Occurrence and Genetic Diversity of Kemerovo Virus in Ixodid Tick of Western Siberia

Kemerovo virus (KEMV), a member of Reoviridae family, Orbivirus genus, is transmitted by ixodes ticks and can cause the damage of human central nervous system. The occurrence and genetic diversity of KEMV in Western Siberia still remained poorly studied, so, the aim of this work was to investigate the prevalence and genetic variability of KEMV in ixodid ticks from Western Siberia. A total of 1958 Ixodes persulcatus, I. pavlovskyi ticks and their hybrids from Novosibirsk and Omsk provinces, Altai Republic (Russia) and East Kazakhstan province (Kazakhstan) were analyzed for the presence of KEMV and tick-borne encephalitis virus (TBEV) RNA. It was shown that KEMV distribution area in Western Siberia was wider and included Northern and Northeastern Altai in addition to Omsk and Novosibirsk provinces. For the first time this virus was found in Kazakhstan. The occurrence of KEMV was statistically lower than TBEV in most locations in Western Siberia. KEMV was found both in I. persulcatus and I. pavlovskyi ticks and in their hybrids. Notably, KEMV variants found in 2010s genetically differ from those isolated in 1960s. Moreover, the possibility of reassortment for KEMV was demonstrated for the first time.