first Human Death Linked to Rare H5N5 Bird Flu Strain Confirmed in Washington State
Grays Harbor County, Washington – Health officials have confirmed the first known human death linked to the H5N5 strain of avian influenza in the United States. The patient, a resident of Grays Harbor County, had been hospitalized since early November with symptoms including a high fever, confusion, and respiratory problems, according to a statement released by the Washington State Department of Health.
This marks the first recorded fatality associated with the H5N5 strain, which, while similar to the more prevalent H5N1 virus, differs in a protein crucial for viral spread. The case is particularly noteworthy as the individual had a backyard flock of domestic poultry exposed to wild birds, suggesting a potential source of infection. While the risk to the public is currently considered low, the incident underscores the ongoing threat of avian influenza and the potential for novel strains to emerge.
Health officials report that no other individuals involved have tested positive for the virus.They are actively monitoring those who had close contact with the deceased,but currently,there is no evidence of human-to-human transmission. The Centers for Disease Control and Prevention (CDC) previously stated that this single case did not indicate an increased risk to public health.
The H5N5 strain is not currently believed to pose a greater threat to humans than the H5N1 virus, which has caused 70 reported human infections in the US during 2024 and 2025, primarily mild illnesses among workers in the dairy and poultry industries. The key distinction between the two strains lies in a protein that facilitates the virus’s release from infected cells and its ability to spread.
