A person in Texas has been diagnosed with bird flu, an infection tied to the recent discovery of the virus in dairy cows, health officials said Monday.
The patient was being treated with an antiviral drug and their only reported symptom was eye redness, Texas health officials said. Health officials say the person had been in contact with cows presumed to be infected, and the risk to the public remains low.
It marks the first known instance globally of a person catching this version of bird flu from a mammal, federal health officials said.
However, there’s no evidence of person-to-person spread or that anyone has become infected from milk or meat from livestock, said Dr. Nirav Shah, principal deputy director of the Centers for Disease Control and Prevention.
Genetic tests don’t suggest that the virus suddenly is spreading more easily or that it is causing more severe illness, Shah said. And current antiviral medications still seem to work, he added.
Last week, dairy cows in Texas and Kansas were reported to be infected with bird flu — and federal agriculture officials later confirmed infections in a Michigan dairy herd that had recently received cows from Texas. None of the hundreds of affected cows have died, Shah said.
Since 2020, a bird flu virus has been spreading among more animal species – including dogs, cats, skunks, bears and even seals and porpoises – in scores of countries.
However, the detection in U.S. livestock is an “unexpected and problematic twist,” said Dr. Ali Khan, a former CDC outbreak investigator who is now dean of the University of Nebraska’s public health college.
This bird flu was first identified as a threat to people during a 1997 outbreak in Hong Kong. More than 460 people have died in the past two decades from bird flu infections, according to the World Health Organization.
Most infected people got it directly from birds, but scientists have been on guard for any sign of spread among people.
Texas officials didn’t identify the newly infected person, nor release any details about what brought them in contact with the cows.
The CDC does not recommend testing for people who have no symptoms. Roughly a dozen people in Texas who did have symptoms were tested in connection with the dairy cow infections, but only the one person came back positive, Shah said.
It’s only the second time a person in the United States has been diagnosed with what’s known as Type A H5N1 virus. In 2022, a prison inmate in a work program picked it up while killing infected birds at a poultry farm in Montrose County, Colorado. His only symptom was fatigue, and he recovered.