USDA to Expand Testing of Milk Supply to Track Spread of Bird Flu in Cattle
The U.S. Department of Agriculture (USDA) will begin testing raw milk from dairy silos across the country as part of a new initiative to track the spread of the H5N1 bird flu, which has been affecting dairy cattle since March.
The USDA announced the expansion of testing in a federal order issued on Friday. Infectious disease experts have long advocated for increased testing to better understand where the virus is spreading, emphasizing that without this information, the virus cannot be contained. While dairy farmers initially resisted more widespread testing due to concerns about potential quarantines and income loss, the new initiative aims to provide greater confidence in animal safety.
“Among many outcomes, this will give farmers and farmworkers better confidence in the safety of their animals and ability to protect themselves, and it will put us on a path to quickly controlling and stopping the virus’ spread nationwide,” said Agriculture Secretary Tom Vilsack in a press release.
Under the new order, dairy farms, bulk milk shippers, milk transfer stations, and dairy processing facilities are required to share raw milk samples upon request. Additionally, herd owners with cattle that test positive for the bird flu will be asked to provide information to aid in contact tracing and disease surveillance. Labs and veterinarians who detect the virus must also report positive results to the USDA.
The USDA will begin testing milk stored in silos at dairy processing facilities across the country, with plans to expand to bulk tank testing at farms based on these initial results. If positive cases are identified, officials will work swiftly to isolate the affected herds and implement biosecurity measures. Once the herds in each state are cleared, continued testing will ensure that the virus does not re-emerge.
The first round of testing is set to begin the week of December 16, although some states have already started complying with the new requirements. The initial testing will cover six states: California, Colorado, Michigan, Mississippi, Oregon, and Pennsylvania. While California, Colorado, and Michigan have reported infected herds, Mississippi, Oregon, and Pennsylvania have not yet seen confirmed cases, making testing in these areas essential for understanding the virus’s potential spread.
The USDA first announced its National Milk Testing Strategy in October, and Friday’s order provides the specific details of how it will be implemented.
Milk testing will occur before pasteurization, which kills harmful bacteria and viruses. “Even if the virus is detected in raw milk, the current pasteurization process will inactivate the virus,” the U.S. Food and Drug Administration (FDA) stated. Nearly all milk sold in the U.S. is pasteurized.
Despite this, health officials have long advised against consuming raw milk or feeding it to animals due to the risk of disease-causing pathogens, including listeria, E. coli, and the bird flu virus. Recently, Raw Farm milk in California was recalled after bird flu was detected in samples from store shelves and dairy processing sites, though no illnesses have been linked to the products.
Through these expanded testing efforts, the USDA aims to better understand the scope of the H5N1 outbreak and reduce the impact of the virus on both the dairy industry and public health.
