US health officials have reported what is believed to be the first human death caused by the rare H5N5 strain of bird flu. The case involved an older adult in Washington state who had underlying health conditions, and authorities say the overall risk to the public remains low.
The individual, from Grays Harbor County, was hospitalized in early November after developing a high fever, confusion and breathing difficulties. Health officials confirmed the patient was infected with the H5N5 avian influenza virus.
Investigators said the person kept a backyard flock of poultry that had been exposed to wild birds, which is believed to be the source of the infection. No other people linked to the case have tested positive, and there is currently no evidence that the virus can spread from person to person.
The US Centers for Disease Control and Prevention stated earlier that this case does not indicate an increased risk to public health. Authorities said they are monitoring close contacts as a precaution.
H5N5 is not thought to pose a greater risk to humans than the better-known H5N1 strain, which has caused dozens of mostly mild infections in US farm workers over the past two years. The key difference between the two strains lies in a viral protein that affects how the virus spreads between cells.
