Joint FAO/OIE/WHO Preliminary Risk Assessment Associated with Avian Influenza A(H3N8) Virus

Overview

The Chinese health authority reported an influenza A(H3N8) infection in a 4-year-old boy from Henan Province on 25 April 2022 to the World Health Organization (WHO). No human infection with influenza A(H3N8) virus had been recorded before this case. Genetic analysis of the virus confirmed it is of avian origin. Avian influenza A(H3N8) viruses are commonly found - but not associated with disease - in wild birds; such viruses have also been detected in live poultry markets in Asia. Occasionally, A(H3N8) viruses have been associated with disease in dogs, horses, pigs, donkeys, and most recently seals. However, the genetic composition of A(H3N8) viruses detected in animals to date is different from that detected in the patient.