Washington State Reports First Human Fatality from H5N5 Avian Influenza

A resident of Grays Harbor County, Washington, has died from complications associated with H5N5 avian influenza, according to the Washington State Department of Health. This case represents the first known human fatality from this particular strain globally. The individual, an older adult with underlying health conditions, had been hospitalized in King County since early November.

The patient maintained a backyard flock of mixed domestic birds, which had potential exposure to wild birds. Environmental testing detected the avian influenza virus within the flock's surroundings, suggesting that contact with domestic poultry, their environment, or wild birds was the probable source of infection.

Health officials emphasize that the risk to the general public remains low. No other individuals associated with this case have tested positive for avian influenza. Public health authorities are monitoring those who had close contact with the patient for any symptoms, and there is currently no evidence of human-to-human transmission of this virus.

The Centers for Disease Control and Prevention (CDC) has confirmed the H5N5 infection and stated that there is no indication that this case increases the risk to public health. H5N5 is not considered a greater threat to human health than the H5N1 virus, which was responsible for approximately 70 reported human infections in the United States during 2024 and 2025, most of which were mild illnesses among workers on dairy and poultry farms.

Health authorities advise individuals with backyard poultry to avoid contact with sick or dead birds and to report any illness in poultry to the Washington State Department of Agriculture. Additionally, it is recommended that people who may be exposed to domestic or wild birds receive a seasonal flu vaccine to reduce the risk of concurrent infections with human and avian influenza viruses.