A person in the United States has been reported as the first known human to die from the rare H5N5 strain of bird flu, though health officials say the risk to the general public remains low.
The victim was an older adult from Grays Harbor County in Washington state who had underlying health conditions. According to the Washington State Department of Health, the individual was hospitalized in early November after developing a high fever, confusion and respiratory symptoms.
Health officials said the person kept a backyard flock of domestic poultry that had been exposed to wild birds, which is believed to be the source of the infection. They confirmed that no other people linked to the case have tested positive and that there is no evidence of human-to-human transmission.
The US Centers for Disease Control and Prevention previously stated that this case did not increase the overall public health risk. Officials said they will continue monitoring close contacts of the individual as a precaution.
H5N5 is not considered more dangerous to humans than the better-known H5N1 strain, which caused around 70 human infections across the US in 2024 and 2025, mostly involving mild illness in poultry and dairy farm workers.
The difference between the two strains relates to a viral protein that affects how the virus exits infected cells and spreads to nearby cells.
