Ohio’s health department confirmed Saturday that a farmer in the state was discharged from the hospital after being sickened by bird flu, marking the fourth American to have been hospitalized with the H5N1 virus.
“The individual had respiratory symptoms. He was previously hospitalized and has since been released,” a spokesperson for Ohio’s health department told CBS News in an email Saturday.
Authorities in Ohio had previously refused to disclose the status of their bird flu case, which was first announced earlier this week in a man who had contact with sick poultry.
News of the hospitalization comes a day after Wyoming announced the third U.S. hospitalization from bird flu, linked to exposure to an infected backyard flock.
Wyoming’s health department declined Saturday to release details of the patient’s status, who is hospitalized in neighboring Colorado.
“We don’t typically provide information on patient condition due to privacy concerns,” spokesperson Kim Deti said in an email to CBS News.
Deti said that the hospitalization in Colorado occurred within the last two weeks, “just a couple of days” after they had been exposed to sick poultry at their home in Wyoming’s Platte County.
The vast majority of human cases have been blamed on direct, often intensive exposure to sick cows or birds.
Data reported so far by the CDC from testing labs suggests that this winter’s record surge of influenza is being driven by seasonal strains of the virus, not human-to-human spread of a bird flu strain.
However, investigations of a handful of human bird flu cases in the U.S. have so far not been able to identify a source of how they may have gotten sick.
The first U.S. bird flu hospitalization was reported last year in Missouri, though health officials think the patient tested positive while hospitalized for other reasons, not bird flu. A second hospitalization was later reported in Louisiana, in a patient who died from the virus.
Which bird flu strain sickened the new cases?
It is unclear which strain of the H5N1 bird flu virus caused the Ohio and Wyoming cases. Answering that question has been a focus of experts and health officials for previous cases, as they track the evolution of the virus.
Federal authorities usually take samples of the virus and analyze them for worrying mutations that might raise the risk of the virus spreading between humans or causing more severe disease.
A spokesperson for Ohio’s health department said that information was not immediately available. Wyoming has also not confirmed the genotype of their case, though the state’s veterinarian says flocks in the county where the patient lived recently tested positive for the B3.13 strain of the virus.
A Centers for Disease Control and Prevention spokesperson did not immediately respond to a request for comment about whether that had occurred for these cases.
Many human cases of bird flu in the U.S. to date have been in dairy workers after working with sick cows infected by the B3.13 strain of the H5N1 virus.
Scientists suspect that B3.13 is less severe for humans. Until recently, it had been the only bird flu strain detected spreading between dairy herds and into some nearby poultry farms.
But a new strain called D1.1 has grown to dominate the spread between wild migratory birds in recent months. That strain has also contributed to a surge of spillovers from wild birds to poultry flocks that have driven up egg prices nationwide.
D1.1 was also behind the first confirmed U.S. fatality from bird flu, in the Louisiana patient. A child in Canada was also hospitalized with D1.1 last year.
D1.1 has also spread at least twice now in recent weeks from birds to dairy herds, the U.S. Department of Agriculture confirmed Friday, dashing hopes that the spillover which started the B3.13 dairy herd outbreaks in late 2023 was a one-off.
