ETIDIOH - NEW

Abstract High pathogenicity avian influenza (HPAI) H5N1 2.3.4.4b poses a substantial conservation threat to ecosystems , populations, and species globally, with its continued spread into new regions increasing concern for potential ecological consequences . During surveys in February-March 2025, we confirmed the virus presence at the southern extent of its known range along the Western Antarctic Peninsula, with recorded mortalities in South Polar Skuas Stercorarius maccormicki on distinct islands in Marguerite Bay , as well as one confirmed and one suspected case in Kelp Gulls Larus dominicanus . At the time of sampling, no evidence of infection was observed in other seabird or mammal species. Consistent with previous global reports, skuas - here, South Polar Skuas - appear particularly vulnerable, yet broader impacts on the local seabird and mammal community remain unclear. Additionally, our use of rapid antigen tests (VDRG AIV Ag Rapid kit 2.0 Median Diagnostics) in the field demonst...

Abstract Since 2020, the outbreak of highly pathogenic avian influenza (HPAI) virus clade 2.3.4.4b has turned into the largest documented panzootic to date , reaching the sub-Antarctic region and Antarctica via the tip of South America in 2023. Here, we describe its recent arrival into the Indian Ocean sub-Antarctic archipelagos of Crozet and Kerguelen , where we first detected the virus in October 2024 in dead southern elephant seals, king penguins, gentoo penguins, brown skuas and kelp gulls . While the panzootic is ongoing, it has already caused unprecedented and alarming mortalities of southern elephant seals. We collected brain swabs from various seal and bird carcasses, subsequently isolated the virus and obtained 25 novel HPAI H5N1 clade 2.3.4.4b sequences. Our phylogenetic and phylogeographic analyses show that there have been independent introductions of the virus to Crozet and Kerguelen, from the distant South Georgia Islands in the Southern Atlantic , and not from the more n...

Abstract Whole-genome analysis of the earliest-detected High Pathogenicity Avian Influenza Virus (HPAIV) H5N1 clade 2.3.4.4b detected in Hannah Point, Antarctica (January 2024) reveals close relatedness to strains that circulated in pinnipeds and seabirds along the Atlantic coast of South America during the second half of 2023. Source: BioRxIV,  https://www.biorxiv.org/content/10.1101/2024.12.29.630510v1?rss=1 _____