A person in the United States is believed to be the first human to die from a rare strain of bird flu. The older adult had underlying health conditions and was being treated for the bird flu strain H5N5 after becoming the first known human infected by it, according to a statement issued by the Washington State Department of Health.

US health officials said the risk to the public is low. They said the person who died was from Grays Harbor County near Seattle. The person had kept a flock of domestic poultry which had been exposed to wild birds. Health officials have not said if the person who died was male or female.

In a statement, the health officials said: “The risk to the public remains low. No other people involved have tested positive for avian influenza.”

Health officials said they will monitor anyone who came into close contact with the person, but there was “no evidence of transmission of this virus between people”.

The US Centers for Disease Control and Prevention issued a statement earlier this month about the infection which said no information suggested the risk to public health has increased as a result of this case.

H5N5 is not believed to be a greater threat to human health than the H5N1 virus behind a wave of 70 reported human infections in the US in 2024 and 2025. Most of those infections have been mild illnesses in workers on dairy and poultry farms.

The difference between H5N5 and H5N1 is in a protein involved in releasing the virus from an infected cell promoting the disease’s spread to surrounding cells.

Fifty confirmed cases of H5N1 bird flu have been recorded by the Government since October 1 – 39 in England, one in Scotland, seven in Wales and three in Northern Ireland.

This compares to 81 confirmed bird flu cases last year and six between 2023-24, according to official figures.

H5N1 was confirmed at a poultry farm in Claydon, Suffolk this week, with a surveillance zone declared around the premises.

Bird flu mainly affects birds, but can spread to humans via close contact. The NHS says it can be fatal, but is “very rare” in the UK.

Symptoms of bird flu in people can be mild or severe. These include a high temperature, cough, sore throat, runny or blocked nose, wheezing, sneezing, irritated eyes and a shortness of breath.

Anti-viral medicines are available to treat bird flu, according to the NHS.