Crimean–Congo Hemorrhagic Fever Virus Clade IV (Asia 1) in Ticks of Western Iran

Crimean–Congo Hemorrhagic Fever virus (CCHFV) is transmitted through the bite of an infected tick, or by direct contact with CCHFV-infected patients' blood or the products of infected livestock. In 2012, ticks were collected in eight regions of Lorestan Province, Iran. In total, 434 ticks were collected. Reverse transcriptase polymerase chain reaction was used for the detection of CCHFV RNA. Of 434 ticks, 419 (96.6%) ticks were from the family Ixodidae (hard ticks) and 15 (3.5%) ticks were from the family Argasidae (soft ticks). The presence of CCHFV RNA was detected in 29 (6.7%) of 434 ticks. The infected tick species include Hyalomma asiaticum (n = 7, 7.4%), Hyalomma anatolicum (n = 12, 13.2%), Hyalomma marginatum (n = 1, 16.7%), and Rhipicephalus sanguineus (n = 9, 4.3%). These empirical data demonstrated that the majority of CCHFV-positive ticks belonged to the Ixodidae. None of the Argasidae and Haemaphysalis sulcata species was infected with CCHFV. The phylogenetic analyses of the tick-derived CCHFV strains revealed that all 29 viral strains fell in clade IV (Asia 1). The most abundant species of tick collected in this study was R. sanguineus followed by different species of Hyalomma. Given the infection rate among collected ticks, H. marginatum was the most abundant infected tick species (16.7%) followed by H. anatolicum (13.2%), H. asiaticum (7.4%), and R. sanguineus (4.3%).