United States reports second human bird flu case linked to dairy cattle

A person in the United States is recovering from bird flu after being exposed to dairy cattle, officials said Monday amid rising concern over the current global strain of the virus.

It is only the second case of a human testing positive for bird flu in the country, and comes after the infection sickened herds in Texas, Kansas and several other states over the past week.

“The patient reported eye redness (consistent with conjunctivitis), as their only symptom, and is recovering,” said the Centers for Disease. They were told to isolate and are being treated with the antiviral drug used for the flu.

The CDC added the infection does not change its bird flu human health risk assessment for the US general public, which it rates as low.

The first US bird flu case in a human occurred in a Colorado prison inmate in 2022 — however, that was through infected poultry.

Experts are worried about the increasing number of mammals infected by the current H5N1 strain of Highly Pathogenic Avian Influenza (HPAI) and its potential for spread between mammals, even as cases among humans remain highly rare.

“Initial testing has not found changes to the virus that would make it more transmissible to humans,” the US Department of Agriculture, the CDC, and the Food and Drug Administration said in a joint statement last week, which added the cows were infected by wild birds.

The Texas health department said the cattle infections do not present a concern for the commercial milk supply, as dairies are required to destroy milk from sick cows. Pasteurization also kills any viruses.

It added it was working to provide guidance to affected dairies about how to minimize workers’ exposure, and how people who work with affected cattle should monitor for symptoms and get tested.

The findings marked the first time ever that HPAI has been detected in dairy cattle, according to the American Veterinary Medical Association. On March 20, Minnesota reported bird flu cases among juvenile goats.

“The detection of HPAI, first in goats and now in dairy cattle, underscores the importance of adherence to biosecurity measures, vigilance in monitoring for disease, and immediately involving your veterinarian when something seems ‘off,’” said AVMA President Rena Carlson in a recent statement.

Bird flu killed a polar bear in Alaska last fall, according to state officials, and has killed hundreds of thousands of marine mammals in South America, according to the Scientific Committee on Antarctic Research.