The first confirmed human infection with H5N5 avian influenza has been reported, resulting in the death of an older adult exposed to a backyard flock. While authorities stress that overall public risk remains low, this historic case has drawn renewed attention to poultry biosecurity and disease surveillance.

Health officials reported that the individual, a resident of Grays Harbor County, Washington State, had underlying health conditions and was receiving treatment before passing away on 21 November. Environmental sampling around the backyard flock tested positive for H5N5, indicating domestic poultry or wild birds as the likely source of exposure. No other flock contacts or close human contacts have tested positive.

Authorities emphasized that there is no evidence of human-to-human transmission of this H5N5 strain. Public health teams are monitoring individuals who had contact with the patient or the flock environment for potential symptoms. Despite the fatality, officials maintain that the risk to the general public remains low.

This marks the first documented human infection with the H5N5 subtype. While H5 viruses circulate widely in wild birds, human cases are extremely rare and typically linked to close, unprotected contact with infected poultry or contaminated environments. The case highlights the importance of strengthened One Health surveillance and robust biosecurity measures for both commercial and backyard flocks.