Health officials in Washington state have reported what is believed to be the first human death caused by the rare H5N5 strain of bird flu. Authorities emphasized that the overall risk to the public remains low.
The victim, an older adult with underlying health conditions, had been hospitalized since early November after developing a high fever, respiratory problems and confusion. According to the Washington State Department of Health, the person lived in Grays Harbor County and kept a backyard flock of poultry that had been exposed to wild birds.
Officials said no other individuals who were involved in caring for the flock or who had close contact with the patient have tested positive. They confirmed there is no evidence of human-to-human transmission.
The Centers for Disease Control and Prevention also stated that this case does not indicate an increased threat to public health.
H5N5 is not considered more dangerous to humans than H5N1, the strain responsible for about 70 human infections in the US across 2024 and 2025, most of which were mild cases among farm workers. The key difference between the two strains lies in a protein that affects how the virus spreads between cells.
