Fragments of Bird Flu Virus Discovered in Milk

Federal regulators said on Tuesday that samples of pasteurized milk from around the country had tested positive for inactive remnants of the bird flu virus that has been infecting dairy cows.

The viral fragments do not pose a threat to consumers, officials said. “To date, we have seen nothing that would change our assessment that the commercial milk supply is safe,” the Food and Drug Administration said in a statement.

Over the last month, a bird flu virus known as H5N1 has been detected in more than 30 dairy herds in eight states. The virus is also known to have infected one farmworker, whose only symptom was pink eye.

Scientists have been critical of the federal response, saying that the Agriculture Department has been too slow to share important data and has not adequately pursued the testing of cattle for the infection.

Finding viral fragments in milk from the commercial supply chain is not ideal, but the genetic material poses little risk to consumers who drink milk, said David O’Connor, a virologist at the University of Wisconsin-Madison.