Epidemiological situation of Avian Influenza in Ukraine during 2020–2021

Abstract

Avian influenza viruses (AIVs) are spread globally by wild migratory birds that are reservoirs of AIVs. Epidemics of highly pathogenic avian influenza (HPAI) can devastate the poultry industry and result in severe trade restrictions. Many routes of wild migratory birds pass through the territory of Ukraine, therefore studying the circulation of the viruses is important for the prevention of AIV spreading. The aim of the investigation was to summarize and analyze results of AI tests carried out by state laboratories during 2020–2021. The tests were conducted in the framework of state control of AI aimed to early detection and prevention of HPAI virus spreading on the territory of Ukraine. 27 354 samples of biological material from wild and domestic birds (11 115 samples – in 2020 and 16 239 – in 2021) were tested by PCR in State Scientific and Research Institute of Laboratory Diagnostics and Veterinary and Sanitary Expertise and regional state laboratories. For PCR testing commercial kits and reagents were used: IndiSpin Pathogen Kit (INDICAL BIOSCIENCE), VetMAX™-Gold AIV Detection Kit (Thermo Fisher Scientific), AIV H5-H7 REAL TIME (ADIAVET), AgPath-ID™ One-Step RT-PCR Reagents (Ambion) with N8 RT-PCR primers and probe. In 2020, 84 positive samples on AI type A subtype H5N8 from poultry of Vinnytsia, Kherson, Kyiv and Mykolaiv oblasts was detected. In 2021, the presence of AIV RNA subtype H5N8 and H5N1 was detected in 87 samples (72 samples from poultry, 11 from wild birds and 4 from zoo birds) of Mykolaiv, Kyiv, Donetsk, Ternopil and Kherson oblasts. In 2020, 9 outbreaks of AI were registered in Vinnytsia (1), Mykolaiv(5), Kyiv (2) and Kherson (1) oblasts; in 2021, 11 outbreaks were registered in Mykolaiv (4), Kyiv (2), Donetsk (2), Ternopil (1) and Kherson (2) oblasts. In general, during 2020–2021, 20 outbreaks of AI subtype H5 (3 – commercial poultry farms, 13 – from backyards, 3 – in wild birds and 1 – in zoo birds) were registered in 6 oblasts of Ukraine. RNA of AIV in the samples from imported birds was not detected. Wild migratory birds are the most likely source of AIV in Ukraine since most outbreaks were registered in oblasts located at the crossing of wild bird migratory routes.