Predicting high pathogenicity avian influenza H5N1 susceptibility in wild birds

Sara Ryding, Tobias A Ross, Marcel Klaassen

High pathogenicity avian influenza (HPAI) has caused widespread sickness and mortality in poultry and wildlife, especially since the emergence of a novel H5 virus belonging to clade 2.3.4.4b in 2021. The ongoing panzootic caused by this lineage has infected an unprecedented diversity of species across the globe, seeming capable of impacting all birds. Here, we analyse outbreak notifications of HPAI in wild birds to understand the impacts of species’ ecologies and phylogeny on HPAI notifications and predict host susceptibility to HPAI H5N1 for Australia, as the only continent thus far unaffected by this virus. We found a significant family-level phylogenetic signal in HPAI notifications in wild birds, showcasing that the panzootic is not impacting all bird groups equally. Furthermore, we found that adding ecological traits to this phylogenetic information does not improve explanatory power of HPAI notifications, presumably because many ecological traits are conserved across members of a family. Using the family-level phylogenies to predict HPAI H5N1 susceptibility in Australian birds, we predict that families of Australian seabirds, shorebirds, and waterbirds will be most susceptible to HPAI H5N1 once it arrives on the continent. Our results provide an empirical indication of species susceptible to HPAI H5N1, which can be used to direct monitoring efforts and disease management globally. With special reference to Australia, our predictions of HPAI H5N1 susceptibility can be used in conjunction with conservation status and other species-specific information to inform preparedness activities, monitoring, and response upon incursion.