Since 2020, a new strain of high pathogenicity avian influenza (HPAI), H5N1 clade 2.3.4.4b, has spread across the world. The new strain, known as H5 avian influenza or H5 bird flu, has caused unprecedented outbreaks of disease in wild birds, wild mammals and some domesticated mammals.
The first case in Australia was detected on 20 June 2026 in a vagrant migratory seabird on the WA south coast.
In the rest of the world, the H5 bird flu has:
- caused severe disease and high death rates in wild birds
- infected more than 560 bird species from more than 25 avian orders
- infected more than 100 species of mammals including seals, sea lions, dolphins, porpoises, dairy cattle, pigs, foxes, cats and dogs
- infected some people who worked closely with infected animals or environments contaminated with bird droppings.
Unlike other strains of avian influenza, H5 bird flu can directly infect poultry with HPAI viruses and cause severe disease immediately (without needing to mutate).
If H5 bird flu establishes in Australian wildlife, it would have significant impacts on our wildlife, agricultural industries and the economy.
Federal, state and local governments, the poultry industry and wildlife stakeholders have been working together to reduce the likely impact of H5 bird flu if it arrived in Australia.
Print this page
