Consumers Union: cow needs retest for BSE

Cattle Market & Farm Reports, Editorials
Feb 28, 2005
by WLJ
Consumers Union last Thursday asked USDA to retest a cow that was determined in November 2004 to be negative for bovine spongiform encephalopathy (BSE) using a test called the “Western blot.”
The Western blot test is used by authorities in Japan and Europe when making a final determination as to whether a cow has the brain-wasting disease, Consumers Union said.
“Given the potential consequences to both public health and the cattle industry if this brain- wasting disease become established here, it is extremely important that every scientifically justifiable step be taken to prevent it," said Michael Hansen, a biologist with Consumers Union, and Jean Halloran, director of the group’s Consumer Policy Institute, in a letter Thursday to USDA Secretary Mike Johanns.
Representatives of the Consumers Union met with USDA officials earlier in February and urged the agency to revise its testing methods.
The Consumers Union is asking the USDA to not only retest the cow from November 2004, but also to send samples from the cow to the UK for independent testing.
USDA in November 2004 confirmed that the suspect cow was negative for BSE using the immunohistochemistry (IHC) test, which the agency describes as the "gold standard." However, the agency didn't perform the Western blot test, even though it had previously used both the IHC and Western blot in confirming the first case of BSE in the U.S. USDA also sent samples from that cow to the UK for further review.
Scientists in Japan and Belgium have reported that suspect cows may be negative on the IHC and still test positive on the Western blot. Such cows are universally regarded as infected, Consumers Union said.
In addition, the IHC is a more subjective test, relying on the judgments of a skilled scientist. The Western blot is more objective and its results can be read by any technician, according to Consumers Union. — WLJ