Tuesday, January 19, 2016

Wisconsin Second CWD-positive deer found in Oneida County 5-year-old buck shot at Three Lakes Trophy Ranch LLC agency received the CWD-positive report on the animal Dec. 29

Second CWD-positive deer found in Oneida County By Paul A. Smith of the Journal Sentinel

 

Jan. 18, 2016

 

A second CWD-positive deer has been reported at an Oneida County shooting preserve, according to the Department of Agriculture, Trade and Consumer Protection.

 

The 5-year-old buck was shot at Three Lakes Trophy Ranch LLC in Three Lakes. The agency received the CWD-positive report on the animal Dec. 29.

 

A 3-year-old buck at the facility also tested positive for the disease in November, initiating a baiting and feeding ban in Oneida, Forest and Vilas counties.

 

Officials with DATCP said Friday there was no plan to depopulate the facility since "none of the deer are removed alive and all are tested as they leave."

 

 At least some residents in the area, however, are concerned about the potential for the disease to spread to wild deer if animals were to escape the captive facility or come into contact along the facility's perimeter.

 

The recent CWD-positive findings, as well as other deer management issues, will be discussed Thursday evening at a special meeting of the Vilas County Deer Advisory Council.

 

According to records from December, Three Lakes Trophy Ranch had about 425 deer on 570 acres.

 


 

Note: Oneida, Forest and Vilas counties have been added to the CWD-affected counties effective Jan. 11, 2016

 


 

As of 2015 there were 421 registered deer farms in Wisconsin. White-tailed deer farming is regulated and licensed by the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) [exit DNR]. However the Department of Natural Resources (DNR) is responsible for regulating white-tailed deer farm fencing. Before you can register your farm with DATCP you must have your fence inspected and receive a deer farm fence certificate from the DNR.

 


 

State pays farmer $298,000 for infected deer herd

 

By Paul A. Smith of the Journal Sentinel

 

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.

 

The state has a maximum payment of $1,500 per animal in such cases; Vojtik received $1,310 each.

 

The adult deer killed at Fairchild Whitetails were tested for disease. Including those tested before depopulation, 33 deer at the facility were CWD-positive, according to the DATCP.

 

The CWD-positive deer on Vojtik's farm were the first and only detected to date in Eau Claire County and triggered a deer baiting and feeding ban in Eau Claire, Clark and Jackson counties.

 

More than a dozen deer escaped the facility last year but all were captured or killed, according to Rick Rosen, regional warden supervisor for the Department of Natural Resources.

 

In Wisconsin, the DATCP has authority over deer and elk farms while the DNR has authority over the fences at such facilities and deer and elk outside them.

 

Under an agreement with state officials, Vojtik will maintain the farm's fences for five years and not put deer or other cervids in the area. Agents with the DATCP will disinfect the property, said Paul McGraw, DATCP veterinarian.

 

The 228 deer had been held in an enclosure of about 10 acres.

 

Chronic wasting disease has been found at 13 captive cervid facilities in Wisconsin, according to DATCP records.

 

Second CWD finding in Oneida County: A second CWD-positive deer has been reported at an Oneida County shooting preserve, according to the DATCP.

 

The 5-year-old buck was shot at Three Lakes Trophy Ranch LLC in Three Lakes. The agency received the CWD-positive report on the animal Dec. 29.

 

A 3-year-old buck at the facility also tested positive for the disease in November, initiating a baiting and feeding ban in Oneida, Forest and Vilas counties.

 

Officials with the DATCP said Friday there was no plan to depopulate the facility. According to records from December, Three Lakes Trophy Ranch had about 425 deer on 570 acres.

 

The captive animals are the only deer to test positive for CWD in that portion of the Northwoods, including the Upper Peninsula of Michigan.

 

Last year, Michigan officials unveiled a campaign called "Keep the U.P. CWD Free!" It is illegal to bring whole deer carcasses from Wisconsin into Michigan.

 

Chronic wasting disease was identified in Colorado in 1967. The disease, among a family of transmissible spongiform encephalopathies including Mad Cow Disease and Creutzfeldt-Jakob, is fatal to deer, elk and moose. The disease was first detected in Wisconsin in 2002 near Mount Horeb. As of this month, 41 of the state's 72 counties are considered "CWD-affected" by the DNR.

 

Meat from a CWD-positive animal should not be eaten, according to health officials.

 

DNR hiring for creel survey: The DNR is accepting applications for three fisheries technicians to conduct creel surveys on Lake Michigan.

 

The limited-term employee positions will run from about March 7 to Oct. 31; the jobs will be based in Mishicot, Plymouth and Sturtevant.

 

According to the job description, candidates must be able to accurately identify common Lake Michigan fish; have good oral and written communication skills; be able to work independently with limited supervision; be able to approach anglers on piers and breakwaters, rocky shorelines, open sand, cobble beaches and along streams and rivers over uneven terrain; and be willing to work in inclement weather.

 

The jobs will pay $11.50 to $12.50 per hour depending on experience and training. Work is required on weekends and holidays.

 

For application materials and more information, visit dnr.wi.gov/employment. The application deadline is Feb. 2.

 

Interviews are planned the week of Feb. 8 at the DNR's Plymouth Service Center.

 

© 2016, Journal Sentinel Inc. All rights reserved.

 

About Paul A. Smith Paul A. Smith covers outdoors and conservation issues.

 

@mjsps psmith@journalsentinel.com 414-224-2313

 


 

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:

 


 

$298,770 + $465,000

 

Friday, December 04, 2015

 

Wisconsin CWD-positive white-tailed deer found on Oneida County hunting preserve December 3, 2015

 


 

Thursday, November 19, 2015

 

Wisconsin Eau Claire Co. deer herd two day round of depopulation CWD testing shows 23 positive

 


 

Wednesday, December 16, 2015

 

Wisconsin Chronic wasting disease confirmed in Crawford County buck harvested on private land

 


 

Tuesday, February 11, 2014

 

Wisconsin tracks 81 deer from game farm with CWD buck to seven other states

 


 

 Tuesday, December 17, 2013

 

 Wisconsin Second CWD positive deer found in Grant County

 


 

Monday, December 02, 2013

 

 WISCONSIN CHRONIC WASTING DISEASE CWD DISCOVERED MARATHON COUNTY HUNTING PRESERVE

 


 

 Sunday, November 03, 2013

 

 Wisconsin Second CWD deer found in Portage County

 


 

 Wisconsin : 436 Deer Have Escaped From Farms to Wild

 

 Date: March 18, 2003 Source: Milwaukee Journal Sentinel snip...

 

 Sunday, November 03, 2013

 

 Wisconsin Second CWD deer found in Portage County

 

 Second CWD deer found in Portage County

 

 News Release

 

 Published: November 1, 2013 by the Northwest Region Contact(s): Kris Johansen, DNR area wildlife supervisor, 715-284-1430; Ed Culhane,

 

 DNR communications, 715-781-1683 WISCONSIN RAPIDS – A deer harvested by a bow hunter in southeast Portage County has tested positive for chronic wasting disease, the state Department of Natural Resources reports. This is the second CWD-positive wild deer found in the county. Wildlife biologists in central Wisconsin now are asking bow hunters to assist with increased surveillance for the disease in four separate areas where positives have been confirmed outside the CWD management zone.

 

 CWD is contagious and fatal for deer, elk and moose. “Last fall CWD was discovered for the first time in three wild, white-tailed deer in Adams, Juneau and Portage counties” said DNR area wildlife supervisor Kris Johansen. “Now we have a second positive in a different area of Portage County. To better define the geographic extent of CWD in central Wisconsin, we are focusing additional surveillance around each of these four locations.”

 

 The latest CWD positive deer was harvested Oct. 6 just northwest of Almond in Portage County.

 

 To view where the surveillance focus areas are located, hunters can go to the DNR website and enter “CWD registration” in the key word search, then click on “CWD registration and sampling.” On this page – http://dnr.wi.gov/topic/wildlifehabitat/registersample.html – detailed maps show the precise location of these surveillance circles for the first three positives, the ones in Adams and Juneau counties and the first find in Portage County, located in the northwest corner of the county.

 

 There is also a map showing the two Portage County locations. A new map, showing the precise surveillance area for the fourth positive, in southeast Portage County, will be added to the web page as soon as it is prepared. This page also links to a list of cooperating taxidermists and meat processors where samples can be collected.

 

 The DNR is asking hunters to work with these cooperators to have head and lymph node samples from adult deer – harvested within the four focus areas – removed for testing. To have the sample removed, the hunter can bring the whole deer to one of the listed cooperators or just remove the head with at least three inches of neck attached and bring that in for sampling.

 

 “Please call ahead to set up an appointment,” Johansen said. “These are private business operators who are helping us out, and we want to respect their time and their schedules.” This list will be updated online as new cooperators join the surveillance effort:

 

 • Wisconsin River Meats, N5340 County HH, Mauston 608-847-7413

 

 • A&B Butchering, 6971 Hwy 34, Rudolph 715-435-3893

 

 • Strickly Wild Processing, 140 Buffalo St, Wisconsin Rapids 715-421-0587

 

 • Hartnell's Wild Game Processing, 1925 Cypress Ave., Arkdale 608-339-7288

 

 • Trevor Athens Taxidermy, 982 15th Ave., Arkdale 608-547-6117

 

 • Tall Tines Taxidermy, N2621 Cassidy Road, Mauston 608-547-0818

 

 • Todd's Wildlife Taxidermy, N2148 State 58, Mauston 608-847-7693

 

 • Vollmer Taxidermy, 3631 Plover Road, Plover 715-345-1934

 

 • Field and Stream Taxidermy, 217 S. Front St., Coloma 608-547-1565

 

 • DNR Service Center, 473 Griffith Ave., Wisconsin Rapids 715-421-7813

 

 • Mead Wildlife Area, S2148 County S, Milladore 715-457-6771

 

 • Adams Ranger Station, 532 N. Adams St., Adams 608-339-4819

 

 • Almond Market, 111 Main St., Almond 715-366-2002

 

 Hunters may also have deer from any of the four focus areas tested for CWD by contacting one of these DNR offices:

 

 • Mead Wildlife Area headquarters, S2148 County S, Milladore – 715-457-6771

 

 • WI Rapids Service Center, 473 Griffith Avenue, Wisconsin Rapids – 715-421-7813

 

 • Adams-Friendship Ranger Station, 532 N. Main Street, Adams – 608-339-4819

 

 On the weekends or during warm periods, hunters should remove the deer head with at least three inches of neck attached, freeze the head and then contact the DNR to arrange a drop off. DNR staff will also collect samples from hunter-harvested deer on the opening weekend of the gun deer season. Collection stations and hours will be published prior to the gun deer season. The CWD tests are free to hunters. Each person who submits a head for testing will receive lab results within three or four weeks. http://dnr.wi.gov/news/BreakingNews_Lookup.asp?id=2996

 


 

Friday, February 03, 2012

 

*** Wisconsin Farm-Raised Deer Farms and CWD there from 2012 report Singeltary et al

 


 

 THE YEAR 2000

 

 Stop the madness: CWD threatens Wisconsin's elk, deer and, ultimately, people.

 

 15 July 00

 

 The Isthmus magazine By BRIAN McCOMBIE

 

 Imagine a disease worse than AIDS rippling through Wisconsin's deer herd. One that's always fatal, cannot be tested for in live animals, and has the chance of spreading to anyone who eats the infected venison. Sound like the premise for Michael Crichton's next apocalyptic thriller?

 

 Unfortunately, such a disease already exists in epidemic levels in the wilds of Colorado and Wyoming. It's infected some game farms, too, and Wisconsin game farmers have imported more than 350 elk with the potential for this disease, including elk from farms known to be infected.

 

 "If most people knew what kind of risk this disease poses to free-ranging deer in the state, they'd be very concerned," says Dr. Sarah Hurley, Lands Division administrator for the Department of Natural Resources. The DNR is now testing free-ranging deer around these game farms for the disease: "We're focusing our energies on those areas where we think there's the greatest possibility of transmission."

 

 The malady the DNR's looking for is chronic wasting disease (CWD)--better known, to the extent it is known at all, as mad elk disease. It's a form of the mad cow disease that devastated Britain's cattle industry in the 1980s, scared the bejesus out of the populace, and is believed to have killed at least 70 people to date. An elk or deer with CWD can be listless, may walk in circles, will lose weight and interact progressively less with fellow animals.

 

 The corresponding human affliction is called Creutzfeldt-Jakob disease (pronounced Croytz-feld Yawkob) or CJD. People with CJD experience symptoms similar to Alzheimer's, including memory loss and depression, followed by rapidly progressive dementia and death, usually within one year. While CJD is rare (literally one in a million odds of getting it), over the last few years at least three deer hunters have died of it. There is no proof either way whether they contracted the disease from CWD-infected venison, but new research says it is possible.

 

 All three varieties--mad cow, mad elk and CJD--belong to a family of diseases called transmissible spongiform encephalopathy. These diseases alter the conformation of proteins in the brain called prions; after-death brain samples usually show a series of microscopic holes in and around brain cells.

 

 No one is exactly sure how mad elk disease spreads. At first, transmittal through blood seemed likely, as from mother to fawn. But CWD has moved between adult animals at game farms, leading scientists to conclude that it can be spread through saliva or simple contact. Also, the rates of transmission are higher in areas where animals have the most opportunities for contact. Wisconsin's concentrated population of 1.7 million deer interact freely with each other, and scientific modeling suggests CWD could tear through our deer herd devastatingly fast. Despite the danger, Wisconsin and other states are relying on only sporadic testing and a system of voluntary compliance. It's a system that some say has more holes in it than a CWD-infected brain.

 

 At present, Wisconsin game farm owners, even those harboring elk and deer brought in from farms with known cases of CWD, do not have to call a veterinarian if a deer or elk suddenly dies or acts strange. They're also not required to inform the state Department of Natural Resources (DNR) or the Department of Agriculture, Trade and Consumer Protection (DATCP) if animals escape into the wild.

 

 "The lax attitude is pretty shocking," says John Stauber, a Madison activist and co-author of Mad Cow U.S.A. To protect people and deer, Stauber argues for an immediate importation ban for game farms, plus programs of testing and surveillance. He suggests both DATCP and DNR aren't taking such measures because, as the regulators in charge, they don't want to find the CWD he thinks is likely already in state. "It's in their bureaucratic interest to not [actively] look for CWD in the game farms," says Stauber. "Because if they find it, who's to blame?"

 

 In the wild and especially out west, chronic wasting disease is spreading fast. Northeastern Colorado documented its first case in 1981. By the mid-1990s, samplings of mule deer brains showed 3% to 4% testing positive for CWD. Within a few years, the rate was 8%, and now Larimer County, the center of the endemic area, has a 15% rate of infection among mule deer. It's also being found in deer and elk in Wyoming.

 

 "Fifteen percent of a wild population of animals with this disease is staggering," says Dr. Thomas Pringle, who tracks CWD-type diseases for the Sperling Biomedical Foundation in Eugene, Ore. "It's basically unheard of. This appears to be an unusually virulent strain. with highly efficient horizontal transmission mechanisms."

 

 CWD could eventually spread to Wisconsin on its own, animal to animal. But that would take decades. Game farms, though, provide a mechanism to cut through all that time and distance and drop CWD smack in the middle of the state.

 

 An open-records search by Isthmus reveals that the first shipment of farm elk from areas with CWD in the wild occurred in 1992, with 66 Colorado elk going to a game farm in Plymouth. In April 1998, DATCP was informed that a Bloomer game farm had purchased one elk from a Nebraska farm later found to be CWD-infected. This prompted a Sept. 15, 1998, memo from Steven Miller, head of the DNR's Lands Division, to Secretary George Meyer, with copies to DATCP chief Ben Brancel and Gov. Tommy Thompson. In it, Miller recommends that Wisconsin follow the lead of Montana (which found CWD on two game farms) and place "a moratorium on the importation of all game farm animals.... At present it appears the only way to help assure the disease does not spread into Wisconsin."

 

 But the moratorium was never put in place, so it's possible that even more elk potentially carrying CWD are now in state.

 

 Instead of a moratorium, Wisconsin has opted for testing. It is among 12 states and two Canadian provinces that currently test deer for CWD. Last year, the Wisconsin DNR began testing road- and hunter-killed deer in 1999 within a five-mile radius of game farms that have brought in elk from CWD-infected areas. Test areas include all or part of Fond du Lac, Dodge, Jefferson, Sheboygan and Washington counties. All of the approximately 250 brains examined in 1999 came back negative; this year, 500 to 600 deer will be tested.

 

 Meanwhile, DATCP is asking owners of game farms that have animals from herds known to have cases of CWD infection to voluntarily enter a surveillance program. The agency's top veterinarian, Dr. Clarence Siroky, argues that voluntary compliance makes more sense than a moratorium because, ban or no ban, game farm operators "are going to find a way to bring these animals into the state. We don't have police patrols and impregnable borders to keep anything in or out."

 

 With voluntary compliance, Siroky says, at least there are records of animals entering the state. So if CWD or other diseases are discovered, the animals can be traced back to their original herds and other farms they may have been at. "It's better to know where the animals are coming in from," he insists.

 

 Siroky may be right that an importation ban would result in some game farms smuggling in animals. But currently, game farmers can bring in any deer or elk, even those from known CWD-infected areas, so long as they can produce a health certificate showing the animal's been tested. The problem is that no test exists to find CWD in live animals. Animals can carry CWD for years and still look healthy, so some of the 370 elk shipped into Wisconsin between 1996 and 1999 from CWD areas could have the disease. The odds are even higher for animals purchased from farms later found to have CWD.

 

 Wisconsin has approximately 100 deer or elk farms and they're big business. On the Internet, prices for elk calves start at $1,500, and breeding bulls go for up to $20,000. Some farms sell venison and the velvet that peels from new elk antlers (considered an aphrodisiac in Asia). Others offer "hunts" costing between $1,000 and $5,000 for trophy deer, to more than $10,000 for bull elk with massive antlers.

 

 Given these economics, it's reasonable to question why anyone with a suspicion of CWD in his or her herd would call in state regulators or a vet. A farm with a proven CWD case, confirms Dr. Robert Ehlenfeldt, DATCP's director of Animal Disease Control, would be shut down indefinitely.

 

 And if a problem develops on a Wisconsin game farm, there's no guarantee that's where it will stay. Dr. Hurley says even fenced-in animals have easy nose-to-nose contact with wild and other farmed animals. Besides, as the DNR's chief of special operations Thomas Solin has documented, many game farms are not secure. Gates are sometimes left open. Fences rust and break, rot and topple, get crushed by fallen trees. Even if game farm animals don't escape, such breaches allow wild deer to get in, mingle with the farmed deer and elk, then leave.

 

 Unlike other diseases, there's no test for CWD in living animals because it doesn't create an immune system counter-response, detectable through blood analysis. You can't kill CWD and related diseases by cooking the meat. One test Stauber recounts in Mad Cow U.S.A. found that scrapie, a sheep form of CWD, stayed viable after a full hour at 680 degrees Fahrenheit. Most disinfectants don't kill these diseases, either, and they can exist in the soil for years.

 

 And while diseases like mad cow and mad elk do have some trouble jumping from species to species, it can happen. This May, Byron Caughey of the National Institutes of Health announced that he had converted human brain materials with mad-elk-contaminated brain matter at rates roughly equal to the transfer between mad cow and humans.

 

 Says Dr. Pringle, referring to Caughey's work, "CWD may not transmit that easily, but the rate isn't zero." Pringle notes that the test Caughey used has been a very reliable proxy in the past in determining transmission possibilities for other diseases, including mad cow.

 

 Once they jump the species barrier, transmissible spongiform encephalopathy diseases adapt to fit the new host and are then passed on rather easily within that species. Unfortunately, says Pringle, no one is trying to determine if CWD has jumped into people as Creutzfeldt-Jakob disease. Making matters more difficult is the fact that the disease can incubate for decades before symptoms are seen.

 

 In states with CWD-infected deer, thousands of people have undoubtedly been exposed to CWD-infected venison. A February 1998 Denver Post article tells of one hunter who's venison tested positive for CWD. By the time he was notified, his meat had already been ground up and mixed with meat from hundreds of other deer for venison sausage.

 

 With AIDS, Pringle notes, there was a definite overreaction, with people initially afraid to even shake hands with people infected with the virus. Looking at the CWD situation in Colorado, he says there's been complete underreaction. "It's like, oh, what the hell. Nobody's died yet--so keep eating the venison!'" Pringle worries that if the disease is found in humans, it will be so only after years of spreading through the human community.

 

 Looking over documents obtained by Isthmus through its open-records request, Stauber says DATCP is behaving more like a lobbyist for the game farm industry than an agency bent on protecting Wisconsin's people from CWD. He points to DATCP's Cervidae Advisory Committee as a prime example. In a Nov. 11, 1998, memo from Siroky to DATCP secretary Ben Brancel, Siroky notes that the committee is needed to "obtain information from the public concerning disease regulation" of farmed deer and elk, and "to help formulate action plans for importation requirements, prevention and control" of CWD. But of the 12 people Siroky nominates, one's a DNR warden, one's a DATCP employee, and the other 10 are game farm owners. And two of these owners were among those DATCP knew had purchased elk from farms at high risk of having CWD.

 

 "There's no significant input from anyone else," says Stauber. "Farmers, deer hunters and consumers are all left out. Meanwhile, the government's failing to take all necessary precautions to alert the public to this potential health threat."

 


 

 Sunday, January 17, 2016

 

Texas 10,000 deer in Texas tested for deadly disease CWD TSE, but not tested much in the most logical place, the five-mile radius around the Medina County captive-deer facility where it was discovered

 


 

Friday, January 15, 2016

 

TEXAS PARKS & WILDLIFE CWD Ante-Mortem Testing Symposium Texas Disposal Systems Events Pavilion January 12, 2016

 


 

DNR to hold CWD meeting in DeWitt Township Tuesday

 

Tom Thelen, Lansing State Journal 12:13 p.m. EST January 11, 2016

 

Tests confirm deer taken in Watertown Twp. positive for CWD

 


 

Wednesday, December 30, 2015

 

Michigan Deer suspected positive for CWD found in Watertown Township; Jan. 12 public meeting set

 


 

Thursday, December 10, 2015

 

Wyoming Game and Fish seeks public comment on draft of updated CWD plan

 


 

Tuesday, December 08, 2015

 

Wyoming Game and Fish finds CWD in new elk hunt area in Johnson County

 


 

Friday, November 27, 2015

 

Wyoming Game and Fish finds CWD in new Deer Hunt Area near Sheridan

 


 

Monday, November 16, 2015

 

*** Wyoming Latest round of testing CWD surveillance program has found the disease in three new hunt areas

 


 

Wyoming WGF Commission Meeting 11/6/2015 Afternoon Edition Vidoe

 

CWD starts at minute 58:51 of first hour of meeting discussion of previous models predicting extinction of deer population and elk population.

 

please mark hour 1:02 where remarks were made about potential resistant genes and prolonged survival, however a recent study (I posted directly next after youtube link) where it states ;

 

‘’Our study also demonstrates that mice expressing the deer S96-PRNP allele, previously shown to be resistant to various cervid prions, are susceptible to H95+ CWD prions. The potential for the generation of novel strains raises the possibility of an expanded host range for CWD. ‘’

 

hour minute mark 1:03

 

captive Elk study

 

39 femail elk calves captured on National Elk Refuge In Jackson, WY

 

Transported to WGFD Thorne-Williams Wildlife Research Unit (Sybille, TWWRU)

 

Worst-case scenario for prion exposure

 

Genotypes

 

-27 M/M132 (69.2%)

 

-11 M/L132 (28.2%)

 

-1 L/L132 (2.6%)

 

38 of 39 elk died over 10-year study

 

1 remaining elk was L/L132

 

still alive and remained negative for PrPCWD by rectal biopsy

 

Appears healthy, weighs 242kg, and bore healthy calf in May, 2012

 

CWD infection rate in this study ???

 


 

> During the analysis, 37 of 39 elk died, all of which were positive for CWD.

 


 

*** Our study also demonstrates that mice expressing the deer S96-PRNP allele, previously shown to be resistant to various cervid prions, are susceptible to H95+ CWD prions. ***

 

*** The potential for the generation of novel strains raises the possibility of an expanded host range for CWD. ***

 

Deer Prion Proteins Modulate the Emergence and Adaptation of Chronic Wasting Disease Strains

 

Camilo Duque Velásqueza,b, Chiye Kima,c, Allen Herbsta,b, Nathalie Daudea,d, Maria Carmen Garzaa,e, Holger Willea,e, Judd Aikena,b and Debbie McKenziea,c aCentre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada bDepartment of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada cDepartment of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada dDepartment of Medicine, University of Alberta, Edmonton, Alberta, Canada eDepartment of Biochemistry, University of Alberta, Edmonton, Alberta, Canada

 

B. Caughey, Editor

 

+ Author Affiliations

 

ABSTRACT

 

Transmission of chronic wasting disease (CWD) between cervids is influenced by the primary structure of the host cellular prion protein (PrPC). In white-tailed deer, PRNP alleles encode the polymorphisms Q95 G96 (wild type [wt]), Q95 S96 (referred to as the S96 allele), and H95 G96 (referred to as the H95 allele), which differentially impact CWD progression. We hypothesize that the transmission of CWD prions between deer expressing different allotypes of PrPC modifies the contagious agent affecting disease spread. To evaluate the transmission properties of CWD prions derived experimentally from deer of four PRNP genotypes (wt/wt, S96/wt, H95/wt, or H95/S96), transgenic (tg) mice expressing the wt allele (tg33) or S96 allele (tg60) were challenged with these prion agents. Passage of deer CWD prions into tg33 mice resulted in 100% attack rates, with the CWD H95/S96 prions having significantly longer incubation periods. The disease signs and neuropathological and protease-resistant prion protein (PrP-res) profiles in infected tg33 mice were similar between groups, indicating that a prion strain (Wisc-1) common to all CWD inocula was amplified. In contrast, tg60 mice developed prion disease only when inoculated with the H95/wt and H95/S96 CWD allotypes. Serial passage in tg60 mice resulted in adaptation of a novel CWD strain (H95+) with distinct biological properties. Transmission of first-passage tg60CWD-H95+ isolates into tg33 mice, however, elicited two prion disease presentations consistent with a mixture of strains associated with different PrP-res glycotypes. Our data indicate that H95-PRNP heterozygous deer accumulated two CWD strains whose emergence was dictated by the PrPC primary structure of the recipient host. These findings suggest that CWD transmission between cervids expressing distinct PrPC molecules results in the generation of novel CWD strains.

 

IMPORTANCE CWD prions are contagious among wild and captive cervids in North America and in South Korea. We present data linking the amino acid variant Q95H in white-tailed deer cellular prion protein (PrPC) to the emergence of a novel CWD strain (H95+). We show that, upon infection, deer expressing H95-PrPC molecules accumulated a mixture of CWD strains that selectively propagated depending on the PRNP genotype of the host in which they were passaged. Our study also demonstrates that mice expressing the deer S96-PRNP allele, previously shown to be resistant to various cervid prions, are susceptible to H95+ CWD prions. The potential for the generation of novel strains raises the possibility of an expanded host range for CWD.

 


 

*** Our study also demonstrates that mice expressing the deer S96-PRNP allele, previously shown to be resistant to various cervid prions, are susceptible to H95+ CWD prions. ***

 

*** The potential for the generation of novel strains raises the possibility of an expanded host range for CWD. ***

 

UPDATE CWD VACCINE ELK minute mark 1:22:00

 

VACCINE

 

RECOMBINANT PROTEIN FUSION VACCINE

 

Hedlin, PD et al ‘’Design and delivery of a cryptic PrP c epitope for induction of Prp Sc-specific antibody responses.’’ Vaccine 28.4 (2010) 981-988.

 

PAN-PROVINCIAL VACCINE ENTERPRISES (PREVENT)

 

Dose: 2ml IM CWD VACCINE UPDATE IS A FAILURE, I REPEAT, A NEGATIVE RESULTS FOR CWD VACCINE. .tss

 


 

Subject: Bayesian Modeling of Prion Disease Dynamics in Mule Deer Using Population Monitoring and Capture-Recapture Data

 

To date, we are unaware of a study that documents a decrease in CWD prevalence over time in mule deer, white-tailed deer or elk. We briefly consider three plausible explanations for our findings: a) that natural oscillations occur in CWD outbreaks; b) that the outbreak has peaked and is declining to a lower endemic level; or c) that previous management actions were more successful at suppressing the outbreak than originally believed.

 

Sharp & Pastor [41] illustrated that CWD outbreaks may play out as a series of reoccurring epidemics characterized by either stable limit cycles or oscillations that may dampen or amplify as a function of deer density. If this is the case, we would expect today’s declining deer population to feedback on conditions–lowering transmission rates leading to reduced CWD effects and a growing population. Increasing abundance would support higher transmission rates, deer decline, and oscillations of CWD prevalence and deer. Alternatively, Almberg et al. [21] (see also [22–24,41,42]) suggested that CWD outbreaks could reach endemic equilibrium characterized by coexistence of a smaller deer population and CWD. Under these scenarios, population prevalence would reach a lower, constant level after a period of high prevalence and deer decline.

 

Although neither of the foregoing scenarios can be dismissed completely, invoking them ignores the extensive management of this deer population that occurred in the years between the two time points we chose as the basis for our analyses. Management aimed to reduce CWD transmission between 2000 and 2005, which included a combination of (crude and unpopular) focal culling and a broader increase in female harvest, decreased overall deer abundance by about 25%. Analyses carried out shortly after suggested that reductions in deer density had made little impact on CWD prevalence [10]. However, our current findings suggest that these management actions may indeed have attenuated the outbreak. Observed dynamics over the last decade closely approximate those predicted from models by Wild et al. [42] that included a substantial amount of selective predation on CWD-infected individuals. That harvest could be a source of selective mortality is supported by an early notion that CWD-infected deer might be more vulnerable to harvest [43], just as infected deer also appear to be more vulnerable to vehicle collisions and predation [20,33,44]. This offers the possibility that hunting could be used as a more tightly controlled substitute for predation in studies of system responses with CWD and perhaps other similar diseases.

 

The protracted time-scale of the CWD outbreak is much longer than the timespan of our research, which limits our ability to identify the true explanation of our findings. Nonetheless, our research suggests that, at least for the foreseeable future (e.g., decades), mule deer populations sharing the overall survival and infection probabilities estimated from our analyses may persist but likely will not thrive where CWD becomes established as an endemic infectious disease.

 


 

‘’Nonetheless, our research suggests that, at least for the foreseeable future (e.g., decades), mule deer populations sharing the overall survival and infection probabilities estimated from our analyses may persist but likely will not thrive where CWD becomes established as an endemic infectious disease. ‘’

 

*** Bayesian Modeling of Prion Disease Dynamics in Mule Deer Using Population Monitoring and Capture-Recapture Data

 

‘’Mountain lions prey selectively on CWD infected deer [33] and CWD could result in an abundance of vulnerable prey, thereby enhancing mountain lion survival and reproduction [20].’’

 

please see ;

 

‘’preliminary results suggesting that bobcats (Lynx rufus) may be susceptible to white-tailed deer (Odocoileus virginianus) chronic wasting disease agent.’’

 

references on Feline Spongiform Encephalopathy FSE toward the bottom, see ;

 

Assessing Transmissible Spongiform Encephalopathy Species Barriers with an In Vitro Prion Protein Conversion Assay

 

Friday, January 01, 2016

 

Bayesian Modeling of Prion Disease Dynamics in Mule Deer Using Population Monitoring and Capture-Recapture Data

 


 

Tuesday, December 15, 2015

 

Chronic Wasting Disease will cause a Wyoming deer herd to go virtually extinct in 41 years, a five-year study predicts

 

Study: Chronic Wasting Disease kills 19% of deer herd annually

 


 

Saturday, December 12, 2015

 

CHRONIC WASTING DISEASE CWD TSE PRION REPORT DECEMBER 14, 2015

 


 

Monday, January 11, 2016

 

INDIANA SB109 HIGH FENCE HUNTING LEGISLATION AND RISK FACTORS FOR CHRONIC WASTING DISEASE CWD TSE PRION

 


 

Disease in Deer and Elk

 

Chris Siepker1, Nicholas Haley1, W. David Walter2, Matteo Manca3, Laura Hoon-Hanks4, Ryan Monello5, Jenny Powers5, Justin Greenlee6 , Bruce Thomsen7 , Aaron Lehmkuhl7, Gordon Mitchell8, Tracy Nichols9,Byron Caughey3, Edward Hoover4, and Juergen Richt1.

 

1. Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan KS USA 2. United States G e o l o g i c a l Survey, P e n n s y l v a n i a Cooperative Fish and Wildlife Research Unit, University Park PA USA 3. TSE/Prion Biochemistry Section, Rocky Mountain Laboratories, National Institutes of Health, Hamilton, MT USA 3. Department of MIP, Colorado State University, Fort Collins CO USA 4. National Park Service, Wildlife Health Branch, Fort Collins CO USA 5. Virus and Prion Research Unit, National Animal Disease Center, ARS, USDA, Ames IA USA 6. USDA, APHIS, VS, STAS, National Veterinary Service Laboratories, Ames IA USA 7. National and OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa ON Canada 8. National Wildlife Research Center Wildlife Services, APHIS, USDA, Fort Collins CO USA

 

Chronic wasting disease (CWD) is an e f f i c i e n t l y t r a n smi t t e d s p o n g i f o r m encephalopathy of cervids (e.g. deer, elk, and moose), and is the only known prion disease affecting both free-ranging wildlife and captive animals. The antemortem detection of CWD and other prion diseases has proven difficult, due in part to difficulties in identifying an appropriate peripheral tissue specimen and complications with conventional test sensitivity. At present, biopsies of the recto-

 

Prion2015 Program Guide 22

 

anal mucosal-associated lymphoid tissues (RAMALT) have shown promising sensitivity and are not impractical to collect in live animals. Nasal brush collections have likewise proven both sensitive and practical for identification of prion infections in humans. In this study, we evaluated both RAMALT and nasal brush collections by real time quaking-induced conversion (RT-QuIC), and compared our findings to RAMALT immu n o h i s t o c h emi s t r y a s we l l a s conventional postmortem evaluation of obex and retropharyngeal lymph node tissues from over 700 captive and free-ranging deer and elk in areas with endemic CWD. We correlated our results with various clinical findings, including pathological stage of infection as determined by obex scoring, PrP genotype, age, and sex. While the sensitivity of RAMALT RT-QuIC analyses exceeded that of RAMALT IHC (69-80% vs. >44%) and nasal brush collections (15-30%), the sensitivity of both biopsy and nasal brush analyses were dependent primarily on clinical stage of disease, although PrP genotype was also an important predictor of sample positivity. Our findings further demonstrate the potential and limitations of antemortem sample analyses by RT-QuIC in the identification and management of prion diseases.

 

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

 

P200 Clinical Stage of Infection is Critical in the Antemortem Diagnosis of Chronic Wasting Disease in Deer and Elk.

 

Chris Siepker1, Nicholas Haley1, W. David Walter2, Laura Hoon-Hanks7, Ryan Monello3, Jenny Powers3, Bruce Thomsen4, Justin Greenlee4, Aaron Lehmkuhl4, Gordon Mitchell5, Tracy Nichols6, Edward Hoover7, Juergen Richt1

 

1Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS, USA, 2United States G e o l o g i c a l Survey, P e n n s y l v a n i a Cooperative Fish & Wildlife Research Unit, Pennsylvania State University, University Park, PA 16802, USA, 3National Park Service, Wildlife Health Branch, Fort Collins, CO, USA, 4USDA, APHIS, VS, STAS, National Veterinary Service Laboratories, Ames, IA, USA, 5National and OIE Reference Laboratory for Scrapie and CWD Ottawa Laboratory Fallowfield Canadian Food Inspection Agency, Ottawa, ON, Canada, 6National Wildlife Research Center Wildlife Services APHIS, USDA, Fort Collins, CO, USA, 7Department of MIP, Colorado State University, Fort Collins, CO, USA

 

Chronic wasting disease (CWD) is an e f f i c i e n t l y t r a n smi t t e d s p o n g i f o r m encephalopathy of cervids (e.g. deer, elk, and moose), and is the only known prion disease affecting both free-ranging wildlife and captive animals. The antemortem detection of CWD and other prion diseases has proven difficult, due in part to difficulties in identifying an appropriate peripheral tissue specimen and complications with conventional test sensitivity. At present, biopsies of the rectoanal mucosal-associated lymphoid tissues (RAMALT) have shown promising sensitivity and are not impractical to collect in live animals. Nasal brush collections have likewise proven both sensitive and practical for identification of prion infections in humans. In this study, we evaluated both RAMALT and nasal brush collections by real time quaking-induced conversion (RT-QuIC), and compared our findings to RAMALT immu n o h i s t o c h emi s t r y a s we l l a s conventional postmortem evaluation of obex and retropharyngeal lymph node tissues from over 700 captive and free-ranging deer and elk in areas with endemic CWD. We correlated our results with various clinical findings, including pathological stage of infection as determined by obex scoring, PrP genotype, age, and sex. While the sensitivity of RAMALT RT-QuIC analyses exceeded that of RAMALT IHC (69-80% vs. >44%) and nasal brush collections (15-30%), the sensitivity of both biopsy and nasal brush analyses were dependent primarily on clinical stage of disease, although PrP genotype was also an important predictor of sample positivity. Our findings further demonstrate the potential and limitations of antemortem sample analyses by RT-QuIC in the identification and management of prion diseases.

 


 


 

Research Project: Mitigating the Risk of Transmission and Environmental Contamination of Transmissible Spongiform Encephalopathies Location: Animal Diseases Research

 

2015 Annual Report

 

1a.Objectives (from AD-416): Objective 1: Determine whether goats are a transmission reservoir for ovine scrapie by developing and validating diagnostic methods for detecting goat scrapie. Determine the genetic predisposition and transmission route(s) of goat scrapie.

 

Subobjective 1.1: Improve eradication efforts by developing improved methods for antemortem scrapie diagnosis.

 

Subobjective 1.2: Determine if placenta and milk from goats are potential sources of scrapie to sheep.

 

Objective 2: Develop methods to mitigate infectivity of soil-associated prions by screening soil microbes for potential candidates for bioremediation.

 

1b.Approach (from AD-416): Scrapie is a complex and rare disorder affecting outbred farm animals held under a wide variety of husbandry conditions and exposed to an agent for which the transmissible and pathogenic events remain largely unknown. The work described in the research plan is an extension of the previous highly productive studies by this research group, addressing the need for implementation of federal regulations based on the best available science, often in the face of relatively small sample numbers in the natural host. The work includes development of specific management and diagnostic tools and is presented as an integrated series of research objectives. This approach was selected over a hypothesis based approach. After consulting Glass and Hall, the group determined that the work presented in the following plan was best represented by goal statements rather than hypotheses because the work increases the density of data necessary for progress and for support of current and proposed federal regulations. This project addresses only scrapie, the TSE of sheep and goats. Chronic wasting disease (CWD) is the TSE of North America cervids (deer and elk). ***No live animal work with CWD is included in this project plan since CWD is not endemic in Washington State, the disease appears to be highly communicable, the modes of transmission are unknown, and we do not have suitable biocontainment facilities to conduct CWD studies in large animals.

 

3.Progress Report: The National Scrapie Eradication program in the U.S. is conducted by the state and federal animal disease health regulatory agencies, with research support by ARS and several land grant universities, in a joint endeavor with the sheep and goat industries. The comprehensive program of animal identification, surveillance and genetic selection has resulted in a decrease of scrapie prevalence by 88%. As prevalence falls, remaining potential sources of infection will be monitored. The transmissible spongiform encephalopathies (TSE) project at the Animal Disease Research Unit, Pullman, Washington, includes an integrated examination of modes of transmission (both intraspecies and interspecies), diagnostic test development and refinement, and delineation of species-specific and genetically controlled differences in pathogenesis. In FY15, progress was reported in each of these research areas.

 

Objective 1: Transmission of scrapie by placenta, blood and milk. Exposure of the newborn lamb or kid to infectious prions shed by the postparturient ewe/doe is probably the most efficient route of transmission in the field. Our earlier work demonstrated the role of fetal genotype on transmission by the ovine placenta. In this Fiscal Year (FY), we completed a study demonstrating that the caprine placenta, while containing sparse amounts of detectable PrP-Sc, is infectious to lambs and kids by oral exposure. Experimental oral exposure of lambs and kids to milk from infected does during the first 2 to 3 days of life was performed last year and the recipient animals are monitored for evidence of disease. With an incubation period of 24-36 months, the study is expected to yield useful information in FY16. These studies of experimental disease are complemented by ongoing observations on transmission in our mixed herd of infected goats and sheep.

 

Objective 2: Diagnosis and genetics of the TSEs in ruminant animals: Gold standard testing of scrapie is performed by immunohistochemistry of formalin fixed tissues, using lymphoid tissue to detect early disease and brain tissue to detect advanced disease. Antemortem tissue based testing requires expertise in the field and in the laboratory. We are completing a study examining the effects of host and biopsy handling on lymphoid follicle frequency and detection of PrP-Sc. Similarly, immunohistochemistry has been applied to determine the effects of these factors on the frequency of observing two major cell types known to accumulate PrPSc in lymphoid tissues—namely, macrophages and follicular dendritic cells. These studies will be completed in FY16 and will provide information on any needed refinements in the antemortem testing of sheep and goats, with possible application to the evolving program of live animal testing of captive deer and elk.

 

Genetic variation among animals within each species affects disease resistance and incubation time: We have previously reported the effect of genotype on diagnostic accuracy in white tailed deer. We have now completed a study examining the role of a prion gene polymorphism at residue 127 in goats on incubation time (reported in accomplishments) and in FY16 will perform studies on diagnostic accuracy of the current testing modes in goats with this genotype.

 

Polymorphisms at additional sites (146 and 222) have been reported to be associated with reduced susceptibility to caprine scrapie. Goat kids were exposed to scrapie by the oral route on day 1 of life and are being monitored. Goats with the potentially resistant allele have remained clinically normal for more than 7 years after oral challenge; control goats lacking this allele developed disease at 2-3 years of age. We will continue to monitor the 222K goats for their natural lifespan and will perform extensive necropsy examinations upon termination to determine whether these animals are a benefit to the industry or represent a long lived source of prions in goat herds. The polymorphism at residue 222, while potentially conferring resistance to scrapie, also presents a diagnostic challenge. Residue 222 is included in the epitope recognized by the monoclonal antibody used in gold standard diagnostic testing in the U.S. We have reported the effect of this polymorphism on test sensitivity (reported in accomplishments). We have previously reported that this polymorphism is rare in U.S. goats, but in the current work, we presented some alternatives to testing should this genotype be selected by breeders in the future.

 

Examination of the prion distribution in fixed tissues is the basis for diagnostic testing. In addition, the distribution and intensity of the immunohistochemical staining are also useful indirect measures of disease progression. We have reported this effect in our studies of genetics and diagnosis of chronic wasting disease in white tailed deer. We have now extended those studies to include Rocky Mountain elk, which have a unique prion distribution pattern. We continue to work with state and federal agencies monitoring the effects of genotype on prion disease captive and free-ranging Rocky Mountain elk, as components of species-specific control programs.

 

While antemortem and postmortem tissue-based testing is sensitive and specific, collection of tissues is inconvenient and testing is expensive. Development of a blood based test might alleviate those problems. We are conducting a systematic examination of prion-bearing cell types in sheep and goats and have reported that all three major types of peripheral blood mononuclear cells—B lymphocytes, T lymphocytes, and monocytes, can harbor prions and are thus reasonable targets on which to base development of a diagnostic platform for use during preclinical infection. We have recently reported that relatively small amounts of blood contain infectious prions and continue to examine methods for more sensitive and specific detection of PrP-Sc in circulating cells.

 

Objective 3: Introduction of disease by novel routes: While direct contact with prion-bearing tissues remains the most likely source of infection in sheep and goats, the introduction of disease through fomites or through contact with other species has not been ruled out. We originally intended to examine the role of soil or premise contamination with prions after removal of infected sheep. However, the success of the eradication program at reducing scrapie prevalence to nearly undetectable levels over a relatively short amount of time suggests that environmental routes are not highly efficient. ***However, prevalence of chronic wasting disease in farmed and free-ranging cervids continues to climb and as the disease is discovered in an increasing number of states and provinces, the threat of transmission to sheep remains under investigation. In conjunction with the Canadian Food Inspection Agency, we are completing a study delineating methods for discriminating between a TSE of ovine and cervid origin in sheep, using both conventional in vitro prion characterization methods and in vivo studies with a panel of transgenic mice. The study will be concluded in FY16; preliminary findings show differences in incubation time and molecular folding patterns that may be useful in determining the origin of TSEs of sheep in the CWD endemic zones.

 

In a continued effort to reduce research dependence on bioassay, work continued on the creation of cultured cell lines with robust permissiveness to natural isolates of prions. Work continued on the immortalization of caprine microglia cell lines with different prion genotypes of interest. Studies also continued in the optimization of the scrapie permissiveness of a caprine prion protein-transfected rabbit kidney epithelial cell line. Factors associated with cellular permissiveness to infection were also determined in a study that compared the transcriptomes of clones from an immortalized ovine microglia cell line but that differ greatly in permissiveness to natural source isolates (i.e., hindbrain) of classical scrapie prions.

 

4.Accomplishments 1. The placenta of goats with scrapie is infectious to goat kids and lambs. The placenta of sheep is a highly infectious source of scrapie prions and is well known to play a major role in natural transmission. Goats, too, are a natural host of classical scrapie and are frequently raised with sheep, but the potential routes of natural transmission from goats to sheep have not been studied. ARS researchers at the Animal Disease Research Unit in Pullman, Washington, have now demonstrated that the placenta shed from a goat, despite its relatively sparse accumulation of the disease-associated form of the prion protein, is infectious to newborn lambs and goat kids by oral exposure. This accomplishment provides a scientific basis for regulatory and veterinary consideration as to the possible modes of transmission risk of scrapie from goats to sheep.

 

2. Prions were detected in small volume blood samples obtained from sheep with preclinical scrapie. Initial studies that demonstrated the potential for developing a blood-based live animal diagnostic test for classical scrapie in sheep were based on blood sample volumes many times more than routinely used in the practice of veterinary medicine. ARS researchers at the Animal Disease Research Unit in Pullman, Washington, have now demonstrated that infectious prions can be detected from much smaller blood sample volumes, even during preclinical infection. This study supports further development of a safe and highly efficient blood-based diagnostic test for preclinical scrapie infection in sheep. It demonstrates the utility of using the small blood sample volumes already routinely collected for diagnostic purposes.

 

3. A prion gene polymorphism that prolongs scrapie incubation in goats. Scrapie eradication in sheep is based in part on strong genetic resistance to classical scrapie infection. However, knowledge regarding the implications of differing genotypes in goats is incomplete. ARS researchers at the Animal Disease Research Unit in Pullman, Washington, have now demonstrated that the appearance of clinical signs associated with scrapie can be significantly delayed in goats with a prion gene polymorphism at codon 127. This accomplishment helps explain why goats with this polymorphism may be underrepresented in surveys of scrapie infected goat herds. Additionally, this accomplishment suggests that scrapie eradication programs might need to include longer trace-back histories when investigating scrapie-exposed goats of this genotype.

 

4. A prion gene polymorphism that reduces the sensitivity of some diagnostic tests for caprine scrapie. Gold standard diagnostic testing for caprine scrapie is performed by monoclonal antibody immunohistochemistry. While this assay is highly specific, the sensitivity of the assay is limited by the use of a single monoclonal antibody directed to a variable portion of the prion molecule. ARS researchers at the Animal Disease Research Unit in Pullman, Washington, have confirmed that the monoclonal antibody currently used for testing in the U.S. fails to detect prions in goats homozygous for a prion polymorphism at codon 222. The study was performed by developing a digital image segmentation and analysis algorithm to objectively measure spatially diverse PrPSc accumulation profiles in the hindbrain of goats with naturally acquired classical scrapie. Comparisons were also made under the standardized conditions and reagents currently utilized by regulatory agencies. This accomplishment provides the scientific basis for modification of the assay should this prion genotype become more prevalent in the U.S. goat herd.

 

***5. Delineation of the progression of abnormal prion accumulation in the brain of elk with chronic wasting disease. Diagnostic testing for the transmissible spongiform encephalophathies (TSE) of elk is performed by examination of a single section of brain, using a monoclonal antibody that detects the abnormal prion protein. Collaborative research including scientists from the Colorado State University Diagnostic Laboratory, the U.S. Department of Agriculture Animal Health Inspection Service, the Canadian Food Inspection Agency, and the ARS Animal Disease Research Unit in Pullman, Washington, has demonstrated that the abnormal prion in this section of brain has a unique and relatively consistent pattern of accumulation as disease progresses. The study complements the earlier work performed by ARS and others on the effect of prion genotype on disease progression in elk and in white tailed deer. The scoring system described in these studies may be useful for estimating prion distribution throughout the infected animal and potentially for estimating the duration of infection, facilitating epidemiologic studies in infected herds.

 

Review Publications Schneider, D.A., Madsen-Bouterse, S.A., Zhuang, D., Truscott, T.C., Dassanayake, R.P., O'Rourke, K.I. 2015. The placenta shed from goats with classical scrapie is infectious to goat kids and lambs. Journal of General Virology. doi: 10.1099/vir.0.000151.

 

Munoz-Gutierrez, J.F., Schneider, D.A., Baszler, T.V., Dinkel, K.D., Greenlee, J.J., Nicholson, E.M., Stanton, J.J. 2015. hTERT-immortalized ovine microglia propagate natural scrapie isolates. Virus Research. 198:35-43.

 

Dassanayake, R.P., White, S.N., Madsen-Bouterse, S.A., Schneider, D.A., O'Rourke, K.I. 2015. Role of PRNP S127 allele in experimental goat infection with classical caprine scrapie. Animal Genetics. doi: 10.1111/age.12291.

 

Dassanayake, R.P., Truscott, T.C., Zhuang, D., Schneider, D.A., Madsen-Bouterse, S.A., Young, A.J., Stanton, J.B., Davis, W.C., O’Rourke, K.I. 2015. Classical natural ovine scrapie prions are detected in practical volumes of blood by lamb and transgenic mouse bioassay. Journal of Veterinary Science. 16(2):179-186.

 

Madsen-Bouterse, S.A., Schneider, D.A., Dassanayake, R.P., Truscott, T.C., Zhuang, D., Kumpula-Mcwhirter, N., O'Rourke, K.I. 2015. PRNP variants in goats reduce sensitivity of detection of PrPSc by immunoassay. Journal of Veterinary Diagnostic Investigation. 27(3):332-343.

 

Spraker, T.R., Gidlewski, T., Powers, J.G., Nichols, T., Balachandran, .A., Cummins, B., Wild, M.A., Vercauteren, K., O'Rourke, K. 2015. Progressive accumulation of the abnormal conformer of the prion protein and spongiform encephalopathy in the obex of nonsymptomatic and symptomatic Rocky Mountain elk (Cervus elaphus nelsoni) with chronic wasting disease. Journal of Veterinary Diagnostic Investigation. doi: 10.117/1040638715593368.

 


 

Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES Title: Antemortem detection of chronic wasting disease prions in nasal brush collections and rectal biopsies from white-tailed deer by real time quaking-induced conversion

 

Authors

 

item Haley, Nicholas - item Siepker, Chris - item Walter, W. David - item Thomsen, Bruce - item Greenlee, Justin item Lehmkuhl, Aaron - item Richt, Jürgen -

 

Submitted to: Journal of Clinical Microbiology Publication Type: Peer Reviewed Journal Publication Acceptance Date: November 27, 2015 Publication Date: N/A

 

Interpretive Summary: Chronic Wasting Disease (CWD), a fatal neurodegenerative disease that occurs in farmed and wild cervids (deer and elk) of North America, is a transmissible spongiform encephalopathy (TSE). TSEs are caused by infectious proteins called prions that are resistant to various methods of decontamination and environmental degradation. Early diagnosis of CWD in wild and captive herds would be very helpful to controlling the spread of CWD, for which there are not yet any preventative or treatment measures available. The purpose of this study was to test a laboratory method of prion detection (real-time Quaking Induced Conversion; RT-QuIC) that has the potential to detect very low levels of infectious prions in samples collected from live animals against the gold standard diagnostic where abnormal prion in tissues is stained on a microscope slide. This study reports that RT-QuIC detects more cases of CWD than standard methods, but also can identify a small number of animals without CWD as being positive. In the case of CWD, where it is likely that large numbers of animals within a herd may be positive, misidentifying a negative as a positive may have less of an impact than in the case of other prion diseases such as bovine spongiform encephalopathy considering that this test allows testing much larger numbers of samples with a faster turn around time than traditional methods. This information could have an impact on regulatory and wildlife officials developing plans to reduce or eliminate CWD and cervid farmers that want to ensure that their herd remains CWD-free. Technical Abstract: Chronic wasting disease (CWD), a transmissible spongiform encephalopathy of cervids, was first documented nearly fifty years ago in Colorado and Wyoming and has since spread to cervids in 23 states, 2 Canadian provinces, and the Republic of Korea. The increasing expansion of this disease makes the development of sensitive diagnostic assays and antemortem sampling techniques crucial for the mitigation of spread; this is especially true in cases of relocation/reintroduction of farmed or free-ranging deer and elk, or surveillance studies in private or protected herds where depopulation may be contraindicated. This study sought to evaluate the sensitivity of the real-time quaking-induced conversion (RT-QuIC) assay in samples collected antemortem. Antemortem findings were then compared to results from ante- and postmortem samples evaluated using the current gold standard diagnostic assay, immunohistochemistry (IHC). Recto-anal mucosal associated lymphoid tissue (RAMALT) biopsies and nasal brush collections from three separate herds of farmed white-tailed deer (n=409) were evaluated, along with standard postmortem microscopic analysis of brainstem at the level of the obex and retropharyngeal lymph nodes. We hypothesized the sensitivity of RT-QuIC would be comparable to IHC in antemortem tissues, and would correlate with both genotype and stage of clinical disease. ***Our results showed that RAMALT testing by RT-QuIC had the highest sensitivity (69.8%) when compared to postmortem testing. This data suggests that RT-QuIC, like IHC, is a fairly sensitive assay for detection of CWD prions in rectal biopsies and other antemortem samples, and with further investigation has potential for large scale and rapid automated testing for CWD diagnosis.

 


 

Research Project: Transmission, Differentiation, and Pathobiology of Transmissible Spongiform Encephalopathies 2015 Annual Report

 

1a.Objectives (from AD-416): 1. Investigate the pathobiology of atypical transmissible spongiform encephalopathies (TSEs) in natural hosts. A. Investigate the pathobiology of atypical scrapie. B. Investigate the pathobiology of atypical bovine spongiform encephalopathy (BSE). 2. Investigate the horizontal transmission of TSEs. A. Assess the horizontal transmission of sheep scrapie in the absence of lambing. B. Determine routes of transmission in chronic wasting disease (CWD) infected premises. C. Assess oral transmission of CWD in reindeer. 3. Investigate determinants of CWD persistence. A. Determine CWD host range using natural routes of transmission. B. Investigate the pathobiology of CWD.

 

1b.Approach (from AD-416): The studies will focus on three animal transmissible spongiform encephalopathy (TSE) agents found in the United States: bovine spongiform encephalopathy (BSE); scrapie of sheep and goats; and chronic wasting disease (CWD) of deer, elk, and moose. The research will address sites of accumulation, routes of infection, environmental persistence, and ante mortem diagnostics with an emphasis on controlled conditions and natural routes of infection. Techniques used will include clinical exams, histopathology, immunohistochemistry and biochemical analysis of proteins. The enhanced knowledge gained from this work will help mitigate the potential for unrecognized epidemic expansions of these diseases in populations of animals that could either directly or indirectly affect food animals.

 

3.Progress Report: Research efforts directed toward meeting objective 1 of our project plan include work in previous years starting with the inoculation of animals for studies designed to address the pathobiology of atypical scrapie, atypical bovine spongiform encephalopathy (BSE), as well as a genetic version of BSE. Post-mortem examination of the animals inoculated with atypical scrapie has been initiated and laboratory analysis of the tissues is ongoing. Atypical BSE animals have developed disease and evaluation of the samples is currently underway. Animals inoculated with a genetic version of BSE have developed disease with a manuscript reporting these results was published (2012), and additional laboratory comparisons of genetic BSE to atypical and classical BSE are ongoing. In addition, we have investigated the possibility that atypical scrapie was present earlier than previously detected in the national flock by analyzing archived field isolates using methods that were unavailable at the time of original diagnosis. Sample quality was sufficiently degraded that modern methods, beyond those applied to the tissues at the time the tissues were archived, were not suitable for evaluation. In research pertaining to objective 2, "Investigate the horizontal transmission of TSEs", we have initiated a study to determine if cohousing non-lambing scrapie inoculated sheep is sufficient to transmit scrapie to neonatal lambs. At this time, scrapie free ewes have lambed in the presence of scrapie inoculated animals and the lambs are cohoused with these inoculated animals.

 

4.Accomplishments 1. Changes in retinal function in cattle can be used to identify different types of bovine spongiform encephalopathy (BSE). BSE belongs to a group of fatal, transmissible protein misfolding diseases known as transmissible spongiform encephalopathies (TSEs). Like other protein misfolding diseases including Parkinson's disease and Alzheimer's disease, TSEs are generally not diagnosed until the onset of disease after the appearance of unequivocal clinical signs. As such, identification of the earliest clinical signs of disease may facilitate diagnosis. The retina is the most accessible part of the central nervous system. ARS scientist in Ames IA described antemortem changes in retinal function and thickness that are detectable in BSE inoculated animals up to 11 months prior to the appearance of any other signs of clinical disease. Differences in the severity of these clinical signs reflect the amount of PrPSc accumulation in the retina and the resulting inflammatory response of the tissue. These results are the earliest reported clinical signs associated with TSE infection and provide a basis for understanding the pathology and evaluating therapeutic interventions. Further, this work shows that High-type BSE and classical BSE can be differentiated by eye examination alone, the first time BSE strains have been differentiable in a live animal.

 

2. Sheep genetics influences the susceptibility of sheep to scrapie. Sheep scrapie is a transmissible spongiform encephalopathy that can be transmitted between affected animals resulting in significant economic losses in affected flocks. The prion protein gene (PRNP) profoundly influences the susceptibility of sheep to the scrapie agent and the tissue levels and distribution of PrPSc in affected sheep. In this study, sheep of 3 different prion genetic types (denoted VRQ/VRQ, VRQ/ARR and ARQ/ARR) were inoculated and subsequently euthanized upon onset of disease. Disease aspects were uniform across genotypes and consistent with manifestations of classical scrapie. Mean survival time differences were associated with the genetic type such that VRQ/VRQ sheep survived 18 months, whereas VRQ/ARR and ARQ/ARR sheep survived 60 and 56 months, respectively. Microscopic evaluation revealed similar accumulations in central nervous system tissues regardless of host genetic type. PrPSc in lymphoid tissue was consistently abundant in VRQ/VRQ, present but confined to tonsil or retropharyngeal lymph node in 4/5 VRQ/ARR, and totally absent in ARQ/ARR sheep. The results of this study demonstrate the susceptibility of sheep with the ARQ/ARR genotype to scrapie by the intracranial inoculation route with PrPSc accumulation in CNS tissues, but prolonged incubation times and lack of PrPSc in lymphoid tissue. These results are important for science based policy with regard to testing of sheep for scrapie where some live animal testing is conducted using lymphoid tissues which would not detect scrapie in some specific genetic types which could limit the national scrapie eradication program.

 

Review Publications Greenlee J.J. 2014. The prion diseases of animals. In: McManus, L.M., Mitchell, R.N., editors. Pathobiology of Human Disease. San Diego: Elsevier. p. 1124-1133.

 

Greenlee, J.J., Kunkle, R.A., Richt, J.A., Nicholson, E.M., Hamir, A.N. 2014. Lack of prion accumulation in lymphoid tissues of PRNP ARQ/ARR sheep intracranially inoculated with the agent of scrapie. PLoS One. 9(9):e108029.

 

Greenlee, J.J., West Greenlee, M.,H. 2015. The transmissible spongiform encephalopathies of livestock. ILAR Journal. 56(1):7-25.

 

Munoz-Gutierrez, J.F., Schneider, D.A., Baszler, T.V., Dinkel, K.D., Greenlee, J.J., Nicholson, E.M., Stanton, J.J. 2015. hTERT-immortalized ovine microglia propagate natural scrapie isolates. Virus Research. 198:35-43.

 

Nicholson, E.M. 2015. Detection of the disease-associated form of the prion protein in biological samples. Bioanalysis. 7(2):253-261.

 

West Greenlee, M.H., Smith, J.D., Platt, E.M., Juarez, J.R., Timms, L.L, Greenlee, J.J. 2015. Changes in retinal function and morphology are early clinical signs of disease in cattle with bovine spongiform encephalopathy. PLoS ONE. 10(3):e0119431.

 

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.

 


 

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

 

***Title: Transmission of chronic wasting disease to sentinel reindeer (Rangifer tarandus tarandus)

 

Authors

 

item Moore, S - item Kunkle, Robert item Nicholson, Eric item Richt, Juergen item Hamir, Amirali item Waters, Wade item Greenlee, Justin

 

Submitted to: American College of Veterinary Pathologists Meeting Publication Type: Abstract Only Publication Acceptance Date: August 12, 2015 Publication Date: N/A

 

Technical Abstract:

 

Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of North American cervids. Reindeer (Rangifer tarandus tarandus) are susceptible to CWD following oral challenge, but CWD has not been reported in free-ranging caribou (Rangifer tarandus caribou) or farmed reindeer. Potential contact between CWD-affected cervids and Rangifer species that are free-ranging or co-housed on farms presents a potential risk of CWD transmission. The aims of this study were to 1) investigate the transmission of CWD from white-tailed deer (Odocoileus virginianus; CWD-wtd), mule deer (Odocoileus hemionus; CWD-md), or elk (Cervus elaphus nelsoni; CWD-elk) to reindeer via the intracranial route, and 2) to assess for direct and indirect horizontal transmission to non-inoculated sentinels. Three groups of 5 reindeer fawns were challenged intracranially with CWD-wtd, CWD-md, or CWD-elk. Two years after challenge of inoculated reindeer, non-inoculated control reindeer were introduced into the same pen as the CWD-wtd inoculated reindeer (n=4) or into a pen adjacent to the CWD-md inoculated reindeer (n=2). Reindeer were allowed to develop clinical disease. At death/euthanasia a complete necropsy examination was performed, including immunohistochemical testing of tissues for disease-associated CWD prion protein (PrP-CWD). Intracranially challenged reindeer developed clinical disease from 21 months post-inoculation (MPI). PrP-CWD was detected in 5/6 sentinel reindeer although only 2/6 developed clinical disease during the study period (<57 div="" mpi="">

 

***We have shown that reindeer are susceptible to CWD from various cervid sources and can transmit CWD to naive reindeer both directly and indirectly.

 

Last Modified: 12/3/2015

 


 

***PrP-CWD was detected in 5/6 sentinel reindeer although only 2/6 developed clinical disease during the study period (<57 div="" mpi="">

 

***We have shown that reindeer are susceptible to CWD from various cervid sources and can transmit CWD to naive reindeer both directly and indirectly.

 

Tuesday, September 29, 2015

 

*** Transmission of chronic wasting disease to sentinel reindeer (Rangifer tarandus tarandus) can transmit CWD to naive reindeer both directly and indirectly

 

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

 


 

*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years ***

 

Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3

 


 

*** Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.

 


 

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.

 


 

Friday, December 14, 2012

 

DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012

 

snip...

 

In the USA, under the Food and Drug Administration’s BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law.

 

Animals considered at high risk for CWD include:

 

1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and

 

2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.

 

Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.

 

The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES. It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.

 

Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.

 

There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.

 

snip...

 

36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011). The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE). Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison.

 

snip...

 

The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).

 

snip...

 

In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion.

 

snip...

 

In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible. For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.

 

snip...

 

Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.

 

snip...

 


 

Saturday, January 31, 2015

 

European red deer (Cervus elaphus elaphus) are susceptible to Bovine Spongiform Encephalopathy BSE by Oral Alimentary route

 


 

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 soon as possible for the following reasons...

 

======

 

In the USA, under the Food and Drug Administrations 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.

 

======

 

31 Jan 2015 at 20:14 GMT

 

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

 

31 Jan 2015 at 20:14 GMT

 


 

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 ;

 


 

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 ;

 


 


 


 


 


 

98 | Veterinary Record | January 24, 2015

 

EDITORIAL

 

Scrapie: a particularly persistent pathogen

 

Cristina Acín

 

Resistant prions in the environment have been the sword of Damocles for scrapie control and eradication. Attempts to establish which physical and chemical agents could be applied to inactivate or moderate scrapie infectivity were initiated in the 1960s and 1970s,with the first study of this type focusing on the effect of heat treatment in reducing prion infectivity (Hunter and Millson 1964). Nowadays, most of the chemical procedures that aim to inactivate the prion protein are based on the method developed by Kimberlin and collaborators (1983). This procedure consists of treatment with 20,000 parts per million free chlorine solution, for a minimum of one hour, of all surfaces that need to be sterilised (in laboratories, lambing pens, slaughterhouses, and so on). Despite this, veterinarians and farmers may still ask a range of questions, such as ‘Is there an official procedure published somewhere?’ and ‘Is there an international organisation which recommends and defines the exact method of scrapie decontamination that must be applied?’

 

From a European perspective, it is difficult to find a treatment that could be applied, especially in relation to the disinfection of surfaces in lambing pens of affected flocks. A 999/2001 EU regulation on controlling spongiform encephalopathies (European Parliament and Council 2001) did not specify a particular decontamination measure to be used when an outbreak of scrapie is diagnosed. There is only a brief recommendation in Annex VII concerning the control and eradication of transmissible spongiform encephalopathies (TSE s).

 

Chapter B of the regulation explains the measures that must be applied if new caprine animals are to be introduced to a holding where a scrapie outbreak has previously been diagnosed. In that case, the statement indicates that caprine animals can be introduced ‘provided that a cleaning and disinfection of all animal housing on the premises has been carried out following destocking’.

 

Issues around cleaning and disinfection are common in prion prevention recommendations, but relevant authorities, veterinarians and farmers may have difficulties in finding the specific protocol which applies. The European Food and Safety Authority (EFSA ) published a detailed report about the efficacy of certain biocides, such as sodium hydroxide, sodium hypochlorite, guanidine and even a formulation of copper or iron metal ions in combination with hydrogen peroxide, against prions (EFSA 2009). The report was based on scientific evidence (Fichet and others 2004, Lemmer and others 2004, Gao and others 2006, Solassol and others 2006) but unfortunately the decontamination measures were not assessed under outbreak conditions.

 

The EFSA Panel on Biological Hazards recently published its conclusions on the scrapie situation in the EU after 10 years of monitoring and control of the disease in sheep and goats (EFSA 2014), and one of the most interesting findings was the Icelandic experience regarding the effect of disinfection in scrapie control. The Icelandic plan consisted of: culling scrapie-affected sheep or the whole flock in newly diagnosed outbreaks; deep cleaning and disinfection of stables, sheds, barns and equipment with high pressure washing followed by cleaning with 500 parts per million of hypochlorite; drying and treatment with 300 ppm of iodophor; and restocking was not permitted for at least two years. Even when all of these measures were implemented, scrapie recurred on several farms, indicating that the infectious agent survived for years in the environment, even as many as 16 years after restocking (Georgsson and others 2006).

 

In the rest of the countries considered in the EFSA (2014) report, recommendations for disinfection measures were not specifically defined at the government level. In the report, the only recommendation that is made for sheep is repopulation with sheep with scrapie-resistant genotypes. This reduces the risk of scrapie recurrence but it is difficult to know its effect on the infection.

 

Until the EFSA was established (in May 2003), scientific opinions about TSE s were provided by the Scientific Steering Committee (SSC) of the EC, whose advice regarding inactivation procedures focused on treating animal waste at high temperatures (150°C for three hours) and high pressure alkaline hydrolysis (SSC 2003). At the same time, the TSE Risk Management Subgroup of the Advisory Committee on Dangerous Pathogens (ACDP) in the UK published guidance on safe working and the prevention of TSE infection. Annex C of the ACDP report established that sodium hypochlorite was considered to be effective, but only if 20,000 ppm of available chlorine was present for at least one hour, which has practical limitations such as the release of chlorine gas, corrosion, incompatibility with formaldehyde, alcohols and acids, rapid inactivation of its active chemicals and the stability of dilutions (ACDP 2009).

 

In an international context, the World Organisation for Animal Health (OIE) does not recommend a specific disinfection protocol for prion agents in its Terrestrial Code or Manual. Chapter 4.13 of the Terrestrial Code, General recommendations on disinfection and disinsection (OIE 2014), focuses on foot-and-mouth disease virus, mycobacteria and Bacillus anthracis, but not on prion disinfection. Nevertheless, the last update published by the OIE on bovine spongiform encephalopathy (OIE 2012) indicates that few effective decontamination techniques are available to inactivate the agent on surfaces, and recommends the removal of all organic material and the use of sodium hydroxide, or a sodium hypochlorite solution containing 2 per cent available chlorine, for more than one hour at 20ºC.

 

The World Health Organization outlines guidelines for the control of TSE s, and also emphasises the importance of mechanically cleaning surfaces before disinfection with sodium hydroxide or sodium hypochlorite for one hour (WHO 1999).

 

Finally, the relevant agencies in both Canada and the USA suggest that the best treatments for surfaces potentially contaminated with prions are sodium hydroxide or sodium hypochlorite at 20,000 ppm. This is a 2 per cent solution, while most commercial household bleaches contain 5.25 per cent sodium hypochlorite. It is therefore recommended to dilute one part 5.25 per cent bleach with 1.5 parts water (CDC 2009, Canadian Food Inspection Agency 2013).

 

So what should we do about disinfection against prions? First, it is suggested that a single protocol be created by international authorities to homogenise inactivation procedures and enable their application in all scrapie-affected countries. Sodium hypochlorite with 20,000 ppm of available chlorine seems to be the procedure used in most countries, as noted in a paper summarised on p 99 of this issue of Veterinary Record (Hawkins and others 2015). But are we totally sure of its effectiveness as a preventive measure in a scrapie outbreak? Would an in-depth study of the recurrence of scrapie disease be needed?

 

What we can conclude is that, if we want to fight prion diseases, and specifically classical scrapie, we must focus on the accuracy of diagnosis, monitoring and surveillance; appropriate animal identification and control of movements; and, in the end, have homogeneous and suitable protocols to decontaminate and disinfect lambing barns, sheds and equipment available to veterinarians and farmers. Finally, further investigations into the resistance of prion proteins in the diversity of environmental surfaces are required.

 

References

 

snip...

 

98 | Veterinary Record | January 24, 2015

 


 

Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination

 

Steve A. C. Hawkins, MIBiol, Pathology Department1, Hugh A. Simmons, BVSc MRCVS, MBA, MA Animal Services Unit1, Kevin C. Gough, BSc, PhD2 and Ben C. Maddison, BSc, PhD3 + Author Affiliations

 

1Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK 2School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK 3ADAS UK, School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK E-mail for correspondence: ben.maddison@adas.co.uk Abstract Scrapie of sheep/goats and chronic wasting disease of deer/elk are contagious prion diseases where environmental reservoirs are directly implicated in the transmission of disease. In this study, the effectiveness of recommended scrapie farm decontamination regimens was evaluated by a sheep bioassay using buildings naturally contaminated with scrapie. Pens within a farm building were treated with either 20,000 parts per million free chorine solution for one hour or were treated with the same but were followed by painting and full re-galvanisation or replacement of metalwork within the pen. Scrapie susceptible lambs of the PRNP genotype VRQ/VRQ were reared within these pens and their scrapie status was monitored by recto-anal mucosa-associated lymphoid tissue. All animals became infected over an 18-month period, even in the pen that had been subject to the most stringent decontamination process. These data suggest that recommended current guidelines for the decontamination of farm buildings following outbreaks of scrapie do little to reduce the titre of infectious scrapie material and that environmental recontamination could also be an issue associated with these premises.

 

SNIP...

 

Discussion

 

Thorough pressure washing of a pen had no effect on the amount of bioavailable scrapie infectivity (pen B). The routine removal of prions from surfaces within a laboratory setting is treatment for a minimum of one hour with 20,000 ppm free chlorine, a method originally based on the use of brain macerates from infected rodents to evaluate the effectiveness of decontamination (Kimberlin and others 1983). Further studies have also investigated the effectiveness of hypochlorite disinfection of metal surfaces to simulate the decontamination of surgical devices within a hospital setting. Such treatments with hypochlorite solution were able to reduce infectivity by 5.5 logs to lower than the sensitivity of the bioassay used (Lemmer and others 2004). Analogous treatment of the pen surfaces did not effectively remove the levels of scrapie infectivity over that of the control pens, indicating that this method of decontamination is not effective within a farm setting. This may be due to the high level of biological matrix that is present upon surfaces within the farm environment, which may reduce the amount of free chlorine available to inactivate any infectious prion. Remarkably 1/5 sheep introduced into pen D had also became scrapie positive within nine months, with all animals in this pen being RAMALT positive by 18 months of age. Pen D was no further away from the control pen (pen A) than any of the other pens within this barn. Localised hot spots of infectivity may be present within scrapie-contaminated environments, but it is unlikely that pen D area had an amount of scrapie contamination that was significantly different than the other areas within this building. Similarly, there were no differences in how the biosecurity of pen D was maintained, or how this pen was ventilated compared with the other pens. This observation, perhaps, indicates the slower kinetics of disease uptake within this pen and is consistent with a more thorough prion removal and recontamination. These observations may also account for the presence of inadvertent scrapie cases within other studies, where despite stringent biosecurity, control animals have become scrapie positive during challenge studies using barns that also housed scrapie-affected animals (Ryder and others 2009). The bioassay data indicate that the exposure of the sheep to a farm environment after decontamination efforts thought to be effective in removing scrapie is sufficient for the animals to become infected with scrapie. The main exposure routes within this scenario are likely to be via the oral route, during feeding and drinking, and respiratory and conjunctival routes. It has been demonstrated that scrapie infectivity can be efficiently transmitted via the nasal route in sheep (Hamir and others 2008), as is the case for CWD in both murine models and in white-tailed deer (Denkers and others 2010, 2013). Recently, it has also been demonstrated that CWD prions presented as dust when bound to the soil mineral montmorillonite can be infectious via the nasal route (Nichols and others 2013). When considering pens C and D, the actual source of the infectious agent in the pens is not known, it is possible that biologically relevant levels of prion survive on surfaces during the decontamination regimen (pen C). With the use of galvanising and painting (pen D) covering and sealing the surface of the pen, it is possible that scrapie material recontaminated the pens by the movement of infectious prions contained within dusts originating from other parts of the barn that were not decontaminated or from other areas of the farm.

 

Given that scrapie prions are widespread on the surfaces of affected farms (Maddison and others 2010a), irrespective of the source of the infectious prions in the pens, this study clearly highlights the difficulties that are faced with the effective removal of environmentally associated scrapie infectivity. This is likely to be paralleled in CWD which shows strong similarities to scrapie in terms of both the dissemination of prions into the environment and the facile mode of disease transmission. These data further contribute to the understanding that prion diseases can be highly transmissible between susceptible individuals not just by direct contact but through highly stable environmental reservoirs that are refractory to decontamination.

 

The presence of these environmentally associated prions in farm buildings make the control of these diseases a considerable challenge, especially in animal species such as goats where there is lack of genetic resistance to scrapie and, therefore, no scope to re-stock farms with animals that are resistant to scrapie.

 

Scrapie Sheep Goats Transmissible spongiform encephalopathies (TSE) Accepted October 12, 2014. Published Online First 31 October 2014

 


 

Monday, November 3, 2014

 

Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination

 


 

PPo3-22:

 

Detection of Environmentally Associated PrPSc on a Farm with Endemic Scrapie

 

Ben C. Maddison,1 Claire A. Baker,1 Helen C. Rees,1 Linda A. Terry,2 Leigh Thorne,2 Susan J. Belworthy2 and Kevin C. Gough3 1ADAS-UK LTD; Department of Biology; University of Leicester; Leicester, UK; 2Veterinary Laboratories Agency; Surry, KT UK; 3Department of Veterinary Medicine and Science; University of Nottingham; Sutton Bonington, Loughborough UK

 

Key words: scrapie, evironmental persistence, sPMCA

 

Ovine scrapie shows considerable horizontal transmission, yet the routes of transmission and specifically the role of fomites in transmission remain poorly defined. Here we present biochemical data demonstrating that on a scrapie-affected sheep farm, scrapie prion contamination is widespread. It was anticipated at the outset that if prions contaminate the environment that they would be there at extremely low levels, as such the most sensitive method available for the detection of PrPSc, serial Protein Misfolding Cyclic Amplification (sPMCA), was used in this study. We investigated the distribution of environmental scrapie prions by applying ovine sPMCA to samples taken from a range of surfaces that were accessible to animals and could be collected by use of a wetted foam swab. Prion was amplified by sPMCA from a number of these environmental swab samples including those taken from metal, plastic and wooden surfaces, both in the indoor and outdoor environment. At the time of sampling there had been no sheep contact with these areas for at least 20 days prior to sampling indicating that prions persist for at least this duration in the environment. These data implicate inanimate objects as environmental reservoirs of prion infectivity which are likely to contribute to disease transmission.

 


 

HIGHEST INFECTION RATE ON SEVERAL CWD CONFIRMED CAPTIVES

 

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)

 


 

”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.

 


 

Sunday, January 06, 2013

 

USDA TO PGC ONCE CAPTIVES ESCAPE

 

*** "it‘s no longer its business.”

 


 

CWD, spreading it around...

 

for the game farm industry, and their constituents, to continue to believe that they are _NOT_, and or insinuate that they have _NEVER_ been part of the problem, will only continue to help spread cwd. the game farming industry, from the shooting pens, to the urine mills, the antler mills, the sperm mills, velvet mills, shooting pens, to large ranches, are not the only problem, but it is painfully obvious that they have been part of the problem for decades and decades, just spreading it around, as with transportation and or exportation and or importation of cervids from game farming industry, and have been proven to spread cwd. no one need to look any further than South Korea blunder ;

 

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

 

spreading cwd around...

 

Between 1996 and 2002, chronic wasting disease was diagnosed in 39 herds of farmed elk in Saskatchewan in a single epidemic. All of these herds were depopulated as part of the Canadian Food Inspection Agency’s (CFIA) disease eradication program. Animals, primarily over 12 mo of age, were tested for the presence CWD prions following euthanasia. Twenty-one of the herds were linked through movements of live animals with latent CWD from a single infected source herd in Saskatchewan, 17 through movements of animals from 7 of the secondarily infected herds.

 

***The source herd is believed to have become infected via importation of animals from a game farm in South Dakota where CWD was subsequently diagnosed (7,4). A wide range in herd prevalence of CWD at the time of herd depopulation of these herds was observed. Within-herd transmission was observed on some farms, while the disease remained confined to the introduced animals on other farms.

 


 

spreading cwd around...

 

Friday, May 13, 2011

 

Chronic Wasting Disease (CWD) outbreaks and surveillance program in the Republic of Korea

 

Hyun-Joo Sohn, Yoon-Hee Lee, Min-jeong Kim, Eun-Im Yun, Hyo-Jin Kim, Won-Yong Lee, Dong-Seob Tark, In- Soo Cho, Foreign Animal Disease Research Division, National Veterinary Research and Quarantine Service, Republic of Korea

 

Chronic wasting disease (CWD) has been recognized as an important prion disease in native North America deer and Rocky mountain elks. The disease is a unique member of the transmissible spongiform encephalopathies (TSEs), which naturally affects only a few species. CWD had been limited to USA and Canada until 2000.

 

On 28 December 2000, information from the Canadian government showed that a total of 95 elk had been exported from farms with CWD to Korea. These consisted of 23 elk in 1994 originating from the so-called “source farm” in Canada, and 72 elk in 1997, which had been held in pre export quarantine at the “source farm”.Based on export information of CWD suspected elk from Canada to Korea, CWD surveillance program was initiated by the Ministry of Agriculture and Forestry (MAF) in 2001.

 

All elks imported in 1997 were traced back, however elks imported in 1994 were impossible to identify. CWD control measures included stamping out of all animals in the affected farm, and thorough cleaning and disinfection of the premises. In addition, nationwide clinical surveillance of Korean native cervids, and improved measures to ensure reporting of CWD suspect cases were implemented.

 

Total of 9 elks were found to be affected. CWD was designated as a notifiable disease under the Act for Prevention of Livestock Epidemics in 2002.

 

Additional CWD cases - 12 elks and 2 elks - were diagnosed in 2004 and 2005.

 

Since February of 2005, when slaughtered elks were found to be positive, all slaughtered cervid for human consumption at abattoirs were designated as target of the CWD surveillance program. Currently, CWD laboratory testing is only conducted by National Reference Laboratory on CWD, which is the Foreign Animal Disease Division (FADD) of National Veterinary Research and Quarantine Service (NVRQS).

 

In July 2010, one out of 3 elks from Farm 1 which were slaughtered for the human consumption was confirmed as positive. Consequently, all cervid – 54 elks, 41 Sika deer and 5 Albino deer – were culled and one elk was found to be positive. Epidemiological investigations were conducted by Veterinary Epidemiology Division (VED) of NVRQS in collaboration with provincial veterinary services.

 

Epidemiologically related farms were found as 3 farms and all cervid at these farms were culled and subjected to CWD diagnosis. Three elks and 5 crossbreeds (Red deer and Sika deer) were confirmed as positive at farm 2.

 

All cervids at Farm 3 and Farm 4 – 15 elks and 47 elks – were culled and confirmed as negative.

 

Further epidemiological investigations showed that these CWD outbreaks were linked to the importation of elks from Canada in 1994 based on circumstantial evidences.

 

In December 2010, one elk was confirmed as positive at Farm 5. Consequently, all cervid – 3 elks, 11 Manchurian Sika deer and 20 Sika deer – were culled and one Manchurian Sika deer and seven Sika deer were found to be positive. This is the first report of CWD in these sub-species of deer. Epidemiological investigations found that the owner of the Farm 2 in CWD outbreaks in July 2010 had co-owned the Farm 5.

 

In addition, it was newly revealed that one positive elk was introduced from Farm 6 of Jinju-si Gyeongsang Namdo. All cervid – 19 elks, 15 crossbreed (species unknown) and 64 Sika deer – of Farm 6 were culled, but all confirmed as negative.

 


 


 


 


 

New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication

 

The infectious agents responsible for transmissible spongiform encephalopathy (TSE) are notoriously resistant to most physical and chemical methods used for inactivating pathogens, including heat. It has long been recognized, for example, that boiling is ineffective and that higher temperatures are most efficient when combined with steam under pressure (i.e., autoclaving). As a means of decontamination, dry heat is used only at the extremely high temperatures achieved during incineration, usually in excess of 600°C. It has been assumed, without proof, that incineration totally inactivates the agents of TSE, whether of human or animal origin.

 


 

Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production

 

Histochemical analysis of hamster brains inoculated with the solid residue showed typical spongiform degeneration and vacuolation. Re-inoculation of these brains into a new cohort of hamsters led to onset of clinical scrapie symptoms within 75 days, suggesting that the specific infectivity of the prion protein was not changed during the biodiesel process. The biodiesel reaction cannot be considered a viable prion decontamination method for MBM, although we observed increased survival time of hamsters and reduced infectivity greater than 6 log orders in the solid MBM residue. Furthermore, results from our study compare for the first time prion detection by Western Blot versus an infectivity bioassay for analysis of biodiesel reaction products. We could show that biochemical analysis alone is insufficient for detection of prion infectivity after a biodiesel process.

 


 

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

 

The data presented here demonstrate that sPMCA can detect low levels of PrPCWD in the environment, corroborate previous biological and experimental data suggesting long term persistence of prions in the environment2,3 and imply that PrPCWD accumulation over time may contribute to transmission of CWD in areas where it has been endemic for decades. This work demonstrates the utility of sPMCA to evaluate other environmental water sources for PrPCWD, including smaller bodies of water such as vernal pools and wallows, where large numbers of cervids congregate and into which prions from infected animals may be shed and concentrated to infectious levels.

 


 

A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing

 

Keywords:Abattoir;bovine spongiform encephalopathy;QRA;scrapie;TSE

 

In this article the development and parameterization of a quantitative assessment is described that estimates the amount of TSE infectivity that is present in a whole animal carcass (bovine spongiform encephalopathy [BSE] for cattle and classical/atypical scrapie for sheep and lambs) and the amounts that subsequently fall to the floor during processing at facilities that handle specified risk material (SRM). BSE in cattle was found to contain the most oral doses, with a mean of 9864 BO ID50s (310, 38840) in a whole carcass compared to a mean of 1851 OO ID50s (600, 4070) and 614 OO ID50s (155, 1509) for a sheep infected with classical and atypical scrapie, respectively. Lambs contained the least infectivity with a mean of 251 OO ID50s (83, 548) for classical scrapie and 1 OO ID50s (0.2, 2) for atypical scrapie. The highest amounts of infectivity falling to the floor and entering the drains from slaughtering a whole carcass at SRM facilities were found to be from cattle infected with BSE at rendering and large incineration facilities with 7.4 BO ID50s (0.1, 29), intermediate plants and small incinerators with a mean of 4.5 BO ID50s (0.1, 18), and collection centers, 3.6 BO ID50s (0.1, 14). The lowest amounts entering drains are from lambs infected with classical and atypical scrapie at intermediate plants and atypical scrapie at collection centers with a mean of 3 × 10−7 OO ID50s (2 × 10−8, 1 × 10−6) per carcass. The results of this model provide key inputs for the model in the companion paper published here.

 


 

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.

 

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

 

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***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.

 

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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.

 

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***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.***

 

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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.

 

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

 

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 *** 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 ***

 


 

*** 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).***

 


 

***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.

 


 

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

 

Title: Evaluation of the zoonotic potential of transmissible mink encephalopathy

 

Authors

 

item Comoy, Emmanuel - item Mikol, Jacqueline - item Ruchoux, Marie-Madeleine - item Durand, Valerie - item Luccantoni-Freire, Sophie - item Dehen, Capucine - item Correia, Evelyne - item Casalone, Cristina - item Richt, Juergen item Greenlee, Justin item Torres, Juan Maria - item Brown, Paul - item Deslys, Jean-Philippe -

 

Submitted to: Pathogens Publication Type: Peer Reviewed Journal Publication Acceptance Date: July 30, 2013 Publication Date: July 30, 2013 Citation: Comoy, E.E., Mikol, J., Ruchoux, M., Durand, V., Luccantoni-Freire, S., Dehen, C., Correia, E., Casalone, C., Richt, J.A., Greenlee, J.J., Torres, J.M., Brown, P., Deslys, J. 2013. Evaluation of the zoonotic potential of transmissible mink encephalopathy. Pathogens. 2:(3)520-532.

 

Interpretive Summary: Cases of bovine spongiform encephalopathy (BSE) or mad cow disease can be subclassified into at least 3 distinct disease forms with the predominate form known as classical BSE and the others collectively referred to as atypical BSE. Atypical BSE can be further subdivided into H-type and L-type cases that are distinct from classical BSE and from each other. Both of the atypical BSE subtypes are believed to occur spontaneously, whereas classical BSE is spread through feeding contaminated meat and bone meal to cattle. Transmissible mink encephalopathy (TME) is another prion disease that transmits to cattle and show similarities to L-type BSE when subjected to laboratory testing. The purpose of this study was to use non-human primates (cynomologous macaque) and transgenic mice expressing the human prion protein to determine if TME could represent a potential risk to human health. TME from two sources (cattle and raccoons) was able to infect non-human primates and transgenic mice after exposure by the intracranial route. This result suggest that humans may be able to replicate TME prions after an exposure that allows infectious material access to brain tissue. At this time, it is unknown whether non-human primates or transgenic mice would be susceptible to TME prions after oral exposure. The results obtained in these animal models were similar to those obtained for L-type BSE. Although rare, the existence of TME and that it transmits to cattle, non-human primates, and transgenic mice suggest that feed bans preventing the feeding of mammalian tissues to cattle should stay in place and that regular prion surveillance during the slaughter should remain in place. Parties with interest in the cattle and beef industries and regulatory officials responsible for safe feeding practices of cattle will be interested in this work. Technical Abstract: Successful transmission of Transmissible Mink Encephalopathy (TME) to cattle supports the bovine hypothesis to the still controversial origin of TME outbreaks. Human and primate susceptibility to classical Bovine Spongiform Encephalopathy (c-BSE) and the transmissibility of L-type BSE to macaques assume a low cattle-to-primate species barrier: we therefore evaluated the zoonotic potential of cattle-adapted TME. In less than two years, this strain induced in cynomolgus macaques a neurological disease similar to L-BSE and distinct from c-BSE. TME derived from another donor species (raccoon) induced a similar disease with shorter incubation periods.

 

*** L-BSE and cattle-adapted TME were also transmissible to transgenic mice expressing human PrP. Interestingly, secondary transmissions to transgenic mice expressing bovine PrP showed the maintenance of prion strain features for the three tested bovine prion strains (cattle TME, c-BSE and L-BSE) regardless of intermediate host.

 

*** Thus, TME is the third animal prion strain transmissible to both macaques and humanized transgenic mice, suggesting zoonotic potentials that should be considered in the risk analysis of animal prion diseases for human health.

 

*** Moreover, the similarities between TME and L-BSE are highly suggestive of a link between those strains, and of the presence of L-BSE decades prior to its identification in USA and Europe.

 


 

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.

 


 


 

Monday, November 16, 2015

 

*** Docket No. APHIS-2007-0127 Scrapie in Sheep and Goats Terry Singeltary Sr. Submission ***

 


 


 

Wednesday, December 16, 2015

 

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

 


 

Thursday, January 14, 2016

 

EMERGING ANIMAL DISEASES Actions Needed to Better Position USDA to Address Future Risks Report to the Chairman, Committee on Energy and Commerce, House of Representatives December 2015 GAO-16-132

 

GAO

 


 

Terry S. Singeltary Sr.

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