Detection of New Crimean-Congo Hemorrhagic Fever Virus Genotypes in Ticks Feeding on Deer and Wild Boar, Spain

Abstract

Background: Crimean-Congo hemorrhagic fever virus (CCHFV) is the causative agent of the severe tick-borne, which is widely distributed worldwide. The CCHFV transmission to humans occurs through tick bite, crushing of engorged ticks, or contact with infected host blood. Previously, CCHFV genotype Africa III was reported in Spain. Methods: A total of 613 ticks, including Hyalomma lusitanicum and Dermacentor marginatus, were collected from hunter-harvested wild ungulates in twenty locations throughout southwestern Spain. Tick RNA was analyzed by a nested RT-PCR targeting CCHFV S segment and the amplicons were sequenced. Findings: The study reports the presence of CCHFV human genotype Europe V in both tick species collected from red deer (Cervus elaphus), fallow deer (Dama dama), and Eurasian wild boar (Sus scrofa). Viral RNA was detected in 129 of the analyzed ticks. Most of the CCHFV S segment sequences showed 99-100% identity to reported sequences of human isolates from Russia and Iran belonging to genotype Europe V. Interpretation: The detection of CCHFV in different tick species collected from various wild host species and localities provided strong evidence of widespread CCHFV presence in the region, suggesting that CCHFV circulation in Spain requires more attention. Additionally, the identification of the CCHFV genotype Europe V in ticks suggested that its introduction in Spain was probably from Eastern Europe. Funding: This study was partially supported by MINECO Plan Nacional grant CGL2017-89866-R and EU-FEDER. Declaration of Interest: The authors declare no commercial or financial conflict of interest. Ethical Approval: Tick sampling were collected according to hunting disease surveillance schemes and in the framework of Spanish and EU laws for notifiable disease surveillance. Therefore, no Animal Ethics Committee approval was required for the collection of ticks from hunter harvested wild ungulates.