The U.S. government is testing ground beef at retail stores in states with outbreaks of bird flu in dairy cows to ensure safety. The outbreaks of the H5N1 virus have been confirmed in 34 dairy cattle herds in nine states since late March. Federal officials are seeking to verify the safety of milk and meat, with preliminary results showing that pasteurization kills the bird flu virus in milk. The U.S. Centers for Disease Control and Prevention and the World Health Organization have stated that the overall public health risk is low, but higher for those with exposure to infected animals.
Scientists believe that the outbreaks of bird flu are more widespread in cows than officially reported, based on findings of H5N1 particles in about 20% of milk samples. The U.S. Department of Agriculture is conducting additional testing on retail ground beef samples to determine the presence of viral particles. Dairy cows are sometimes processed into ground beef when they grow old. USDA has also started requiring lactating dairy cows to test negative for bird flu before being moved across state lines. Testing is not required for cows shipped directly to slaughter facilities from barns where they are sold.
USDA is collecting beef muscle samples at slaughter facilities of dairy cattle that have been condemned to check for viral particles. Any positive PCR tests for retail or slaughter samples will be evaluated for the presence of live virus. In a safety study, USDA will cook ground beef containing a “virus surrogate” at different temperatures to assess how it inactivates the virus. Colombia has restricted the import of beef and beef products from U.S. states where dairy cows have tested positive for avian influenza as of April 15. So far, there are no known cases of bird flu in beef cattle.
Last week, USDA 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 department. The human case in the current outbreak was in a Texas farm worker who suffered conjunctivitis following exposure to dairy cows. The Meat Institute, an industry group representing meat processors, has stated that USDA’s additional testing is appropriate to ensure public health is protected and to stop the spread of animal disease. USDA inspects each animal before slaughter, and all cattle carcasses must pass inspection after slaughter to enter the human food supply.
