Serological monitoring of Influenza A among wild and domestic ungulates in Ukraine

Abstract

The article provides a brief historical background of equine influenza, the spread of this disease worldwide, and the current epizootic situation. The results of serological monitoring by ELISA of wild and domestic ungulates from different farms and regions of Ukraine for the presence of antibodies to influenza A viruses are presented. Blood serum samples from 372 domestic horses and 32 wild ungulates were tested. Samples from animals collected in 2023 and 2024 and archival blood serum samples from 2021 were used and tested according to the manufacturer’s instructions using ELISA test systems manufactured by IDEXX, INGEZIM, and IDVet. The data obtained indicate a fairly active circulation of influenza A viruses in populations of unvaccinated domestic horses. The circulation was established not only in recent years (2023–2024, seroprevalence from 10% to 100%), but was observed earlier, as evidenced by the detection of 60.9% of positive samples in samples collected in 2021. In addition, two out of three positive samples were found in wild horses from Kherson Region, which indicates the circulation of influenza A virus among wild animals and requires further investigation. The results correlate with the worsening of the epidemiological situation regarding influenza in animals in Europe. The subsequent phase of the research is serotyping, which involves determining the presence of antibodies to specific virus subtypes by hemagglutinin