Avian influenza remains active in dairy cattle in the US

The surge in avian influenza on US dairy farms this winter continues to cause concern in the sector. The disease has been found in animals on approximately 90 dairy farms in a total of 10 states in North America. This forces extreme precautions when moving cows between states.

This June, the US government is implementing a pilot plan for voluntary milk tank testing so that farms wishing to transport their animals to other states can prove they are free of the disease through weekly milk tank tests.

The problem appears to be serious because lack of control in the early months of the disease, likely between December 2023 and March 2024, led to the widespread spread of avian influenza. Health authorities have confirmed that up to 20% of milk on the market contains avian influenza virus particles, although no commercial milk contained live virus or had any ability to infect humans.

The US Food and Drug Administration emphasizes that heat treatment of milk (pasteurization or UHT) completely inactivates the virus, so consumption of commercial milk remains 100% safe.

Similarly, laboratory tests were conducted to inoculate avian influenza virus into beef that was subsequently cooked and proved that cooking inactivated the virus. So far, only one carcass contaminated with avian influenza has been found at the slaughterhouse and removed from the food chain.

Regarding the human exposure associated with the avian influenza outbreak, the only factor is that three meat farm workers were infected by animals.

Europe, free
No cases of bird flu have yet been identified on beef farms in Europe, although health authorities are closely monitoring the situation in the US, which is causing concern.

Bird flu in cattle: situation and prospects