Influenza A virus

**Definition:** The type species of the genus ALPHAINFLUENZAVIRUS that causes influenza and other diseases in humans and animals. Antigenic variation occurs frequently between strains, allowing classification into subtypes and variants. Transmission is usually by aerosol (human and most non-aquatic hosts) or waterborne (ducks). Infected birds shed the virus in their saliva, nasal secretions, and feces.

**Tree numbers:** - B04.820.480.968.405.400

**Synonyms:** - Human Influenza A Virus - Influenza Virus Type A - FLUAV - Influenza Viruses Type A - Orthomyxovirus Type A