Cow Illness Spreading in US States Sparks Concerns About Milk

A positive human case of the avian flu at a Texas dairy farm is sparking concern across the country about milk supply among cows.

According to the Center for Disease Control (CDC), avian influenza or bird flu is a disease "caused by infection with avian influenza Type A viruses." These viruses can also naturally spread among wild aquatic birds worldwide and can infect domestic poultry and other bird and animal species.

According to the Texas Department of State Health Services (DSHS) on Monday, a human case of avian influenza A(H5N1) virus in the state was identified in a person who had direct exposure to dairy cattle who were presumed to be infected.

"The patient, who experienced eye inflammation as their only symptom, was tested for flu late last week with confirmatory testing performed by the Centers for Disease Control and Prevention over the weekend. The patient is being treated with the antiviral drug oseltamivir," DSHS said in a statement.

According to the CDC, this is the second human case of H5N1 ever recorded in the country. However, there is no current evidence to suggest the virus is being spread among humans.

As a result of the reported case, a public health expert is speaking out about the virus. Rick Bright, the former director of the Biomedical Advanced Research and Development Authority (BARDA), previously cautioned that avian flu could pose a serious threat as he wrote in a 2023 Think Global Health column about the concern that it might become transmissible between humans.

"They would have to do a lot of testing before I would drink milk from one of these farms at this point," Bright told Politico on Monday.

Newsweek has reached out to Bright via the Milken Institute email for comment.

Caitlin Rivers, an epidemiologist at the Johns Hopkins Center for Health Security, was a bit skeptical about the milk and said it would be still be vital to understand whether the virus is changing in a way that makes it more adaptable to spread among humans.

"I don't necessarily suspect that to be the case because I don't think cows are particularly like humans in that way," she told Politico. "But any time the epidemiology of a virus changes it makes me listen more closely."

However, the U.S. Food and Drug Administration (FDA) said it's not aware of milk or food products from symptomatic cows entering interstate commerce, adding that there is "no concern about the safety of the commercial milk supply" because of pasteurization, which heats milk to a temperature that would kill the virus.

Dairy farms are legally required to only supply milk from healthy animals and, on top of this, the pasteurization process helps kill viruses and bacteria.

In an emailed statement to Newsweek, DSHS reiterated on Monday afternoon that "milk from sick cows is required to be destroyed and is not sold. Pasteurization also kills avian flu viruses."

Monday's reported case comes after recent cow infections were found in Idaho, Michigan, Ohio and New Mexico.

Cows also tested positive for the illness last week in the panhandle of Texas area known as Cattle Country. Meanwhile, the CDC, FDA and U.S. Department of Agriculture (USDA) said the virus was found in a Michigan dairy herd that had recently received cows from herds in Texas.

Despite similar concerns over the milk supply, the USDA said in a statement regarding the positive cases, "At this stage, there is no concern about the safety of the commercial milk supply or that this circumstance poses a risk to consumer health."

The CDC has said while it considers HPAI A(H5N1) viruses to have the potential to cause severe disease in infected humans, it considers the human health risk to the U.S. public to be low.

"Although human infections with HPAI A(H5N1) virus are rare, having unprotected exposure to any infected animal or to an environment in which infected birds or other animals are or have been present can pose a risk of infection," the CDC said in a press release.