When it comes to bird flu in milk or dairy products, what's safe to consume?

If a cow has bird flu, the virus is shed into its milk.
(Adobe Stock photo)

The spread of bird flu in U.S. dairy herds along with the Department of Agriculture's new raw milk testing requirements may leave consumers unsure about which milk is safe. Dani Blum and Alice Callahan of The New York Times answer questions about why testing is needed, what bird flu's presence in cow's milk means for humans and pets, and how Americans can keep themselves and their families healthy while still enjoying cow's milk and milk products.

Is pasteurized milk safe?
Yes. "Federal health agencies have stressed that the commercial supply of pasteurized milk is safe," the Times reports. "Multiple studies have demonstrated that pasteurization, the process of heating milk for a short period of time, inactivates the virus."

Why do officials want to test unpasteurized milk?
On Dec. 16, 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," Blum and Callahan explain. "Farmers and dairy processors will also have to provide milk samples if the government requests them." Testing will help officials more accurately pinpoint where the virus is active and trace its spread. 

How much of the virus might be in raw milk?
A lot. If a cow is infected with bird flu, high concentrations of the virus are present in its milk. "The virus can survive in refrigerated, unpasteurized milk for up to five weeks, according to a study published in May in the New England Journal of Medicine," Blum and Callahan add. 

Can you get bird flu from drinking raw milk?
To date, there haven't been any documented cases of bird flu infections linked to humans consuming raw milk. "We don’t have enough data yet to say whether humans can contract avian influenza from drinking raw milk, said Dr. Keith Poulsen, the director of the Wisconsin Veterinary Diagnostic Laboratory," the Times reports. 

Like raw milk, raw milk products that contain bird flu haven't been linked to people contracting the virus, but scientists are still unsure if it's a possibility; however "the Food and Drug Administration has also repeatedly warned about the risks of drinking raw milk [and raw milk products] in general. That’s because unpasteurized milk can harbor bacteria like salmonella, listeria and campylobacter," Blum and Callahan write. "These pathogens can lead to food-borne illnesses, which can cause serious health issues or even be deadly for certain high-risk populations."

Raw milk or raw milk products containing bird flu can sicken pets. Cats are particularly vulnerable to the virus and have died after consuming it.

Bird flu is also known as: H5N1 and avian influenza