FDA Detects Bird Flu Virus in Pasteurized Milk Samples Across U.S.

The U.S. Food and Drug Administration (FDA) announced on April 24, 2024, that it has detected fragments of the bird flu virus in samples of pasteurized milk from grocery stores across the country. While the agency maintains that the milk supply remains safe for consumption, the findings suggest that the current outbreak of highly pathogenic avian influenza (HPAI) among dairy herds is more widespread than previously thought.

The FDA's testing, using polymerase chain reaction (PCR), found genetic evidence of the H5N1 bird flu virus in the milk samples. However, the agency stated that the tests cannot distinguish between live virus or fragments of viruses that could have been killed by the pasteurization process. The FDA is conducting further testing to determine if it can grow live virus from the milk samples and assess the safety of the milk supply.

Over the past month, the H5N1 virus has been detected in more than 30 dairy herds across eight states, including Texas, Kansas, Michigan, New Mexico, and Idaho. The outbreak has caused symptoms such as decreased lactation, low appetite, and discolored milk in affected cattle. The virus has also infected one farmworker in Texas, who experienced mild symptoms of pink eye, marking the second case of bird flu in a human in the U.S.

Why this matters: The detection of bird flu virus fragments in the nation's pasteurized milk supply raises concerns about the potential spread of the virus to humans and the safety of dairy products. While the risk to the general public remains low, health officials are closely monitoring the situation to prevent further transmission and ensure the outbreak is contained.

The FDA, along with the U.S. Department of Agriculture (USDA) and the Centers for Disease Control and Prevention (CDC), is investigating the outbreak and working to understand the spread of H5N1 among dairy cows. Preliminary testing at the University of Wisconsin-Madison has indicated that pasteurization is effective in killing the virus, but the USDA is also conducting its own trials on the impact of pasteurization on H5N1.

Key Takeaways

• FDA detected bird flu virus fragments in pasteurized milk nationwide.
• Outbreak has infected over 30 dairy herds across 8 states.
• Pasteurization may kill the virus, but further testing is ongoing.
• FDA maintains commercial milk supply is safe, but monitoring situation.
• Experts criticize slow federal response and lack of cattle testing.