Second case of human bird flu linked to dairy cows in U.S.
Wang Jimin
May 23, 2024
[New Sancai Compilation First Release] A dairy worker in Michigan has been diagnosed with avian influenza, the second human case linked to an outbreak in U.S. dairy cows.
The male worker had been exposed to dairy cows on a farm with infected animals. When U.S. and Michigan health officials announced the case on May 22, they said he had mild eye symptoms and had recovered.
Officials from the U.S. Centers for Disease Control and Prevention said the person's nasal swab tested negative, but an eye swab on May 21 tested positive for avian influenza, "suggesting an eye infection."
Dr. Natasha Bagdasarian, Michigan's chief medical executive, said the worker experienced a "hard feeling" in his eye earlier this month, but it was a very mild case.
Health officials say the risk to the population remains low, but farm workers exposed to infected animals are at higher risk. They say these workers should be provided with protective gear, especially eye protection.
Health officials said they don't know if the Michigan farmworkers were wearing protective glasses, but the investigation is ongoing.
In late March, a Texas farmworker was diagnosed with the world's first known case of avian influenza contracted from a mammal. The patient reported only eye inflammation and recovered.
Since 2020, avian influenza viruses have spread among more animal species in dozens of countries, including dogs, cats, skunks, bears, and even seals and porpoises.
Its detection in U.S. livestock earlier this year was an unexpected turn, raising questions about food safety and whether it could start spreading among humans.
This is not happening despite an increasing number of reported cases of infection in dairy cows. As of May 22, the virus has been confirmed on 51 dairy farms in nine states, according to the USDA. Fifteen of the herds are located in Michigan.
Dr. Nirav Shah of the CDC said the case was "not unexpected" and that more cases of infection may be diagnosed in people who work around infected cows.
U.S. officials said they have tested 40 people since the first case in a dairy cow was discovered in late March. Baghdadsarian told The Associated Press in an interview that Michigan has tested 35 of them.
Shah praised Michigan officials for aggressively monitoring farm workers. Health officials there sent daily text messages to workers who came into contact with infected cows asking about possible symptoms, an effort that helped officials detect the infection, he said. He said no other workers reported symptoms.
That's encouraging news, said Michael Osterholm, an epidemiologist at the University of Minnesota who has studied bird flu for decades. So far, there is no indication that the virus is causing flu-like illness or is spreading from person to person. "If we have four or five people with severe respiratory illness, we will take action," he said.
High levels of the virus have been found in raw milk from infected cows, but government officials say pasteurized products sold in grocery stores are safe because heat treatment has been shown to kill the virus.
The new case marks the third person in the United States diagnosed with the H5N1 virus. In 2022, a prison inmate in a work program contracted the virus when he killed infected birds at a poultry farm in Montrose County, Colorado. His only symptom was fatigue, from which he later recovered. This predates the emergence of the virus in cattle.
(Compiled by: Wang Jimin)
(Editor: Jiang Qiming)
(Source of the article: Compiled and published by New Sancai)
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