Beef tissue from sick dairy cows The test came back positive. Federal officials said Friday that it was against the avian influenza virus.
The decision was made to cull the cow because of illness and its meat was not added to the food supply, according to the USDA, which continued to stress that the commercial food supply remains safe.
But the positive test, which comes as part of an ongoing federal investigation into beef safety, has raised concerns that the virus could get into the commercial beef supply and pose a risk to human health.
The USDA Food Safety and Inspection Service has tested tissue samples from 96 dairy cows that were culled for showing signs of disease. Only one tested positive, the service said. Meat from culled cows is not allowed into the commercial food supply.
The agency is testing additional muscle samples.
No virus was found in ground beef samples taken from stores in states where cattle had tested positive.
Earlier this month, the department Announced results In an experimental study, researchers put high concentrations of the virus into very large beef patties (300 grams versus 113 grams for a regular hamburger). They found that when the burgers were cooked to the internal temperature of a well-done burger, 160 degrees Fahrenheit, or the temperature of a medium-cooked burger, 145 degrees Fahrenheit, the virus was not present in the meat.
But the virus was present in the rare burger cooked at 120 degrees, but at significantly reduced levels. Cooking at that temperature “largely inactivated the virus,” the agency said.
“All indications are that cooking food kills the virus, even if it’s on there,” said Stacey Schultz Cherry, a virologist and influenza expert at St. Jude Children’s Research Hospital.
Food safety experts have expressed particular concern about the risk of infection 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 were in place long before H5N1 became an issue and should always be the baseline standard,” said Dr. Keith Paulsen, director of the Wisconsin Veterinary Diagnostic Laboratory at the University of Wisconsin-Madison.
