Distribution and Characterisation of Tick-Borne Flavi-, Flavi-like, and Phenuiviruses in the Chelyabinsk Region of Russia

Abstract

In this work, we presented data from a two-year study of flavi-, flavi-like, and phenuiviruses circulation in the population of ixodid ticks in the Chelyabinsk region. We isolated three tick-borne encephalitis virus (TBEV) strains from <i>I. persulcatus</i>, which was not detected in the ticks of the genus <i>Dermacentor</i>. The virus prevalence ranged from 0.66% to 2.28%. The Yanggou tick virus (YGTV) is widespread in steppe and forest-steppe zones and is mainly associated with ticks of the genus <i>Dermacentor</i>. We isolated 26 strains from <i>D. reticulatus</i>, <i>D. marginatus</i>, and <i>I. persulcatus</i> ticks in the HAE/CTVM8 tick cell line. The virus prevalence ranged from 1.58% to 4.18% in <i>D. reticulatus</i>, ranged from 0.78% to 3.93% in <i>D. marginatus</i>, and was 0.66% in <i>I. persulcatus</i>. There was combined focus of TBEV and YGTV in the territory of the Chelyabinsk region. The Alongshan virus (ALSV) was found to be associated with <i>I. persulcatus</i> ticks and is spread in forest zone. We detected 12 amplicons and isolated 7 strains of ALSV in tick cells. The virus prevalence ranged from 1.13% to 6.00%. The phlebovirus Gomselga and unclassified phenuivirus Stavropol were associated with <i>I. persulcatus</i> and <i>D. reticulatus</i> ticks, respectively. Virus prevalence of the unclassified phenuivirus Stavropol in the Chelyabinsk region is lower than that in neighbouring regions.