Traces of bird flu have been detected in pasteurized milk — leaving many people wondering if it’s safe to drink.
The U.S. Food and Drug Administration (FDA) released a notice on Thursday stating that one in five retail samples of commercial milk tested positive for fragments of highly pathogenic avian influenza (HPAI), more commonly known as bird flu or avian flu.
The share of milk with viral remnants was higher in areas where herds of cattle had been infected.
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The presence of the virus in the milk doesn’t necessarily mean there is a risk to consumers, however, the FDA noted.
"Additional testing is required to determine whether an intact pathogen is still present and if it remains infectious, which would help inform a determination of whether there is any risk of illness associated with consuming the product," the agency stated.
"Although bird flu viruses do not normally infect humans, sporadic human infections have occurred," the FDA stated in the alert.
Before milk can be sold commercially, government regulations require that it is pasteurized.
During the pasteurization process, raw milk is heated to a certain temperature for a brief period of time and is then chilled again, according to the International Dairy Foods Association (IDFA) website.
This process kills any pathogens and ensures that milk is safe to drink.
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Dr. Scott Pegan, professor of biomedical sciences at the University of California, Riverside and a biochemist for the United States Medical Research Institute of Chemical Defense, said the FDA’s finding does not mean there is any direct risks to consumers.
"In the U.S., commercial intrastate sold milk is required to be pasteurized," he told Fox News Digital. "This process is geared to kill viruses like H5N1 and other bacteria that can pose a threat to human health."
"Milk that has been pasteurized is safe and there is no current reason to avoid it or other pasteurized milk products based on the FDA’s findings," Pegan went on.
"However, there is a substantial risk of consuming unpasteurized milk and products of that milk."
Even after viruses and bacteria have been killed in pasteurized milk, remnants can remain in the milk, he said — but they are not dangerous.
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Edward Liu, M.D., chief of infectious diseases at Hackensack Meridian Jersey Shore University Medical Center in New Jersey, agreed that there is not a risk associated with drinking pasteurized milk.
"The pasteurization is the key — the heat treatment kills off the viruses," he told Fox News Digital. "Although the FDA’s testing picked up fragments [of the virus], the heating process destroyed it, so it’s not able to infect people."
The fragments alone are not enough to cause any kind of infection, he confirmed.
"I think the key word is ‘fragments.’ Just like with COVID, if you do a PCR test a month later, we'll detect little fragments of the virus, but it's not active anymore," Liu said.
"So if the virus isn’t entirely intact, it shouldn't be able to infect you."
Any sporadic cases of human infection would likely occur when a farmer is handling birds directly, Liu said.
"There are some people who like to go all natural, but pasteurization has been used for decades for safety," he said. "Some degree of processing is actually better and safer for us."
The "indirect concern" within the scientific and medical community involves the increased risk of "spillover" to humans from animals with the H5N1 virus, said Pegan.
"Prior to the outbreak in dairy cattle, this concern principally revolved around the risk of transmission to humans from wild birds or poultry," he told Fox News Digital.
"The presence of H5N1 avian flu in the milk of these cattle shows that cattle may be able to provide a new reservoir for this virus, increasing the odds of exposure to those in direct contact with the infected cattle."
The more animals that are infected, the higher chance that humans may come in direct contact with the virus — which likely would lead to a greater number of human cases, said Pegan.
"The case of cattle-to-human transmission seen in Texas is in line with this concern," he noted.
"Also, the more mammals infected increases the chances that the virus will adapt to other mammals, such as humans."
The FDA restated its "long-standing recommendation" that consumers avoid drinking raw milk that has not been pasteurized.
The agency also recommends that companies refrain from manufacturing or selling raw milk or raw milk products made with milk from cows that tested positive for bird flu, were exposed to the virus or showed symptoms of illness.
"Over the past few years, there has been an increased consumer demand for these unpasteurized products," Pegan said.
"While not allowed to be sold via interstate brands, some states have relaxed local sales of these products at farmer's markets and similar outlets," he said.
"Individuals may want to avoid those unpasteurized products until more information is obtained about this H5N1 avian flu outbreak in dairy cattle."
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The FDA also urged producers to "take precautions" when discarding milk from affected cows, "so that the discarded milk does not become a source of further spread."
So far, only one person has been confirmed to have contracted the virus after exposure to infected cows, the FDA stated.
"The CDC says the risk to the general public remains low," the agency said.
"The FDA and USDA continue to indicate that, based on the information we currently have, our commercial milk supply is safe."
Fox News Digital reached out to the National Milk Producers Federation, the American Dairy Association and the International Dairy Foods Association for comment.
