Avian influenza

Fact sheet - Health conditions directory

Avian influenza, or 'bird flu', is an infectious viral disease caused by influenza type A viruses.

There are many types of influenza A viruses that usually only infect birds; these are called avian influenza viruses (AIV). AIV is commonly found in wild aquatic birds, such as waterfowl and shorebirds and infection can occur among domestic poultry such as chickens, ducks or turkeys. Highly pathogenic avian influenza (HPAI) is associated with severe disease and mortality in birds. Viruses that cause only mild disease are called low pathogenic avian influenza (LPAI).

Some AIV, such as H7, H5 and H9 subtypes, are associated with sporadic zoonotic human infection. Human infection of H5 or H7 subtypes are more commonly associated with severe disease and mortality. Human cases of avian influenza are usually associated with direct or indirect exposure to live or dead infected birds or their contaminated environment.

As of 2019, 2,644 human cases of avian influenza, mainly H7N9 or H5N1 subtypes have been reported. Limited person to person transmission of avian influenza has occurred however, continued transmission is low risk. The potential for AIV to cause severe disease in humans or mutate to spread easily among humans is closely monitored by animal and human health authorities.

• Read Communicable Diseases Network Australia guidelines

Notification

World Organisation for Animal Health information system – Latest avian influenza outbreak information

Global Influenza Programme Human-Animal interface - Risk assessment summaries and situation reports for influenza at the human-animal interface

CDC Influenza Risk Assessment Tool - Support for the risk assessment of avian influenza viruses with pandemic potential