Another Michigan dairy worker has been diagnosed with bird flu, the third human case associated with an outbreak in U.S. dairy cows, health officials said Thursday.
The patient reported a cough and eye discomfort, unlike the other two workers, who had only eye symptoms, health officials said. The farmworker was quickly provided antivirals and is recovering from respiratory symptoms, Michigan health officials said.
The risk to the public remains low, although farmworkers exposed to infected animals are at higher risk, health officials said. The Michigan cases occurred on different farms and there are no signs of spread among people, officials said.
“Risk depends on exposure, and in this case, the relevant exposure is to infected animals,” the U.S. Centers for Disease Control and Prevention said in a statement.
In late March, a farmworker in Texas was diagnosed in what officials called the first known instance globally of a person catching this version of bird flu from a mammal.
Last week, Michigan officials announced the first case there. That worker developed eye symptoms after “a direct splash of infected milk to the eye,” Michigan health officials said in a statement.
Workplace risk for dairy farmers
Neither of the Michigan workers was wearing face shield or other personal protective equipment, which “tells us that direct exposure to infected livestock poses a risk to humans, and that PPE is an important tool in preventing spread among individuals who work on dairy and poultry farms,” Dr. Natasha Bagdasarian, the chief medical executive of Michigan’s health department, said in a statement.
Angela Rasmussen, a virologist at the Vaccine and Infectious Disease Organization (VIDO) at the University of Saskatchewan, studies H5N1.
“H5N1 is a clear occupational risk to dairy workers and this highlights the importance of detecting new cases as early as possible, so we can understand how to reduce risks to both cows and the people who are working with them,” Rasmussen said.
“In Canada, it’s important we remain vigilant for introduction to cattle here, for the safety of cows and the milk supply, as well as the safety of workers and producers.”
There is no evidence that the risk to the general population has increased in Canada, Rasmussen added.
Not in Canadian milk supply
Health Minister Mark Holland told reporters on Thursday that Canada has no cases of H5N1 in cows and none has been found in the commercial milk supply.
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.
As of Thursday, H5N1 has been confirmed in 66 dairy herds in nine states, according to the U.S. Agriculture Department.
Michigan will soon begin testing dairy farm workers for signs of prior infection with avian flu, a county health official told Reuters.
The new case marks the fourth 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, Colo. His only symptom was fatigue, and he recovered. That predated the virus’s appearance in cows.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.
