USDA Confirms TSE in Sheep; Testing Continues

April 12, 2002

USDA says tests conducted on a flock of sheep confiscated last year from a farm in Vermont confirm that two of the 125 sheep tested positive for an atypical undifferentiated transmissible spongiform encephalopathy (TSE) of foreign origin. The flock of 125 sheep was confiscated in March 2001 after four animals from an associated flock tested positive for TSE in July 2000. USDA will continue to conduct additional tests to determine the type of TSE in these sheep.

None of the confiscated animals entered the animal or human food supply. The sheep, imported from Belgium and the Netherlands in 1996, were placed under certain federal restrictions when they entered the country as part of USDA's scrapie control efforts. In 1998, USDA learned that it was likely that sheep from Europe were exposed to feed contaminated with bovine spongiform encephalopathy. At that time, the state of Vermont, at the request of USDA, imposed a quarantine on these flocks, which prohibited slaughter or sale for breeding purposes.

On July 10, 2000, several sheep from the flock tested positive for a TSE, a class of degenerative neurological diseases that is characterized by a very long incubation period and a 100 percent mortality rate in infected sheep. Two of the better known varieties of TSE are scrapie in sheep and BSE in cattle. There is no evidence that scrapie poses a risk to human health.

Four days later, USDA issued a declaration of extraordinary emergency to acquire the sheep. This action was contested by the flock owners. A federal district court judge ruled in favor of USDA based on the merits of the case. The flock owners appealed to the Second Circuit Court requesting a stay, which was denied.

The sheep were confiscated by USDA in March 2001 and transported to USDA's National Veterinary Services Laboratories in Ames, IA, where they were humanely euthanized. Tissue samples were collected from the sheep for diagnostic testing and USDA will continue with additional tests which could take up to two to three years to complete. In all, USDA has acquired 380 sheep from a total of three flocks. All of the animals were humanely euthanized, sampled and disposed and did not enter the animal or human food supply.

For more information about USDA's ongoing surveillance, monitoring and prevention efforts as it relates to this situation, please visit www.aphis.usda.gov/oa/tse/index.html.