Genotypic analysis of S segment of Crimean-Congo hemorrhagic fever virus in Turkey.

The Crimean-Congo hemorrhagic fever (CCHF) virus (CCHFV) is a tick-borne virus, whose viral RNA consists of S, L, and M segments. The virus is migrating through the ticks with animals and migratory birds and the geographical distribution can be investigated based on genetic analysis. To better understand the connection between the seropositivity and the mortality rate, the key factor could be the temporal and spatial analysis of the different strains. In this study, serum samples (n = 26) were selected from CCHFV RNA-positive patients and subjected to sequence analysis of the gene regions encoding the S segments. According to the neighbor-joining analysis, the obtained partial sequences were linked to the European strain. The strains were closely related to Turkey-Kelkit06, Turkey 200310849 viruses, and viruses from Russia and Kosovo. The comparison with previously analyzed isolates from the GenBank showed 95%-99% sequence similarity. The isolates in phylogenetic branches were divided into two groups. AST, platelet, and APTT levels were found significantly higher in Group 2 compared to Group 1. Nucleotide differences can be prognostic factor in CCHF disease. Increasing CCHF cases not originating from local isolates were circulating strains imported from different neighboring countries of Turkey. The results show new evidence to the emerging threat of the CCHF disease.