US reports first human case of H5N5 bird flu

An older adult, who was hospitalised with influenza symptoms in early November, has been confirmed to have influenza A H5, a type of avian influenza.

Additional testing shows the virus to be H5N5, an avian influenza virus that has previously been reported in animals but never before in humans.

The Centers for Disease Control and Prevention (CDC) and DOH currently consider the risk to the public from avian influenza to be low.

Domestic poultry or wild birds are the most likely source of virus exposure; however, a public health investigation is ongoing, the Washington State Department of Health said.

The Washington State Department of Health is working with the local health department and the Washington State Department of Agriculture to complete exposure and animal health investigations, it said.

According to the government department, Avian influenza is a disease caused by influenza type A viruses, which naturally occur in wild aquatic birds around the world. These viruses can infect other bird species, and, occasionally mammals, and can be deadly to domestic birds such as chickens and turkeys. On rare occasions, avian influenza viruses can infect people and make them sick.

Most cases have occurred in people who were exposed to sick or infected animals. Reported human cases of avian influenza in the United States have ranged from mild to severe, with one fatality.

The risk of avian influenza increases in the fall and winter because migratory birds can carry the virus and spread it to domestic animals including commercial poultry farms and backyard flocks.

Transmission of avian influenza between humans is extremely rare and has never been documented in the United States. To ensure that human-to-human spread is not occurring, public health officials are contacting anyone who has been in close contact with the patient to monitor for symptoms and provide testing and treatment as needed.