting disease resulting from similar routes of inoculation.

 

see full text ;

 


 

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.

 


 

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

 


 

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

 


 


 

Wednesday, October 17, 2012

 

Prion Remains Infectious after Passage through Digestive System of American Crows (Corvus brachyrhynchos)

 


 

Chronic Wasting Disease Susceptibility of Four North American Rodents

 

Chad J. Johnson1*, Jay R. Schneider2, Christopher J. Johnson2, Natalie A. Mickelsen2, Julia A. Langenberg3, Philip N. Bochsler4, Delwyn P. Keane4, Daniel J. Barr4, and Dennis M. Heisey2 1University of Wisconsin School of Veterinary Medicine, Department of Comparative Biosciences, 1656 Linden Drive, Madison WI 53706, USA 2US Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison WI 53711, USA 3Wisconsin Department of Natural Resources, 101 South Webster Street, Madison WI 53703, USA 4Wisconsin Veterinary Diagnostic Lab, 445 Easterday Lane, Madison WI 53706, USA *Corresponding author email: cjohnson@svm.vetmed.wisc.edu

 

We intracerebrally challenged four species of native North American rodents that inhabit locations undergoing cervid chronic wasting disease (CWD) epidemics. The species were: deer mice (Peromyscus maniculatus), white-footed mice (P. leucopus), meadow voles (Microtus pennsylvanicus), and red-backed voles (Myodes gapperi). The inocula were prepared from the brains of hunter-harvested white-tailed deer from Wisconsin that tested positive for CWD. Meadow voles proved to be most susceptible, with a median incubation period of 272 days. Immunoblotting and immunohistochemistry confirmed the presence of PrPd in the brains of all challenged meadow voles. Subsequent passages in meadow voles lead to a significant reduction in incubation period. The disease progression in red-backed voles, which are very closely related to the European bank vole (M. glareolus) which have been demonstrated to be sensitive to a number of TSEs, was slower than in meadow voles with a median incubation period of 351 days. We sequenced the meadow vole and red-backed vole Prnp genes and found three amino acid (AA) differences outside of the signal and GPI anchor sequences. Of these differences (T56-, G90S, S170N; read-backed vole:meadow vole), S170N is particularly intriguing due its postulated involvement in "rigid loop" structure and CWD susceptibility. Deer mice did not exhibit disease signs until nearly 1.5 years post-inoculation, but appear to be exhibiting a high degree of disease penetrance. White-footed mice have an even longer incubation period but are also showing high penetrance. Second passage experiments show significant shortening of incubation periods. Meadow voles in particular appear to be interesting lab models for CWD. These rodents scavenge carrion, and are an important food source for many predator species. Furthermore, these rodents enter human and domestic livestock food chains by accidental inclusion in grain and forage. Further investigation of these species as potential hosts, bridge species, and reservoirs of CWD is required.

 

please see ;

 


 


 

”The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite it’s subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA veiwed it as a wildlife problem and consequently not their province!” page 26.

 


 

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

 

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

 


 

MAD COW DISEASE HAS BEEN IN THE USA FOR DECADES, AND I BELIEVE IT WAS IN THE USA FIRST, PLEASE SEE ;

 

Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.

 

snip...

 

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

 


 


 


 

Chronic Wasting Disease CWD TSE Prion Roundup USA April 1, 2016

 

Wednesday, March 30, 2016

 

ARIZONA CHRONIC WASTING DISEASE CWD TSE PRION SURVEILLANCE AND TESTING PROGRAM

 


 

Tuesday, March 29, 2016

 

ALABAMA CHRONIC WASTING DISEASE CWD TSE PRION SURVEILLANCE AND TESTING PROGRAM?

 


 

Tuesday, March 29, 2016

 

Maryland Department of Natural Resources Five Deer Test Positive for Chronic Wasting Disease ONE OUTSIDE CWD MANAGEMENT ZONE

 


 

Thursday, March 24, 2016

 

ARKANSAS FIRST BATCH OF TARGET TESTS REVEALS 19 ADDITIONAL CWD-POSITIVE CERVIDS

 


 

Friday, March 18, 2016

 

Michigan confirms additional CWD-positive free-ranging, white-tailed deer, bringing the total to seven

 


 

Wednesday, March 16, 2016

 

Wisconsin CWD sample survey 2015 confirms 290 cases of Chronic Wasting Disease TSE Prion

 


 

Thursday, March 10, 2016

 

WYOMING RIDE EM COWBOY HELICOPTER WRANGLING RAMBO STYLE DEER BULLDOGGING RODEO FOR CWD VIDEO

 

CHRONIC WASTING DISEASE: The Final Epidemic

 


 

Tuesday, March 08, 2016

 

Oklahoma Chronic Wasting Disease CWD of Deer and Elk Surveillance, Testing, and Preparedness ???

 


 

Wednesday, March 02, 2016

 

Kansas Chronic Wasting Disease CWD TSE Prion 52 cases 2015 updated report 'ALARMING'

 


 

Sunday, March 06, 2016

 

Missouri 2015-2016 CWD Surveillance Summary to Date, with confirmed cases mounting

 


 

TEXAS CWD TESTING TOTAL FIGURES ??? anyone’s guess to date. TAHC et al should take up Arkansas reporting of test results to the public and open discussion. ...

 

Friday, February 26, 2016

 

TEXAS Hartley County Mule Deer Tests Positive for Chronic Wasting Disease CWD TSE Prion

 


 

Friday, February 26, 2016

 

Pennsylvania Monitoring the Growing Threat of Chronic Wasting Disease CWD TSE Prion

 


 

Friday, February 05, 2016

 

TEXAS NEW CHRONIC WASTING DISEASE CWD CASE DISCOVERD AT CAPTIVE DEER RELEASE SITE

 


 

Tuesday, February 02, 2016

 

Illinois six out of 19 deer samples tested positive for CWD in the Oswego zone of Kendall County

 


 

Friday, February 05, 2016

 

IOWA Two Wild Deer Test Positive for Chronic Wasting Disease in Allamakee County

 


 

Friday, January 29, 2016

 

NEBRASKA Three Positives for CWD Found in Recent Testing of Deer

 


 

Friday, November 20, 2015

 

ODNR Takes Action to Monitor Chronic Wasting Disease in Ohio's Deer Herd

 


 

Friday, October 23, 2015

 

Ohio Wildlife Council Passes Rule to Help Monitor CWD

 


 

Wednesday, August 05, 2015

 

Ohio confirms to me Chronic Wasting Disease CWD Spreads 19 confirmed cases to date

 


 

Wednesday, February 11, 2015

 

World Class Whitetails quarantined CWD deer Daniel M. Yoder charged with two counts of tampering with evidence

 


 

Thursday, October 23, 2014

 

*** FIRST CASE OF CHRONIC WASTING DISEASE CONFIRMED IN OHIO ON PRIVATE PRESERVE

 


 

Monday, June 11, 2012

 

*** OHIO Captive deer escapees and non-reporting ***

 


 

Thursday, March 31, 2016

 

Chronic Wasting Disease CWD TSE Prion Roundup USA April 1, 2016

 


 

Friday, February 05, 2016

 

Report of the Committee on Wildlife Diseases FY2015 CWD TSE PRION Detections in Farmed Cervids and Wild

 


 

Saturday, February 6, 2016

 

Secretary's Advisory Committee on Animal Health; Meeting [Docket No. APHIS-2016-0007] Singeltary Submission

 



 
 
Terry S. Singeltary Sr. Declares a DECLARATION OF EXTRAORDINARY EMERGENCY DUE TO A FOREIGN ANIMAL DISEASE TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION CHRONIC WASTING DISEASE CWD IN THE UNITED STATES AND NORTH AMERICA.
 
Monday, April 11, 2016
 
DECLARATION OF EXTRAORDINARY EMERGENCY DUE TO A FOREIGN ANIMAL DISEASE TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY TSE PRION CHRONIC WASTING DISEASE CWD IN THE UNITED STATES AND NORTH AMERICA
 

 

Terry S. Singeltary Sr.

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