USA – The USDA is set to implement a tiered strategy to begin testing bulk raw milk for bird flu contamination in an effort to control the rapid spread of the virus.
In partnership with state veterinarians, USDA will collect milk samples to better assess where H5N1 is present, with the goal to better inform biosecurity and containment measures.
The information will help inform state-led efforts to reduce risk to farm workers who may be in contact with animals infected with H5N1.
“Data collected over the past seven months has shown that H5N1 can be transmitted on equipment, people, or other items that move from farm to farm, including between dairies and poultry facilities,” according to a USDA announcement.
A multistate outbreak of HPAI A(H5N1) bird flu in dairy cows was first reported on March 25, 2024. This is the first time that these bird flu viruses had been found in cows. In the United States, since 2022, USDA APHIS has reported HPAI A(H5N1) virus detections in more than 200 mammals.
On April 1, CDC confirmed one human HPAI A(H5N1) infection in a person with exposure to dairy cows in Texas that were presumed to be infected with the virus. This is thought to be the first instance of likely mammal to human spread of HPAI A(H5N1) virus.
In May 2024, CDC began reporting additional, sporadic human cases in people who had exposure to infected dairy cows.
According to the American Journal of Managed Care, industry has pushed for enhanced surveillance, which is part of what prompted the USDA to implement bulk raw milk testing. Bulk milk testing in Colorado has successfully reduced new bird flu cases in dairy cows.
As for the risk to consumers, the CDC and USDA report that the virus is inactivated by pasteurization of milk.
However raw, unpasteurized milk is still a concern and health officials warn consumers to not consume it because of potential contamination with H5N1 as well as E. Coli, Salmonella and other foodborne pathogens.
Meanwhile, a pig in Oregon has tested positive for the H5N1 bird flu virus. It’s the first time the virus has been detected in swine in the United States.
The five pigs were tested for H5N1 out of an abundance of caution, officials said, and “because of the presence of H5N1 in other animals on the premises.”
The case is concerning as pigs can become infected with both bird and human viruses at the same time, which can give rise to mutated strains that can more easily infect humans.
