Bird flu virus detected in raw milk from dairy farm based in Fresno, Calif.

The bird flu virus was detected in a retail sample of raw milk from a California-based dairy farm as cases continue to rise across the state, health officials announced. 

The contaminated sample came from Fresno-based Raw Farm, the largest producer and retailer of raw dairy in California. The tainted sample was detected by officials from the Santa Clara County public health office, which has been testing raw milk already placed in retail stores across the state “as a second line of consumer protection.”

Raw Farms has since issued a voluntary recall of all quart and half-gallon milk products produced on Nov. 9. The products are set to expire on Nov. 27 and have the lot ID #20241109.

No cases associated with the Raw Farms products have been reported yet. 

“This isn’t surprising, given how quickly H5N1 seems to be spreading among farms in California and given the fact that these outbreaks on farms are being discovered in large part due to bulk testing of raw milk from farms,” Jennifer Nuzzo, director of the Pandemic Center at Brown University, told the Los Angeles Times. 

“What we don’t know is how much risk H5N1 poses to people that drink unpasteurized, infected milk.” 

Only the “H5” part of the virus was detected in the collected sample, but health officials still believe that it is still likely contaminated with H5N1. No H5 cases have been reported in the state and it hasn’t been identified in any cows either. 

Mark McAfee, owner of Raw Farm, told the Los Angeles Times that this is the first time any of his products have tested positive for the virus since he started enrolling in voluntary testing in April.

But it’s not the first time Raw Farm has accidentally placed contaminated products on the market. In February, the company had to issue a recall of its raw cheddar cheese products that were linked to an E. coli outbreak across multiple states. The dairy company was also tied to a salmonella outbreak in October 2023 that infected at least 165 people.

Nuzzo told the Los Angeles Times that findings from recent animal studies indicate that the bird flu virus “could pose a risk if ingested in large enough quantities, but we have not yet seen human cases resulting from raw milk consumption. Given that ingestion of raw milk has no credible health benefits, I personally would avoid drinking it.”

Just last week, a child was reported to have contracted the bird flu – the first youth case in California. Investigators still aren’t sure how he caught it, but have ruled out contact with infected dairy – including raw milk – or poultry animals. 

So far, the Golden State has seen 29 positive cases, all in dairy workers except for the child. Only 55 cases of bird flu have been reported nationwide, with California making up about half of all cases. 

The virus has also been detected in wastewater sites in Santa Clara County, including Palo Alto, San Jose, Gilroy, and Sunnyvale.

It’s also been found in 24 of California’s 28 wastewater systems, according to testing from WastewaterScan.

States across the country have recently been legalizing raw milk products. President-elect Donald Trump’s Health and Human Services nominee Robert F. Kennedy Jr. has also indicated that he wants to increase the nation’s access to and consumption of raw milk.