A resident of Washington state, who was an older adult with pre-existing health conditions, is believed to be the first person to have succumbed to a rare strain of bird flu, according to a statement from the Washington State Department of Health. The individual was being treated for H5N5, a strain of bird flu, marking what appears to be the first known human infection of this strain.
The individual hailed from Grays Harbor County, located approximately 78 miles southwest of Seattle. They owned a backyard flock of domestic poultry that had been exposed to wild birds, as per health officials. Despite the unfortunate incident, state health officials have reassured the public that the risk remains low.
The statement from the health department emphasized, “The risk to the public remains low. No other people involved have tested positive for avian influenza.” Health officials are closely monitoring anyone who had close contact with the individual. However, they have found no evidence of transmission of this virus between people.
Earlier this month, the Centers for Disease Control and Prevention (CDC) issued a statement about the infection. The CDC stated that there was no information to suggest that the risk to public health had increased as a result of this case.
The H5N5 strain is not considered to pose a greater threat to human health than the H5N1 virus. The latter was responsible for a wave of 70 reported human infections in the US in 2024 and 2025. Most of these cases were mild illnesses in workers on dairy and poultry farms.
The difference between H5N5 and H5N1 lies in a protein involved in releasing the virus from an infected cell and promoting spread to surrounding cells.