Blue Avian Flu Virus Stock Photo

Influenza A virus subtype H5N1 (A H5N1) is a subtype of the influenza A virus, which causes influenza (flu), predominantly in birds. It is enzootic (maintained in the population) in many bird populations, and also panzootic (affecting animals of many species over a wide area).A H5N1 virus can also infect mammals (including humans) that have been exposed to infected birds in these cases, symptoms are frequently severe or fatal.