The Distribution of Puumala orthohantavirus Genome Variants Correlates with the Regional Landscapes in the Trans-Kama Area of the Republic of Tatarstan

Abstract

In the European part of Russia, the highest number of hemorrhagic fever with renal syndrome (HFRS) cases are registered in the Volga Federal District (VFD), which includes the Republic of Tatarstan (RT). Puumala orthohantavirus (PUUV) is the main causative agent of HFRS identified in the RT. The goal of the current study is to analyze the genetic variations of the PUUV strains and possible presence of chimeric and reassortant variants among the PUUV strains circulating in bank vole populations in the Trans-Kama area of the RT. Complete S segment CDS as well as partial M and L segment coding nucleotide sequences were obtained from 40 PUUV-positive bank voles and used for the analysis. We found that all PUUV strains belonged to RUS genetic lineage and clustered in two subclades corresponding to the Western and Eastern Trans-Kama geographic areas. PUUV strains from Western Trans-Kama were related to the previously identified strain from Teteevo in the Pre-Kama area. It can be suggested that the PUUV strains were introduced to the Teteevo area as a result of the bank voles’ migration from Western Trans-Kama. It also appears that physical obstacles, including rivers, could be overcome by migrating rodents under favorable circumstances. Based on results of the comparative and phylogenetic analyses, we propose that bank vole distribution in the Trans-Kama area occurred upstream along the river valleys, and that watersheds could act as barriers for migrations. As a result, the diverged PUUV strains could be formed in closely located populations. In times of extensive bank vole population growth, happening every 3–4 years, some regions of watersheds may become open for contact between individual rodents from neighboring populations, leading to an exchange of the genetic material between divergent PUUV strains.

Analysis of Puumala orthohantavirus Genome Variants Identified in the Territories of Volga Federal District

“…The location of the Kurlan–Mullovka and Barysh subclades were identical on all three phylogenetic trees. On all trees, a well-supported Kurlan–Mullovka subclade is clustered with previously identified strains from the Western Trans-Kama area of the RT [ 22 ], whilst the Barysh group strains PUUV/Barysh/MG_1769/2019 and PUUV/Barysh/MG_1770/2019 formed an independent subclade with good support. At the same time, the location of subclade Varaksino on the phylogenetic trees differed.…”

“…Based on the phylogenetic analysis of PUUV S, M, and L segment sequences obtained from the bank voles captured in the ULR and UR of the VFD, we propose the existence of three genetically distinct sub-lineages of PUUV strains within the RUS genetic lineage (Sub-lineages I, II, and III). Strains in sub-lineage I are commonly found in the Pre-Kama and Trans-Kama areas of the RT [ 21 , 22 ], including parts of the ULR located on the left bank of Volga River and Samara region. These strains demonstrate high genetic identity of nucleotide and aa sequences along the territories of the left bank of the Volga River.…”

“…In our previous works, the PUUV strains’ genetic variability in the Pre-Kama and Trans-Kama areas of the RT were investigated [ 21 , 22 ]. Nevertheless, little is known about the genetic diversity of the PUUV strains in the other VFD territories.…”

Special Issue: ‘Pathogenesis of Emerging Zoonotic Viral Infections’

“…In another original study by Davidyuk et al, the genetic diversity of Puumala orthohantavirus (PUUV) in the Republic of Tatarstan (RT) was analyzed [ 13 ]. PUUV primarily causes a hemorrhagic fever with renal syndrome (HFRS) in the RT, which is one of the most active endemic regions in Russia.…”

“…All PUUV strains were of the RUS genetic lineage and formed two subclades: the Western and Eastern Trans-Kama. PUUVs from Western Trans-Kama were similar to the Teteevo strain from the Pre-Kama clade [ 13 ]. These results suggest that the Teteevo Pre-Kama strain could have been introduced from Western Trans-Kama by the migration of bank voles.…”