A Second Dairy Worker Has Contracted Bird Flu, C.D.C. Reports

A farmworker in Michigan has been diagnosed with bird flu, state officials announced on Wednesday, making it the second human case associated with the outbreak in cows.

Officials said that the individual became infected with the virus, called H5N1, after exposure to infected livestock. The individual had only mild symptoms and has fully recovered, officials said. They did not provide additional details in order to protect the privacy of the farm and farmworker, they said.

In 2022, a person in Colorado with direct exposure to infected poultry became the first confirmed human case of H5N1 in the United States. Last month, the Centers for Disease Control and Prevention reported an H5N1 infection in a Texas dairy farm worker — the first case associated with the outbreak in cows.

The detection of this latest case did not suggest that bird flu was widespread in people, officials said, adding that the risk to the general public remained low.

“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.

Still, the case suggests that as more herds are infected, farmworkers continue to be at elevated risk of bird flu. “This case was not unexpected,” said Dr. Nirav Shah, principal deputy director of the C.D.C.