USDA Says Dairy Cows Can't Travel Without Flu Check

UPDATE Apr 24, 2024 5:25 PM CDT

Dairy cows can no longer cross state lines without being tested for bird flu, federal authorities said Wednesday, the day after the FDA announced that inactive viral fragments had been found in pasteurized milk. The US Department of Agriculture said dairy cows need to test negative for influenza A viruses before they can be transported across state lines, the New York Times reports. The tests will protect livestock and help officials "better understand this disease," said USDA official Mike Watson. The agency says the outbreak has spread to 33 herds in eight states. Dozens of people are being monitored for infection, but only one person, a dairy worker in Texas, has had a confirmed case of bird flu.

Apr 24, 2024 3:00 AM CDT

Inactive viral fragments from the bird flu virus have been found in samples of pasteurized milk from US grocery store shelves. In announcing the news, the Food and Drug Administration said consumers are not at risk from the inactive viral remnants, the New York Times reports. A public health official tells the Washington Post the more concerning implication is that this news suggests the avian influenza virus is more widespread among herds of dairy cows than was previously thought. WHO warned last week that the virus had been found in raw milk, the New York Post reports.

Unlike raw milk, however, commercial milk is pasteurized; pasteurization inactivates pathogens so they're no longer harmful, but does not typically does not remove genetic material, so the presence of fragments in the milk supply is not unexpected. "To date, we have seen nothing that would change our assessment that the commercial milk supply is safe," the FDA says. It's not yet clear how many samples tested positive or where those samples originated. This strain of bird flu has infected more than two dozen livestock herds in at least eight states over the past month, causing concern among observers of the virus, which has circulated among birds for more than two decades. (More bird flu stories.)