Avian Influenza A(H5N1) – United States of America

Situation at a Glance
The World Health Organization (WHO) was notified about a laboratory-confirmed case of human infection with an influenza A(H5N1) virus on 1 April 2024 by the United States of America IHR National Focal Point (NFP). The patient developed symptoms on 27 March and had a history of exposure to dairy cattle (cows) presumed to be infected with influenza A (H5N1) virus. This is the first human infection with A(H5N1) acquired from contact with infected cattle and the second confirmed human case of influenza A(H5N1) detected in the country. No additional associated cases of human infection with influenza A(H5N1) have been identified. Since the virus has not acquired mutations that facilitate transmission among humans and based on available information, WHO assesses the public health risk to the general population posed by this virus to be low and for occupationally exposed persons, the risk of infection is considered low-to-moderate.