biostudies-literatureWille MAustralia Research CouncilSurveillance ProgramAustralian Government Department of Agriculture, Fisheries and ForestryAustralian Government Department of HealthThe WHO Collaborating Centreveae076https://www.ebi.ac.uk/biostudies/studies/S-EPMC11482279biostudies-literatureUnknown10(1)The current panzootic of high pathogenicity avian influenza virus H5N1 demonstrates how viral incursions can have major ramifications for wildlife and domestic animals. Herein, we describe the recent incursion into Australia of two low pathogenicity avian influenza virus subtypes, H4 and H10, that exhibited contrasting evolutionary dynamics. Viruses detected from national surveillance and disease investigations between 2020 and 2022 revealed 27 genomes, 24 of which have at least one segment more closely related to Eurasian or North American avian influenza lineages than those already circulating in Australia. Phylogenetic analysis revealed that H4 viruses circulating in shorebirds represent a recent incursion from Asia that is distinct from those circulating concurrently in Australian wateVirus evolutionContrasting dynamics of two incursions of low-pathogenicity avian influenza virus into Australia.PMC11482279DE200100977 DP190101861Crawley AStevens VBreed ACFord MRead AJO'Dea MLatimore SMartin SBroz IFrost MNeave MJBarr IGWong FYKBan de Gouvea Pedroso SCherrington TO'Riley KKlaassen MKirkland PDThayaparan SZufan SGrillo VHolmes ECWille MLynch SEGrimsey JFarrugia BMee PTMatereke CfalseContrasting dynamics of two incursions of low-pathogenicity avian influenza virus into Australia.The current panzootic of high pathogenicity avian influenza virus H5N1 demonstrates how viral incursions can have major ramifications for wildlife and domestic animals. Herein, we describe the recent incursion into Australia of two low pathogenicity avian influenza virus subtypes, H4 and H10, that exhibited contrasting evolutionary dynamics. Viruses detected from national surveillance and disease investigations between 2020 and 2022 revealed 27 genomes, 24 of which have at least one segment more closely related to Eurasian or North American avian influenza lineages than those already circulating in Australia. Phylogenetic analysis revealed that H4 viruses circulating in shorebirds represent a recent incursion from Asia that is distinct from those circulating concurrently in Australian wate2024-01-01T00:00:00Z20242026-06-30T03:09:53.533Z2025-04-04T02:54:26.265ZS-EPMC114822793941628610.1093/ve/veae076