On April 24, the Food and Drug Administration (FDA) announced that traces of H5N1 bird flu had been detected in about 20 percent of milk samples from U.S. grocery stores, and reemphasized that the commercial milk supply of pasteurized milk is still safe for consumption.

The pasteurization process inactivates harmful bacteria and viruses, which means that the found traces of H5N1 bird flu are not live or infectious virus. Many studies have shown that pasteurization is effective at inactivating similar influenza viruses.

According to experts, finding traces of the virus in this percentage indicates that the H5N1 bird flu outbreak in cows is larger than originally thought. USDA has announced mandatory testing for bird flu for any dairy cows moving across state lines. Only milk from healthy animals is authorized to be sold, and pasteurization is required for any milk entering interstate commerce.

FDA will continue to monitor the milk supply and has cautioned against the consumption of raw or unpasteurized milk or milk products.

Additionally, to keep the beef supply safe, the U.S. Department of Agriculture (USDA) has conducted testing of ground beef samples from retail outlets in states where cows have tested positive for the virus. To date, no H5N1 virus has been found in any of the tested samples. Testing will continue and only meat that has passed USDA inspection can be sold in U.S. stores and restaurants.

Note: When communicating with the public about the H5N1 bird flu outbreak and the safety of the milk and beef supplies, public health officials should emphasize that their information is based on what is known to date, and that health guidance could change as more information becomes available. Continued monitoring for any further circulation of the virus by federal, state, and local officials is critical to protecting the public’s health.

Updated May 14, 2024