The patient was only identified as “an older adult with underlying health conditions” and had been hospitalised since early this month, the Washington state department of health said Friday.

Tests conducted by the University of Washington confirmed the patient was suffering from H5N5 avian influenza, the department said in a statement, calling it “the first recorded infection with this variant in a person globally”.

The result was confirmed by the US centers for disease control and prevention.

“The risk to the public remains low. No other people involved have tested positive for avian influenza,” it said. “There is no evidence of transmission of this virus between people.”

The patient has “a backyard flock of mixed domestic birds,” and officials believe this was the source of exposure.

The CDC has recorded more than 70 human cases of bird flu this year. A person died after contracting H5N1 in Louisiana in January.

The World Health Organization has recorded more than 1,000 bird flu cases in humans since 2003 in 25 countries –a figure that includes all strains of the virus.