WASHINGTON: A Washington state resident has been hospitalized with H5N5 bird flu, marking the first known human case of this strain anywhere in the world. Health authorities say the patient, an older adult with underlying medical conditions, remains severely ill but is receiving specialized care. The US public health community is closely monitoring the situation as experts emphasize the virus’s unpredictable evolution—while also reassuring that the overall public risk remains low.
Rare H5N5 infection confirmed after severe respiratory symptoms
Health officials reported that the patient first sought care in Grays Harbor County after developing high fever, confusion, and severe breathing difficulties in early November. They were later transferred to a specialty hospital in King County for advanced treatment.
Laboratory testing confirmed the presence of H5N5, a bird flu subtype previously detected in animals but never before identified in humans. Historically, nearly all human bird flu cases have involved the H5N1 strain.
Key details confirmed by Washington health officials
- First human case of H5N5 globally
- Patient owns a backyard poultry flock and had recent exposure to wild birds
- Two birds in the flock died of unknown illness
- No secondary human cases detected so far
- Public health risk remains low, according to CDC and state authorities
How the patient may have been infected
Investigators believe the infection is likely linked to close contact with domestic poultry and wild birds, including exposure to bird droppings, saliva, or handling a bird that had died. Since this case was identified, health officials have monitored and tested all individuals who had contact with the patient. No other infections have been detected.
Experts warn of unpredictable viral evolution
While health authorities have emphasized that H5N5 does not appear more infectious or severe than other strains, virologists stress that influenza viruses frequently mutate.
- Dr Angela Rasmussen, a leading virologist in Canada, noted that the emergence of H5N5 in humans reinforces the virus’s unpredictable nature.
- Dr William Schaffner, an infectious disease expert, characterized the case as a likely “rare one-off event” with no evidence of broader public health implications.
Bird flu continues to spread widely among animals across the US
Since January 2022, H5 bird flu has been detected in birds in all US states, affecting an estimated 174 million wild and domestic birds. More than 1,000 dairy herds have also been impacted.
Only 71 human infections have been recorded in the US during this outbreak, including one fatal case in Louisiana. Just four human infections have been confirmed so far this year.
Seasonal migration is also accelerating outbreaks: more than 7 million farmed birds, including 1.3 million turkeys, have been infected since September—raising concerns ahead of Thanksgiving.
Public health risk remains low, CDC says
Despite the headline-grabbing nature of a new bird flu strain in humans, the CDC continues to classify the risk to the general public as low. The agency is closely monitoring people exposed to infected birds or animals and conducting enhanced surveillance nationwide.
