H5N1 Bird Flu Reaches Every Continent as Australia Confirms First Case

Australia confirmed its first-ever case of H5N1 high pathogenicity avian influenza on Friday, announcing that the deadly virus strain had been detected in a brown skua seabird found at Cape Le Grand National Park near Esperance, Western Australia — approximately 700 kilometres south-east of Perth. The confirmation, made by the CSIRO Australian Centre for Disease Preparedness, means the H5N1 virus has now reached every continent on Earth for the first time in history.

How the Case Was Identified

The brown skua — a large, migratory seabird — was found dead at the national park. Tissue samples were collected and sent to the CSIRO laboratory, which confirmed the presence of the clade 2.3.4.4b H5N1 lineage, the same strain that has been sweeping through Europe, the Americas, and — since 2024 — Antarctica. A second bird found at the same location, a southern giant petrel, is also suspected to have been infected.

Global Significance

Australia had been the last inhabited continent where H5N1 had not yet been detected. The virus first emerged in Asia in the 1990s and has since become an unprecedented global panzootic, infecting and killing millions of wild and domestic birds on every landmass. Its arrival in Australia raises concerns for the country's unique wildlife and its significant poultry industry. Poultry company Inghams immediately moved to a state of "high biosecurity vigilance."

Human Risk Remains Low

Australian health authorities stressed that the risk to humans from this particular detection remains very low, as the virus was found in a wild seabird and there is no evidence of spread to domestic poultry or any human exposure. Authorities are monitoring the situation and have increased surveillance of wild bird populations around the discovery site.