The monitoring and molecular epizootiology of porcine epidemic diarrhea in Ukraine during 2014-2018

The rapid spread of porcine epidemic diarrhea (PED) in different countries in a short time while and the significant economic damage caused by it were important reasons for conducting long-term monitoring studies in Ukraine. PED monitoring researches conduct carry out during 2014-2018 using RT-PCR and ELISA showed the presence of infection in 14 (66.67%) of 21 examined regions of Ukraine. For the period 2014- 2018, the proportion of PED cases rate was the lowest in 2017 (1.76%) and the highest in 2016 (48.03%). Over the entire period, the percentage seropositive animals progressively decreased to a seronegative status indicator defined in sows in 2018. The results of determination of the virulence of 40 strains of PED virus from different regions of Ukraine using the RT-PCR method proved the circulation of highly virulent strains. The phylogenetic analysis demonstrated that the endemic strain of PED virus is included in the cluster of North American strains and the Chinese strains. Important is the fact that it is not included in the group of European low- virulent S-INDEL strains. Thus, the obtained data indicate a high probability that the PED virus was introduced into Ukraine from the territory of the Asian continent or the United States of America (a high probability that the PED virus was translocated from the territory of the Asian continent or the United States of America into Ukraine).