Abstract Title
Avian influenza at the wild bird and poultry interface in Australia
Abstract
Australia experienced its largest HPAI outbreaks in farmed poultry in 2024, resulting in the destruction of approximately 1.5 million birds. H7N3 HPAI affected mixed free-ranged and caged layer chicken farms in the state of Victoria. Outbreak response tracing also detected H7N9 HPAI in Victoria. Concurrently, an H7N8 HPAI affected farms in New South Wales and the Australian Capital Territory. These HPAI viruses emerged from separate spillovers of low pathogenicity H7 avian influenza viruses (AIV) that have circulated as a single lineage in Australia for at least 50 years. H9 and H10 AIVs also circulate in local wild birds with sporadic detections in poultry and other birds in domestic settings. There is also evidence of virus exchange between wild shorebird and waterfowl host orders. In 2024, we detected H9N2 AIV in wild birds and poultry and in northern and southern Western Australia as well as from the Coral Sea, indicating wide distribution. Infrequent but multiple incursions of H9 and H10 viruses into Australia from the global AIV pool have been detected. H10 AIV detected in Australia since 2023 was introduced more recently around 2020 through Asia from a broader North American lineage, replacing a previously circulating lineage. AIVs of subtypes H7, H9 and H10 are of particular interest as Asian lineages have caused repeated zoonotic infections. An isolated H10 spillover event in poultry abattoir workers has also previously been reported in Australia. The current circulation of these viruses in Australia, genetic reassortment dynamics and their interface spillover impacts will be presented.
Co-Author(s)
Frank Y. K. Wong, CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia.
Guy Weerasinghe, Northern Australia Quarantine Strategy, Department of Agriculture, Fisheries and Forestry, Darwin, Northern Territory, Australia.
Andrew C. Breed, Epidemiology, Surveillance and Laboratory Section, Department of Agriculture, Fisheries and Forestry, Canberra, Australia Capital Territory, Australia.
Jeff Butler, CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia.
Matthew J. Neave, CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia.
Abstract Category
Notable outbreaks, field and molecular epidemiology, and surveillance in poultry