As cases of the bird flu virus are on the rise in the US, it has now been detected in raw milk from a California dairy farm sold in stores.

Public health officials in Santa Clara County announced that a sample of raw milk from Fresno-based Raw Farm tested positive for the H5 virus on Sunday. The farm is the largest producer and retailer of dairy in the Golden State.

However, the Los Angeles Times reports that the officials believe it was contaminated with the bird flu, H5N1, as it has not been identified in any cows.

Jennifer Nuzzo, director of the Pandemic Center at Brown University told the outlet, “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 on raw milk from farms.”

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

As a result of the findings, Raw Farm has voluntarily recalled all quart and half-gallon milk products it produced on November 9 that are set to expire on Nov. 27 and have lot ID No. 20241109.

There haven’t been any reported cases of bird flu involving Raw Farm products.

To be safe, the dairy farm is requesting that stores remove its products from their shelves and has urged consumers to return theirs for a free replacement or refund.

This comes a few days after a California child was diagnosed with bird flu, the first reported case in a US minor. Health officials confirmed the case on Friday.

Thankfully, the Centers for Disease Control and Prevention confirmed that the child had only mild symptoms. The child was treated with antiviral medication and has since been recovering. The only details released about the child are that they live in Alameda County, which includes Oakland and Berkeley, and attend daycare.

Dr Tomás Aragón, the state’s public health director, said, “It’s natural for people to be concerned, and we want to reinforce for parents, caregivers and families that based on the information and data we have, we don’t think the child was infectious – and no human-to-human spread of bird flu has been documented in any country for more than 15 years.”

The latest infection brings the total reported number of US bird flu cases to 55 this year, including 29 in California, the CDC said. The flu has been spreading throughout the US in wild birds, poultry and other animals over the last few years.

It has killed around 280 million poultry birds since 2021, causing the largest sudden loss of the world’s wild birds in decades. The H5N1 virus has even spread as far as Antarctica – which led to mass deaths of elephant seals and fur seals.

Bird flu began spreading through US dairy cattle in March 2024. California is America’s top dairy producer, so it’s no surprise that it’s become the centre of the outbreak. The state has detected 402 infected herds since August, which is 65% of the total 616 herds confirmed with the virus spread over 15 states.