A U.S. resident who recently was identified as the first person to be infected with the H5N5 variant of highly pathogenic avian influenza (HPAI) died on November 21, the Washington State Department of Health (DOH) reported.
The state agency initially reported on November 14 that the person had tested positive for the H5N5 variant of HPAI, and that was the first confirmed case of H5N5 in a human globally. The samples were tested at the University of Washington Medicine Clinical Virology Lab, and the patient had been receiving treatment at a King County hospital since early November.
“The Washington State Department of Health offers its heartfelt condolences to the person’s family and friends,” DOH said in a press release.
The patient was a resident of Grays Harbor County, and was identified as an older adult with underlying health conditions who had a mixed backyard poultry flock, which had exposure to wild birds. DOH testing identified the HPAI virus in the environment of the flock, making exposure to the domestic poultry, their environment, or wild birds the most likely source of exposure for this patient.
The name, age and gender of the patient was not released.
DOH stated that the public risk remains low, and that no other people have tested positive for H5N5. DOH added that there is no evidence of transmission of this virus between people.
Still, public health officials continue to monitor people who were in close contact with the patient to ensure that human-to-human spread has not occurred.
Prior to this case, all other instances of human avian influenza infections had involved the H5N1 avian influenzas – the same serotype that was present in most U.S. poultry flock infections during the 2022-25 outbreak. Prior to now, the last human case of HPAI in the United States was reported in February. Around the globe, 26 human cases of HPAI were reported between January 1 and August 26, according to the U.S. Centers for Disease Control and Prevention.
View our continuing coverage of the global avian influenza situation.
