The third case of bird flu infecting a human has been recorded, and it is the second linked to the presence of bird flu in dairy cows.
The Michigan farmworker who suffered what state health authorities described as mild symptoms came into contact with infected cows, The New York Times reported Wednesday.
In 2022, one person in Colorado who worked with infected poultry was infected with H5N1 in the United States. Last month, a Texas dairy farm worker was infected.
Bird flu has been found in52 dairy herds in nine states, a number suspected of being an undercount. Traces of the virus causing bird flu have been found in samples of milk sold in 17 states, according to the U.S. Food and Drug Administration.
The virus has been mutating, with mutations the Times said “may make it more adept at spreading between species.”
“This virus is being closely monitored, and we have not seen signs of sustained human-to-human transmission at this point,” Dr. Natasha Bagdasarian, Michigan’s chief medical executive, said in a statement.
“This case was not unexpected,” said Dr. Nirav Shah, principal deputy director of the federal Centers for Disease Control and Prevention.
The Times said veterinarians have reported flu-like symptoms in farm workers but few have been tested. The CDC said it has tested about 40 people.
However, federal agencies are already preparing 4.8 million doses of a vaccine to fight H5N1, officials said.
Although officials said there is no sign of human-to-human transmission, one expert said that does rule out such transmission, according to NBC News.
"I don’t think this changes the risk picture in terms of the virus being transmitted to people and then transmitted among people," said Michael Osterholm, an infectious disease expert and director of the Center for Infectious Disease Research and Policy at the University of Minnesota.
"I wouldn't be surprised if we saw five, six, 10 cases in the next few weeks," Osterholm said.
“It’s likely that there will be several cases that emanate from exposure to infected cows and their milk amongst farm workers,” Amesh Adalja, an infectious disease expert at the Johns Hopkins Center for Health Security, said, according to the U.K.'s Guardian.
“The key thing is to make sure that testing is wide enough to capture them,” Adalja said.
According to the U.K.'s Daily Mail, four pet cats have died from bird flu, with two in South Dakota that had no connection with dairy farming.
“The development could be significant because it suggests the virus is edging closer to humans,” the outlet reported.
Beth Thompson, the state veterinarian of South Dakota, said no one knows how the cats were infected because there are no livestock on the property.
The other two cats that died lived on dairy farms in Michigan.
