Extension of scope of susceptible mammalian species as avian influenza global situation developed in 2023–2024

Introduction. Highly pathogenic avian influenza currently requires the close attention of the international community. Determining the factors affecting transmission and replication of avian influenza virus in mammals and analysing the evolutionary processes involved will suggest which virus lineages will have the spillover potential and infect non-typical hosts, including humans.Objective. The paper is aimed at studying the avian influenza epidemic situation in mammals, description of the features of the avian influenza epizootic process, retrospective analysis of influenza outbreaks in non-typical hosts.Materials and methods. The study was carried out in the Information and Analysis Centre of the Veterinary Surveillance Department of the Federal Centre for Animal Health (Vladimir). The data obtained was based on statistical data from the database of the World Organisation for Animal Health WAHIS and scientific publications of foreign and domestic authors. Cartographic analysis was carried out using ArcGIS geographic information system (ESRI, USA).Results. The avian influenza virus H5N1 epizootic process in 2022–2024 involved mammalians of various families (Bovidae, Mustelidae, Ursidae etc.) in which the disease had not been previously recorded. Strict biosecurity measures and updated alert systems are of crucial importance to effectively prevent the spread of the disease. In a limited number of countries (Bangladesh, Dominican Republic, China, Egypt, Indonesia, Laos, Vietnam, EU countries, etc.), vaccination has been used as a preventive and emergency measure to protect birds from influenza.Conclusion. Transmission of highly pathogenic avian influenza virus to mammals of different species, including livestock, may be the start of a future pandemic. The recently recorded virus spillover indicates emergence of adaptive mutations and poses a threat to animal health, public health, food security and biodiversity.