Australia's H5N1 defences breached as deadly bird flu arrives via migratory seabirds

Australia has detected highly pathogenic H5N1 clade 2.3.4.4b—the dangerous strain circulating globally—in a seabird near Esperance, WA and on Heard Island in November. The detections suggest ongoing transmission from migratory routes rather than isolated incidents. Public health risk remains low, but Australia's $3.5 billion poultry industry now faces serious biosecurity pressure as agencies respond.