Risk of avian influenza to animals that scavenge on infected carcasses

Highly pathogenic avian influenza viruses of subtype H5N1 have circulated for over two decades following its emergence in Southeast Asia. Various reassortment events, driven by rapid global spread and evolution of the virus, has led to ongoing outbreaks in wild bird in all continents except Oceania. The virus frequently spills over into terrestrial and marine mammals and has sustained transmission in European fur farms, dairy cattle in the USA and marine mammals in South America. Wild birds, particularly migratory shorebirds, have enabled H5N1 to reach South America and Antarctica for the first time. An outbreak of H5N1 in Australia appears imminent. Scavenging species are at risk of spillover infection because of consumption of carcasses that contain high levels of influenza virus. We highlight the threat the virus poses to Australia’s native scavenging species, the wider ecosystem, and the likely entry points of the virus.