Australia notifies first case of High Pathogenicity Avian Influenza H5N1 in a wild bird

On 20 June 2026, WOAH was notified of the first detection of high pathogenicity avian influenza (HPAI) H5N1 in Australia in a marine wild bird, a migratory brown skua (Stercorarius antarcticus). The virus is related to H5N1 HPAI clade 2.3.4.4b viruses, which is the same subtype that is predominantly circulating in poultry, wild birds, and mammals globally. Enhanced general and targeted surveillance is underway by the animal health authorities to determine the extent of infection. An epidemiological investigation has commenced.

HPAI H5N1 has caused a global panzootic since 2021, affecting wild birds, poultry, and multiple mammalian species. Until recently, Australia remained free of this particular subtype despite widespread international incursions.

Since its emergence, this H5N1 subtype has crossed continents, reaching North and South America in 2022 and extending to the Antarctic islands in 2023. It has since been detected in new host species such as cattle, and marine mammals, caused sporadic human infections, driven exceptionally high activity in wild birds in 2025, and is now being reported in Australia for the first time.

The World Organisation for Animal Health (WOAH) acknowledges Australia’s immediate notification of Influenza A virus of high pathogenicity in non-poultry birds through the World Animal Health Information System (WAHIS) and commends Australia for its longstanding commitment to transparency and to the protection of global animal health.

This notification represents a significant epidemiological event, documenting the first detection of HPAI H5N1 in a wild bird in Australia. The finding confirms the incursion of this globally circulating virus lineage into wildlife in a subregion that had remained free from this subtype despite its extensive international spread in other regions and sub-regions. The risk for Australian avifauna, especially endemic bird species is significant.

This detection underscores critical considerations: