The U.S. Department of Agriculture said on Monday it is collecting samples of ground beef at retail stores in states with outbreaks of bird flu in dairy cows for testing but remains confident the meat supply is safe.
The USDA will analyze the ground beef with tests that determine “whether any viral particles are present,” according to a statement. Some dairy cows are processed into ground beef when they grow old.
The USDA on Monday began requiring lactating dairy cows to test negative for bird flu before being shipped across state lines as the federal government seeks to contain the month-old outbreak.
The U.S. Food and Drug Administration said on Friday that preliminary results of gold-standard PCR tests of milk showed pasteurization killed the bird flu virus, as Colorado became the ninth U.S. state to report an infected dairy herd.
The USDA said it will analyze the retail beef samples with PCR tests, as well.
In another study, it will use a “virus surrogate” in ground beef and cook it at different temperatures to determine how the virus is affected, according to the statement. USDA said cooking meat to a safe internal temperature kills bacteria and viruses.
The department is also collecting beef muscle samples at slaughter facilities of dairy cattle that have been condemned to determine the presence of viral particles.
The USDA last week said it had found bird flu in a lung tissue sample from an asymptomatic dairy cow that was sent to slaughter from an infected herd. The animal did not enter the food supply, according to the USDA.
Colombia restricted the import of beef and beef products coming from U.S. states where dairy cows have tested positive for avian influenza as of April 15, according to the USDA.
There are no known cases of bird flu in beef cattle so far.