US officials on Thursday reported the country’s third human case of bird flu linked to the current outbreak of the virus in dairy cattle.
The Michigan farm worker is the second person sickened by the disease in the Midwestern state, following a first case in Texas in April.
The Centers for Disease Control and Prevention (CDC) stated said that all three cases were spread from cows to humans, as opposed to human-to-human, which would be more concerning.
However, it noted this was the first case “to report more typical symptoms of acute respiratory illness associated with influenza virus infection,” while the previous cases had mild symptoms like conjunctivitis.
The person’s symptoms included a cough without fever, eye discomfort, and watery eye discharge. They were treated with the antiviral medicine oseltamivir and isolated at home, with symptoms resolving.
The worker did not wear personal protective equipment, which health authorities recommend for those in close contact with dairy herds, according to Michigan’s health department.
In recent years, a highly pathogenic avian influenza virus called HPAI H5N1 has spread to infect more than 50 animal species, including dairy cattle in the United States since March.
Unlike in Europe, American farmers are allowed to feed cattle ground-up chicken waste, which some scientists say may be a risk factor for bird flu, though the feed industry disputes this, and US authorities believe wild birds are responsible for infecting cows.
“The risk to members of the general public who do not have exposure to infected animals remains low,” said the CDC.
CDC advises precautionary measures amid proactive testing in Michigan
In addition to using PPE, people should avoid close exposure to sick or dead animals, including wild birds, domesticated birds, and other domesticated animals, according to the CDC.
They should also avoid touching animal excrement or bedding, or consuming unpasteurized milk, the agency added.
Recent testing has confirmed mice are sickened by exposure to raw milk contaminated with bird flu, but pasteurization destroys the virus.