Aug 9, 2004 (CIDRAP News) – The US Department of Agriculture (USDA) said last week it would no longer announce an inconclusive result in testing cattle for bovine spongiform encephalopathy (BSE) after just one test, as it did twice in June.
John Clifford, chief veterinarian with the USDA Animal and Plant Health Inspection Service (APHIS), said the department would wait until at least two rapid BSE tests have produced the same outcome before announcing an inconclusive result.
The USDA came under criticism from the beef industry after it announced inconclusive BSE tests on two animals on successive days in late June. Confirmatory testing later ruled out the disease in both cases, but the public announcements shook the industry.
The department expanded its BSE surveillance program in June by authorizing a number of state veterinary laboratories to conduct rapid tests on cattle brains. The protocol involves running one test and, if it is inconclusive, running the same test two more times, according to the USDA.
Initially, the USDA policy was to declare a test inconclusive on the basis of the first test alone. Now, after evaluating the labs and the data from the first 2 months of testing, the department will wait until the second round of tests is done before declaring a result inconclusive, according to Clifford.
"If either of the tests in the second run is reactive, APHIS will announce this result as an inconclusive and will conduct confirmatory testing at National Veterinary Services Laboratories in Ames, Iowa," Clifford said.
The expanded surveillance program was triggered by the discovery of a single BSE case in Washington state last December. The USDA plans to test more than 200,000 cattle over 12 to 18 months in an effort to ascertain if more BSE cases exist in American herds.
USDA figures show that 32,698 cattle had been tested in the program as of yesterday, with no BSE cases found.