A man in the United States is severely ill after being infected with a strain of avian influenza, known as H5N5, that has never before been detected in humans.
Patient Details and Symptoms
The patient, described as an older man with underlying health conditions, was admitted to hospital earlier this month. He presented with a high fever, confusion, and respiratory distress. As of last week, he remains hospitalised and is receiving treatment.
The man resides in Grays Harbour County, Washington, and kept a mixed backyard flock of domestic poultry. The Washington State Department of Health confirmed that wild birds also had access to the property, making either group the most probable source of the virus exposure.
Ongoing Investigation and Broader Context
Health officials are actively investigating the precise circumstances of how the infection occurred. Crucially, they have confirmed that no one else has tested positive for the H5N5 strain, and there is no evidence of person-to-person transmission at this time.
While H5N1 is a more common strain of bird flu in the US, H5N5 is a distinct subtype, differentiated by a protein on the virus's surface. Since 2022, the US has recorded 71 human cases of H5 bird flu, with most patients experiencing mild symptoms, though one patient from Louisiana died in January.
For context, the UK has recorded 81 confirmed cases of bird flu, with instances found in locations including Cumbria, Lincolnshire, Norfolk, Suffolk, Scotland, and Wales. Experts caution that while the current risk is low, the evolution of viruses can be unpredictable.
