USA - Positive Brucellosis Test on Wyo. Cow May Be Wrong
Published:November 4, 2004
Source :South Dakota Ag Connection
Test contamination is now the leading theory why positive results for brucellosis came back for two Campbell County cows last summer.
The testing was done at a state laboratory in Brookings, S.D. But follow-up tests, including tests of other cattle in the herd and neighboring herds, have turned up no sign of brucellosis in northeast Wyoming.
South Dakota state veterinarian Sam Holland said Monday that analysis of DNA from the brucellosis bacteria from the Campbell County cows matched DNA from brucellosis bacteria that were sampled from bison in 1994.
"We may need to review lab protocol nationwide," he said. "Perhaps we need to do a better job of keeping isolates separate from one another."
A U.S. Department of Agriculture review concluded that proper procedures were followed at the Brookings laboratory. But Holland said that does not mean contamination was impossible. Another possibility is that elk may have transmitted brucellosis to the cows. A special hunt to test elk for the disease is being held in the area until Nov. 7.
"We're still waiting to pull all the epidemiology together after the elk tests come back, and the USDA isn't going to make any decision until all the information is in," Bret Combs, the federal veterinarian for Wyoming, said.
Hunters have agreed to sample blood from any elk they kill so it can be tested for brucellosis. Full results are not expected until early next month, but preliminary tests from elk killed in the hunt have come back negative.
Wyoming lost its federal brucellosis-free status after the disease began turning up in cattle late last year. Other states since have imposed restrictions on importing Wyoming cattle and brucellosis testing for Wyoming cattle has been ramped up.
