Bird Flu Traces Found in Grocery Store Milk, FDA Assures Safety

The U.S. Food and Drug Administration (FDA) revealed on Tuesday that traces of the H5N1 avian influenza virus were found in milk purchased at grocery stores. Despite the discovery, the FDA insists that pasteurized milk is safe for consumption.

The FDA believes the viral particles detected in milk result from the remnants of viruses destroyed during the pasteurization process. While further testing is underway to ensure complete safety, the agency doesn’t believe the particles pose an infection risk to humans.

“To date, we have seen nothing that would change our assessment that the commercial milk supply is safe. Results from multiple studies will be made available in the next few days to weeks,” the agency said.

Dr. Eric Topol of the Scripps Research Translational Institute believes the finding highlights a greater spread of the outbreak than previously understood. He cautioned in an email Tuesday, “The dissemination to cows is far greater than we have been led to believe.”

Topol expressed doubts about the FDA’s blanket safety assurance, suggesting it may erode public trust after the USDA’s prior handling of the outbreak.

The U.S. Department of Agriculture (USDA) confirmed the first-ever detection of highly pathogenic avian influenza in cattle in late March. Since then, the virus has been identified in over 30 farms across eight states. Researchers are still working to pinpoint the initial infection source and understand how the virus spreads among cattle.

Infected cows have shown symptoms such as reduced appetite and discolored milk. Veterinarians discovered large amounts of the virus in their milk, suggesting direct infection of the mammary glands.

The FDA emphasizes that milk from sick cows is not entering the market, while milk sold across states undergoes pasteurization to kill microbes. However, as pasteurization doesn’t guarantee complete sterility, the FDA is actively testing milk samples nationwide, collaborating with the CDC for heightened vigilance.

Experts like Dr. Richard Webby of the World Health Organization highlight the unexpected nature of the outbreak, noting that H5N1 detection in cows was unforeseen. This unique situation appears to have led to gaps in reporting protocols.

Unlike poultry, where H5N1 reporting is mandatory and incentivized, cattle reporting remains voluntary. Dr. Michael Osterholm of the Center for Infectious Disease Research and Policy worries the outbreak could spread to pigs, which – like humans – possess the receptors the virus needs to adapt and potentially become more infectious to people.

The USDA encourages voluntary reporting of sick cattle and is monitoring health data for anomalies. However, there’s no widespread testing of cows or their handlers, nor is wastewater testing actively underway.