Failure to detect scrapie virus in sheep at slaughter in a highly endemic region of France.

A study was carried out in a sheep slaughterhouse located in a region of France where scrapie has been endemic for several decades. Neuropathological examination of 63 randomly selected lambs and adult sheep revealed no scrapie-related abnormalities, and inoculation of mice with brain, tonsil, lateropharyngeal ganglia, and intestine from the same animals did not transmit scrapie. The failure to detect any evidence of scrapie infection in commercially-bred sheep, the absence of an increased mortality rate for human CJD in the surrounding consumer region, and the absence of a single case of CJD among slaughterhouse personnel, do not support the hypothesis that exposure to potentially scrapie-contaminated products is responsible for CJD in humans.