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Atypical scrapie in a swiss goat and implications for.......

flounder

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Full Scientific Reports

Atypical scrapie in a swiss goat and implications for transmissible spongiform encephalopathy surveillance

Torsten Seuberlich1, Catherine Botteron, Sylvie L. Benestad, Hervé Brünisholz, Reto Wyss, Ulrich Kihm, Heinzpeter Schwermer, Martina Friess, Alexandra Nicolier, Dagmar Heim and Andreas Zurbriggen
Correspondence: 1 Corresponding Author: Torsten Seuberlich, NeuroCenter, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, Bremgartenstrasse 109a, CH-3001 Berne, Switzerland, e-mail: [email protected]


Different types of transmissible spongiform encephalopathies (TSEs) affect sheep and goats. In addition to the classical form of scrapie, both species are susceptible to experimental infections with the bovine spongiform encephalopathy (BSE) agent, and in recent years atypical scrapie cases have been reported in sheep from different European countries. Atypical scrapie in sheep is characterized by distinct histopathologic lesions and molecular characteristics of the abnormal scrapie prion protein (PrPsc). Characteristics of atypical scrapie have not yet been described in detail in goats. A goat presenting features of atypical scrapie was identified in Switzerland. Although there was no difference between the molecular characteristics of PrPsc in this animal and those of atypical scrapie in sheep, differences in the distribution of histopathologic lesions and PrPsc deposition were observed. In particular the cerebellar cortex, a major site of PrPsc deposition in atypical scrapie in sheep, was found to be virtually unaffected in this goat. In contrast, severe lesions and PrPsc deposition were detected in more rostral brain structures, such as thalamus and midbrain. Two TSE screening tests and PrPsc immunohistochemistry were either negative or barely positive when applied to cerebellum and obex tissues, the target samples for TSE surveillance in sheep and goats. These findings suggest that such cases may have been missed in the past and could be overlooked in the future if sampling and testing procedures are not adapted. The epidemiological and veterinary public health implications of these atypical cases, however, are not yet known.

http://jvdi.org/cgi/content/abstract/19/1/2



Subject: NOR98-LIKE STRAIN OF SCRAPIE FOUND IN WYOMING
Date: April 11, 2007 at 12:47 pm PST

PRESS RELEASE

March 16, 2007

Wyoming Livestock Board

2020 Carey Avenue 4th Floor

Cheyenne, Wyoming 82002

For more information contact: Dr. Walter Cook at (307) 631-2974 [weekend] or (307) 777-6443 [weekday]

*****FOR IMMEDIATE RELEASE*****

NOR98-LIKE STRAIN OF SCRAPIE FOUND IN WYOMING

CHEYENNE, Wyo. - On Friday, March 16, 2007, the Wyoming Livestock Board (WLSB) was notified by officials of the USDA Animal Plant Health Inspection Service (APHIS) that an adult female sheep had tested positive for a form of scrapie consistent with the Nor98 strain. The ewe was slaughtered in Michigan, where it was tested as part of USDA’s regulatory scrapie slaughter surveillance program and traced back to a flock in Wyoming. The results of this case are distinctly different from those seen for bovine spongiform encephalopathy (BSE) or classical scrapie.

Scrapie is a transmissible spongiform encephalopathy and falls into the same category of diseases as chronic wasting disease, found in deer and elk, and bovine spongiform encephalopathy, found in cattle. The disease is limited to sheep and goats and takes years to affect an animal after it has been infected. Scrapie causes sheep to itch and scratch (scrape) wool off, change their behavior and lose body condition; it ultimately ends in death.

Nor98-like scrapie differs from classical scrapie in the distribution of brain lesions and in the course of disease progression and epidemiology. Some sheep that are genetically resistant to the classic form of the disease may be susceptible to the Nor98-like strain. Oddly, Nor98-like scrapie is usually diagnosed during surveillance in animals without clinical signs. There are no known human health risks associated with either form of scrapie.

This is the first time a Nor98-like strain of scrapie has been documented in the United States. It gets the "Nor98-like" name because it is similar to a case first diagnosed in Norway in 1998. This strain of scrapie is a rare disease even in Europe. Since 1998, fewer than 300 cases have been diagnosed in all of Europe. It is usually seen in single animals and does not tend to become widespread in a flock. In contrast, in flocks infected by classical scrapie typically more than 10 percent of the genetically susceptible animals test positive.

"This provides evidence that the surveillance program is working," said Bryce Reece, executive director of the Wyoming Wool Growers Association. "It also indicates that the program is on the cutting-edge of science to detect such a rare disease during standard surveillance."

The Wyoming Livestock Board does not expect the Nor98-like strain of scrapie to become a major disease problem for the sheep industry in Wyoming. Risk is limited because diagnosis of Nor98-like scrapie is usually an incidental event, with even highly-exposed flock mates of the positive animal normally unaffected.

The infected ewe lambed in it in what is considered a low-risk, range-lambing environment. Nonetheless, the WLSB, APHIS and the Wyoming Wool Growers Association plan to assertively pursue this case to make sure that this strain of scrapie is extinguished and does not establish itself in the U.S.

The agencies continue to encourage producers to monitor their sheep for signs of scrapie and other diseases, and to notify their veterinarian if they discover anything unusual.

The positive ewe was purchased as an adult within the last several years and moved to a Wyoming flock near the Black Hills. The producer was notified and his flock quarantined as a precautionary measure. An epidemiologic investigation is ongoing and the producer has been cooperative. The case fits the pattern found in Europe - a single, older sheep that was not exhibiting clinical signs of scrapie.

The regulatory scrapie slaughter surveillance program is a targeted slaughter surveillance program for sheep and goats designed to identify infected animals and flocks. USDA is conducting this surveillance as part of a program to eradicate scrapie from the United States by the end of 2010. Reece said that the sheep industry supports this program and is committed to eliminating scrapie from the United States.

###


http://wlsb.state.wy.us/NewReleases/07Mar16FINALNOR98LIKESCRAPIEPRESSRLS.pdf





FOIA REQUEST FOR ATYPICAL TSE INFORMATION ON VERMONT SHEEP
Re: FOIA REQUEST FOR ATYPICAL TSE INFORMATION ON VERMONT SHEEP (4843 lines)
From: Terry S. Singeltary Sr. <[log in to unmask]>
Date: Mon, 2 Apr 2007 14:43:32 -0500

http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0704&L=sanet-mg&T=0&P=816



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