Long-Distance Avian Migrants Fail to Bring 2.3.4.4b HPAI H5N1 Into Australia for a Second Year in a Row

• Published in: Influenza and Other Respiratory Viruses
• Main Authors: Wille, Michelle, Atkinson, Robyn, Barr, Ian G., Burgoyne, Charlotte, Bond, Alexander L., Boyle, David, Christie, Maureen, Dewar, Meagan, Douglas, Tegan, Fitzwater, Teagan, Hassell, Chris, Jessop, Roz, Klaassen, Hiske, Lavers, Jennifer L., Leung, Katherine K.S., Ringma, Jeremy, Sutherland, Duncan R., Klaassen, Marcel
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2024
• Subjects: Antarctic; Antarc*
• Online Access: https://pure.uhi.ac.uk/en/publications/81108613-1547-4da7-8d6f-1779fe41612d; https://doi.org/10.1111/irv.13281; http://www.scopus.com/inward/record.url?scp=85189526241&partnerID=8YFLogxK; http://www.scopus.com/inward/citedby.url?scp=85189526241&partnerID=8YFLogxK

The current high-pathogenicity avian influenza (HPAI) H5N1 lineage 2.3.4.4b panzootic is having a profound impact on the poultry industry and wildlife [1, 2]. HPAI H5N1 emerged in poultry in 1996 and has caused outbreaks in wild bird populations episodically since 2005 [3], with the epidemiology of the virus changing substantially with the emergence of new lineages. A novel lineage emerged in 2014 (2.3.4.4), which has diversified and caused substantial mortality, including mass mortality events, of wild birds in 2014, 2016 and 2020–present, marine mammals since 2023, as well as ongoing outbreaks in poultry, globally [3]. Understanding the changing phenotype and viral incursion risk following the emergence of novel lineages of HPAI is of crucial importance for the development of short-term and long-term mitigation strategies to protect wildlife, livestock and humans alike. Wild birds, particularly waterfowl, were initially implicated in the long-distance spread of HPAI and have been predominantly implicated in the re-occurring incursions into Europe and Africa [4]. However, recent viral incursions, such as that to the sub-Antarctic islands, and expansion, such as the movement of HPAI down the spine of South America [5], were driven by seabirds, suggesting that the long-distance dispersal of lineage 2.3.4.4b HPAI is no longer waterfowl dependent (e.g., [2, 6]). Lineage 2.3.4.4b has now been detected on all continents except Oceania [7]. HPAI incursion risk to Australia has previously been considered low due to the absence of waterfowl species that migrate beyond the Australio-Papuan region [8] and from influenza genomic surveillance [9]. In turn, annually, millions of migratory seabirds and shorebirds migrate from Asia and North America to Australia (Figure 1). Some of these species have been shown to be part of the avian influenza reservoir community [10], have been infected by HPAI and potentially survive and move HPAI viruses [11].