WASHINGTON, June 24 (UPI) -- The U.S. Department of Agriculture said Friday a cow being retested for mad cow disease was positive, marking the second case of the deadly disease detected in U.S. herds in less than two years.
The USDA also announced that in the future it would run two types of confirmatory tests if another cow initially tests positive on rapid tests.
"I want to make sure we continue to give consumers every reason to be confident in the health of our cattle herd," Agriculture Secretary Mike Johanns said. "By adding the second confirmatory test, we boost that confidence and bring our testing in line with the evolving worldwide trend" to use two confirmatory tests.
The USDA had cleared the animal free of the disease last November, although it had twice tested positive on rapid tests. Agency personnel ran a more sophisticated test called immunohistochemistry, which did not find any indications of the disease. The agency, however, did not conduct a second kind of test called a Western blot, which many countries do when faced with conflicting results.
The USDA's Office of Inspector General, for reasons that have not yet been made public, requested the agency run the Western blot on the cow earlier this month, and it came back positive. To confirm the infection, the USDA last week sent a sample of the cow's brain to an internationally recognized laboratory in Weybridge, England, which concluded it was positive after running rapid tests, IHC and Western blot.
The USDA has not yet completed its investigation into where the cow originated, but the agency said the infected animal did not go into the human food supply. This is a concern because humans can contract a fatal, brain-wasting disease from consuming beef products contaminated with the mad cow pathogen.
"Americans have every reason to continue to be confident in the safety of our beef," Johanns said.
However, the watchdog group Consumers Union is concerned that mad cow could be amplified in U.S. herds because there are loopholes in a 1997 ban that prohibits cow tissues from being incorporated into cattle feed.
"Even the remains of an animal known to carry a mad cow-type disease could legally go into feed for pigs, chickens and pets under current Food and Drug Administration rules," Consumers Union said in a statement. They urged the government to "tighten the rules on animal feed ingredients that can transmit mad cow disease, including closing the loopholes in animal feed rules that allow the feeding of cow's blood and chicken coop floor waste to cattle."
The USDA said the infected animal was born before the 1997 feed ban.
Consumers Union said consumers who want to minimize their risk should avoid eating cow brains and other processed beef products, like sausages and hot dogs, that could contain central nervous system tissue, which can carry the mad cow pathogen. Consumers could also opt for beef products from organic or grass-fed cows because they are not fed the remains of other animals, the group said.
