The role of the greater white-fronted goose, Anser albifrons (Scopoli, 1769) (Anseriformes: Anatidae) in maintaining the natural circulation of the influenza A virus in the northwestern part of Black Sea Region (Ukraine)

The publication combines the results of ornithological observations of the greater white-fronted goose, Anser albifrons (Scopoli, 1769) during migration and wintering in the south-western part of Odesa Region of Ukraine (Bilhorod-Dnistrovskyi, Izmail, and Bolhrad districts) and the results of laboratory tests of biological samples of this species for the presence of the influenza A pathogen. The study was conducted in 2017–2019. A total of 1,591 samples of biological material (feces) of the greater white-fronted goose, collected in 48 locations in Odesa Region, were examined using polymerase chain reaction (PCR). The influenza A virus genome was detected in 23 samples. The total annual prevalence was 1.44%, in winter — 1.44%, in spring — 1.81%. During the fall migration, no influenza A virus was detected in the genome samples, which determines the wintering period as the most important stage of integration of the greater white-fronted goose in maintaining the natural circulation of influenza A in the study area. By year, the prevalence was distributed as follows: in 2017 — 1.75%, in 2018 — 1.97%, in 2019 — 0.78%. All cases of detection of influenza A virus genome in fecal samples of the greater white-fronted geese concerned areas near large bodies of water in the coastal part of the Black Sea (Sasyk Lagoon and Tuzly Lagoons). Among the factors that may determine the high involvement of the greater white-fronted goose in the circulation of influenza A in these areas are the presence of other sources of infection: numerous dense multi-species aggregations of birds in the wetland complex and favorable conditions for pathogen transfer