First Human Fatality from Rare Bird Flu Strain Confirmed
Health authorities in Washington state have reported what is believed to be the first human death from a rare strain of avian influenza known as H5N5. The individual, an older adult from Grays Harbor County with pre-existing health conditions, had been undergoing treatment after becoming the first known human infected with this specific virus.
Details of the Case and Source of Exposure
The resident, who lived approximately 78 miles (125 kilometers) southwest of Seattle, maintained a backyard flock of domestic poultry. State health officials confirmed that these birds had been exposed to wild birds, which is considered the likely source of the infection. The Washington State Department of Health emphasized that no other individuals have tested positive for this avian influenza strain following the case.
Public Health Risk Assessment and Monitoring
In an official statement released on Friday, health officials were quick to reassure the public. The risk to the general population is considered low, and there is no evidence of person-to-person transmission of this virus. Authorities are monitoring individuals who had close contact with the deceased but have found no further spread.
This assessment aligns with a recent statement from the Centers for Disease Control and Prevention (CDC), which indicated that this single case does not suggest an increased public health threat. The H5N5 virus is not currently viewed as a greater danger to human health than the more common H5N1 virus, which was responsible for numerous mild infections among U.S. dairy and poultry workers in 2024 and 2025.
The primary distinction between H5N5 and H5N1 lies in a specific protein that affects how the virus is released from an infected cell and spreads to surrounding cells.
