Molecular variability and genetic structure of Omsk hemorrhagic fever virus, based on analysis of the complete genome sequences.

Omsk hemorrhagic fever virus (OHFV) is the etiological agent of Omsk hemorrhagic fever, a disease described in the 1940s in Western Siberia. However, until now, it has been represented in GenBank by just four complete genome sequences, which do not reflect the real genetic diversity of the virus in nature. In this study, we analyzed the molecular variability and genetic structure of OHFV based on 20 complete genome sequences, fifteen of which were obtained for the first time. All these sequences belong to virus strains isolated at different times from three regions of Western Siberia. The results suggest that the genetic diversity of OHFV is significantly wider than previously thought and is represented by at least three subtypes, rather than two. This broadens our understanding of the evolutionary history of OHFV. Also, it is argued that the OHFV reference strain Bogoluvovska (NC_005062) is actually a Kubrin strain and that either cross-contamination or a laboratory error was the cause of this.