First Human Death Linked to Rare H5N5 Bird Flu Strain in the US

A resident of Washington state is reported to be the first human to succumb to the rare H5N5 strain of bird flu. Health officials announced on Friday that, despite this tragic incident, the risk to the general public is considered low.

The individual, an older adult with existing health issues, had been receiving treatment for the H5N5 strain after being identified as the first known human case of this particular virus. The Washington State Department of Health confirmed that the patient had been hospitalised since early November, presenting symptoms such as high fever, confusion, and respiratory difficulties.

Located in Grays Harbor County, approximately 125 kilometres (78 miles) south-west of Seattle, the individual owned a backyard flock of domestic poultry that had been in contact with wild birds, a common transmission route for avian influenza.

In an official statement, state health officials reassured the community, saying, “The risk to the public remains low. No other individuals involved have tested positive for avian influenza.” They are monitoring anyone who had close contact with the affected individual, but they emphasised that there is no evidence indicating that the virus can be transmitted between people.

Earlier in November, the Centers for Disease Control and Prevention (CDC) had released a statement regarding the infection, clarifying that there was no indication that public health risks had escalated due to this case. The CDC underscored that H5N5 does not pose a greater threat to human health compared to the H5N1 strain, which was responsible for approximately 70 reported human infections in the United States during 2024 and 2025. Most of those cases were mild and primarily involved individuals working on dairy and poultry farms.

The difference between the H5N5 and H5N1 strains lies in a specific protein that plays a crucial role in the virus's ability to exit infected cells and spread to adjacent cells. The public is advised to remain vigilant but calm, as health officials continue to monitor the situation closely and provide updates as necessary.