assessment of recombination in the s-segment genome of crimean-congo hemorrhagic fever virus in iran

background: crimean-congo hemorrhagic fever virus (cchfv) belongs to genus nairovirus and family bunyaviridae. the main aim of this study was to investigate the extent of recombination in s-segment genome of cchfv in iran. methods: samples were isolated from iranian patients and those available in genbank, and analyzed by phyloge­netic and bootscan methods. results: through comparison of the phylogenetic trees based on full length sequences and partial fragments in the s-segment genome of cchfv, genetic switch was evident, due to recombination event. moreover, evidence of multi­ple recombination events was detected in query isolates when bootscan analysis was used by simplot software. conclusion: switch of different genomic regions between different strains by recombination could contribute to cchfv diversification and evolution. the occurrence of recombination in cchfv has a critical impact on epidemi­ological investigations and vaccine design.