BSE test a false alarm

WASHINGTON – The inconclusive screening test sample for mad cow disease that jolted the U.S. cattle industry Nov. 18 turned out to be negative.
The USDA’s National Veterinary Services Lab in Ames, Iowa, received the negative result using the internationally recognized “gold standard” test, or immunohistochemistry (IHC) test, for bovine spongiform encephalopathy.
Results were announced Nov. 23.
Ran twice. Because the initial sample was showing positive in both a first and repeat rapid test at the initial lab, the Ames lab ran the immunohistochemistry test a second time.
“Negative results from both IHC tests make us confident that the animal in question is indeed negative for BSE,” said John Clifford, deputy administrator with the USDA’s Animal & Plant Health Inspection Service.
Because the rapid tests are extremely sensitive, Clifford said, false positives are not unexpected.