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United States Department of Agriculture

Agricultural Research Service

Title: Antemortem, Postmortem, and Genetic Testing in Scrapie Control

Authors
item O'Rourke, Katherine
item Baszler, T - WASHINGTON STATE UNIV
item Parish, S - WASHINGTON STATE UNIV
item Knowles, Donald

Submitted to: Proceedings of the Office International Des Epizooties World Association of
Publication Type: Proceedings
Publication Acceptance Date: June 1, 1999
Publication Date: N/A

Technical Abstract: Control of scrapie in U.S. flocks since introduction of the disease in the 1940's has been based on epidemiology. Clinically suspect sheep are euthanized and scrapie is confirmed by postmortem examination of the brain for the characteristic lesions and deposition of the marker prion protein. In 1998, we reported a noninvasive technique for collecting lymphoid tissue from the nictitating membrane of clinically normal sheep and assaying for the prion protein by monoclonal antibody based immunohistochemistry. This assay allows us to (1) determine the correlation between prion protein in lymphoid tissue of sheep during early infection and eventual progression to disease, (2) determine whether removal of infected sheep from a flock is an effective tool for control, (3) determine the correlation between genotype and prion accumulation in lymph nodes, both in the absence and presence of clinical disease and neural immunostaining, (4) extend our understanding of scrapie transmission in a flock, and (5) identify extraneural tissues suitable for postmortem identification of scrapie infected sheep that were normal at slaughter.

Last Modified: 4/19/2014