The U.S. Department of Agriculture announced Friday that it would soon begin testing the country’s milk supply for H5N1, the virus that causes bird flu.
Milk has been a central concern as cases of bird flu have ticked up over the past year. Researchers believe the virus has spread between cows and to farmworkers through contaminated milk. More than 700 dairy herds have been affected by the virus, and at least 58 people, mostly farmworkers, have been sickened.
Here’s what we know about the virus and its potential impact on milk.
Why do officials want to test unpasteurized milk?
Health officials will begin testing milk from large storage tanks at dairy processing facilities, which typically pool milk from many dairy farms, before it is pasteurized. Farmers and dairy processors will also have to provide milk samples if the government requests them, and provide details to help identify more cases if a sample is positive. This testing was previously voluntary.