Characterization of Powassan viruses from Far Eastern Russia

Abstract

We report the isolation and detailed characterization of the novel strain, Partizansk/2006, of Powassan virus (POWV) from a human case of infection, which occurred in Primorsky krai, Russia, in 2006. Comparative complete genome sequence analysis of the Far Eastern strains Spassk-9 (1975), Nadezdinsk-1991 and Partizansk/2006 of POWV revealed that these strains are 99.8% similar to the LB strain, which was isolated in Canada in 1958. Phylogenetic analysis of 5' UTR sequences of five other strains of POWV isolated from 1972 to 1986 in Primorsky krai produced similar results. Presumably, Far Eastern POWV has common putative ancestor with LB strain POWV from North America, and the time of divergence of these POWVs is relatively short. We conclude that POWV has become endemic in Far Eastern Russia.

Revisiting the Clinal Concept of Evolution and Dispersal for the Tick-Borne Flaviviruses by Using Phylogenetic and Biogeographic Analyses

“…These events have 100% bootstrap support in the maximum likelihood tree (see File S1). This topology suggests that the Russian isolates represent a recent introduction into Russia from Canada, as has been previously suggested (36).…”

“…Based on the close relationship between the Russian POWV isolates, the original Canadian isolate, and the single Russian lineage in the tree, the most parsimonious explanation is a single introduction of POWV into Russia. Previous papers have speculated that importing American mink into Russia was responsible for this introduction (36). Given the Russian presence in Alaska until 1867, it is likely this introduction occurred during this time.…”

“…Lineage II has been named deer-tick virus (DTV) and shows distinct geographical clustering in New England and the midwest (42). POWV has also been isolated in the Primorsky region of Russia; the high level of similarity between Russian and North American isolates and their limited genetic variability resulted in estimates that POWV was introduced into Russia from North America during the past 100 years (36).…”

Molecular evolution of the tick-borne encephalitis and Powassan viruses

“…Another study assessed the nucleotide substi tution rate in the sequence encoding the surface glyco protein E as [1.0-4.5] × 10 -5 [24]. We used the obtained value of the nucleotide substitution rate to evaluate the age of the nearest common ancestor of the two major PV clusters; it was determined to be 2030 years (Fig.…”

The diversity and prevalence of hard ticks attacking human hosts in Eastern Siberia (Russian Federation) with first description of invasion of non-endemic tick species

“…Finally, there are several bird species that perform annual migrations between Asia and North America, including the bar-tailed godwit (Limosa lapponica), the sandhill crane (Grus canadensis), the yellow wagtail (Motacilla flava), the arctic warbler (Phylloscopus borealis) and, most interestingly, a grey-cheeked thrush (Catharus minimus) that has been found to be responsible for the spread of A. americanum in Canada (Scott et al 2001;Gill et al 2009;Krechmer et al 1978;Ehrlich et al 1988;Alström et al 2011). The high possibility of regular tick migration between North America and Asia and associated pathogen transfer is also supported by recent findings of North American Powassan virus in ecosystems of Russian Far East (Leonova et al 2009;Deardorff et al 2013).…”