spatial and phylodynamic survey on crimean-congo hemorrhagic fever virus strains in northeast of iran

Background: crimean-congo hemorrhagic fever (cchf) is asymptomatic in infected animals, yet the virus poses a serious threat to humans causing a symptomatic, hemorrhagic disease with a high case-fatality rate. numerous genera of ticks serve as both vectors and reservoirs of the crimean-congo hemorrhagic fever virus (cchfv). objectives: the aim of the present study is to determine the cchfv prevalence in ticks from northeast iran to establish a phyloge- netic relationship of the tick-derived cchfv strains circulating in iran. methods: during april to june 2015, a total of 93 hard ticks were collected from different animals in the damghan district. the s- segment of positive samples was fully sequenced using the sanger technique. a total of 142 cchfv sequences comprised full-length of cchfv sequences obtained in this study were aligned using the mafft algorithm, then phylogenetic tree was constructed using geneious v 7.1.8. results: the identified tick species included hyalomma marginatum (6.5%), hy. dromedarii (21.5%), hy. anatolicum (15.1%), hy. asiaticum (3.2%) and hy. schulzei (2.2%), as well as rhipicephalus sanguineus (47.3%). the cchfv rna was detected in 4 samples of 93 tick samples (4.3%) by rt-pcr. a total of 4 cchfv sequences were obtained in this study clustered within clade iv (asia-1 and asia-2). conclusions: we demonstrated that 4 species of hard ticks could be a vector for cchfv in iran. in addition, our findings indicate the circulation of cchfv clade iv strain in the northeast of iran and provide a solid base for more targeted surveillance and prevention programs in iran.