Raw Milk in California Contains Avian Flu, According to Testing

The California Department of Public Health has announced that “sampling of retail raw milk for avian flu turned up a positive sample, based on testing at the Santa Clara Public Health Laboratory.” CIDRAP has the news.

Milk from infected cows “contains extremely high levels of the H5N1 virus. Pasteurization inactivates the virus, and though H5N1 viral fragments have been found in some retail milk samples, none contained live virus.”

The CDPH is also urging consumers to avoid “drinking a batch of whole raw milk produced by Raw Farm, LLC, based in Fresno County. The farm is located in California's Central Valley, which has experienced a surge of avian flu outbreaks in dairy cattle—402 since late August.” No related human illnesses tied to this outbreak have been reported thus far.

CDC says that about “4.4% of US adults consume raw milk at least once a year, and though concerns persist about whether raw milk or products made with raw milk could transmit the avian flu virus to people, the level of risk isn't currently known.” Unpublished mouse studies suggest that there is a “risk of infection from oropharyngeal (mid-throat) administration of contaminated milk. Drinking unpasteurized milk contaminated with H5N1 could bind to a limited number of receptors in the upper airways or, if the milk were aspirated, could infect lower-airway receptors that allow better H5N1 binding.”