Detection and spread of high pathogenicity avian influenza virus H5N1 in the Antarctic Region

• Published in: Nature communications Vol. 15; no. 1; pp. 7433 - 11
• Main Authors: Banyard, Ashley C., Bennison, Ashley, Byrne, Alexander M. P., Reid, Scott M., Lynton-Jenkins, Joshua G., Mollett, Benjamin, De Silva, Dilhani, Peers-Dent, Jacob, Finlayson, Kim, Hall, Rosamund, Blockley, Freya, Blyth, Marcia, Falchieri, Marco, Fowler, Zoe, Fitzcharles, Elaine M., Brown, Ian H., James, Joe
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03-09-2024; Nature Publishing Group; Nature Portfolio
• Subjects: 38/90; 45; 45/77; 45/88; 49; 59; 631/158/1469; 631/326/596/1578; 64; 692/700/478/174; 704/158/672; Animals; Antarctic Regions; Antarctic zone; Aptenodytes patagonicus; Arctocephalus gazella; Avian flu; Birds - virology; Eudyptes chrysocome; Fulmarus glacialis; Gallus gallus domesticus; Garrodia nereis; Gene sequencing; Host range; Human motion; Human populations; Humanities and Social Sciences; Influenza; Influenza A Virus, H5N1 Subtype - genetics; Influenza A Virus, H5N1 Subtype - isolation & purification; Influenza A Virus, H5N1 Subtype - pathogenicity; Influenza in Birds - epidemiology; Influenza in Birds - transmission; Influenza in Birds - virology; Introduced species; Islands; Larus dominicanus; Leucocarbo atriceps; Leucocarbo atriceps georgianus; Mammals; Mammals - virology; Migratory birds; Migratory species; Mirounga leonina; Motion perception; multidisciplinary; Pathogenicity; Pathogens; Phalacrocorax magellanicus; Phylogeny; Population genetics; Populations; Science; Science (multidisciplinary); Seals; Seals (animals); Seals, Earless - virology; Stercorarius antarcticus; Sterna vittata; Tachyeres brachypterus; Thalassarche melanophris; Turdus falcklandii; Viruses; Antarctic Regions; United Kingdom > UK; Falkland Islands; South Georgia; Antarctic region
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-51490-8

Until recent events, the Antarctic was the only major geographical region in which high pathogenicity avian influenza virus (HPAIV) had never previously been detected. Here we report on the detection of clade 2.3.4.4b H5N1 HPAIV in the Antarctic and sub-Antarctic regions of South Georgia and the Falkland Islands, respectively. We initially detected H5N1 HPAIV in samples collected from brown skuas at Bird Island, South Georgia on 8th October 2023. Since this detection, mortalities were observed in several avian and mammalian species at multiple sites across South Georgia. Subsequent testing confirmed H5N1 HPAIV across several sampling locations in multiple avian species and two seal species. Simultaneously, we also confirmed H5N1 HPAIV in southern fulmar and black-browed albatross in the Falkland Islands. Genetic assessment of the virus indicates spread from South America, likely through movement of migratory birds. Critically, genetic assessment of sequences from mammalian species demonstrates no increased risk to human populations above that observed in other instances of mammalian infections globally. Here we describe the detection, species impact and genetic composition of the virus and propose both introductory routes and potential long-term impact on avian and mammalian species across the Antarctic region. We also speculate on the threat to specific populations following recent reports in the area.
High pathogenicity avian influenza virus has a wide host range and has been detected across a large geographic area. Here, the authors present evidence of spread to the Antarctic and sub-Antarctic regions, with signs of clinical infection and positive virus detection in birds and elephant seals.