Detection of new Crimean-Congo haemorrhagic fever virus genotypes in ticks feeding on deer and wild boar, Spain.

Abstract

Crimean-Congo haemorrhagic fever virus (CCHFV) is the causative agent of the severe tick-borne, often fatal, zoonotic Crimean-Congo haemorrhagic fever (CCHF), 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. Given the emergence of CCHF and the role of ticks in pathogen maintenance and transmission, we investigated the presence and genotype identity of the virus in tick species parasitizing abundant wild host species in south-western Spain. A total of 613 adult ticks were collected from hunter-harvested wild ungulates in twenty locations throughout south-western Spain. Ticks were identified, nucleic acids were extracted, RNA was analysed by a nested RT-PCR targeting CCHFV S segment, and the amplicons were sequenced. According to the 212-bp sequence amplified, the presence of CCHFV human genotype Europe V was detected in Hyalomma lusitanicum and Dermacentor marginatus ticks collected from red deer, fallow deer and Eurasian wild boar in different locations from south-western Spain. Genotype Africa IV was also detected in a H. lusitanicum tick collected from a red deer. The detection of CCHFV in different tick species collected from various wild hosts and localities provided strong evidence of widespread CCHFV presence in the region, suggesting that the circulation of the virus 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.