Bovine tissue from sick cow tests positive for bird flu virus

Beef tissue from a sick dairy cow tested positive for the avian flu virus, federal officials announced Friday.

The cow was ordered to be slaughtered because it was sick and its meat did not enter the food supply, according to the U.S. Department of Agriculture. The ministry continued to emphasize that the commercial food supply remained secure.

But the positive test, part of an ongoing federal study into beef safety, raises concerns about whether the virus could find its way into the commercial beef supply, posing a risk for human health.

So far, the USDA Food Safety and Inspection Service has tested tissue samples from 96 dairy cows that had been condemned due to signs of illness. Only one cow tested positive, the department said. Meat from condemned cows is not permitted in the commercial food supply.

The agency is testing additional muscle samples.

It did not find virus in ground beef samples collected from retail outlets in states where cows tested positive.

Earlier this month, the agency released the results of an experimental study in which high concentrations of virus were introduced into very large beef patties — 300 grams, compared to 113 grams for a typical hamburger. The researchers found no viruses present in the meat when they cooked the hamburger to 160 degrees Fahrenheit, the internal temperature of a well-cooked hamburger, or to 145 degrees Fahrenheit, the temperature of a hamburger cooked over medium heat. .

However, the virus was present in rare hamburgers, cooked at 120 degrees, although at significantly reduced levels; the agency said cooking at that temperature “significantly inactivated the virus.”

“All the indications are: You cook your food, even if there is a virus in it, it will kill it,” said Stacey Schultz-Cherry, a virologist and flu expert at St. Mary’s Children’s Research Hospital. . Jude.

Food safety experts have expressed particular concern about the risk of transmission through raw milk.

Food safety experts recommend always cooking meat thoroughly to prevent infection with other, more common pathogens such as salmonella, listeria and E.coli. “These food safety recommendations existed long before H5N1 became a problem, and they should always be our baseline standard,” said Dr. Keith Poulsen, director of the Wisconsin Veterinary Diagnostic Laboratory at the University of Wisconsin. Wisconsin-Madison.