Detection of the Crimean-Congo Hemorrhagic Fever Virus Genome in Questing Ixodes spp. and Haemaphysalis spp. in the Periurban Forestry Areas of Istanbul: Has a New Biorisk Emerged?

Vector Borne Zoonotic Dis. 2023 Oct;23(10):528-536. doi: 10.1089/vbz.2023.0023. Epub 2023 Aug 1.

Abstract

Background: Istanbul is one of the world's most densely populated metropolitan cities, with various geographical areas that possess distinct characteristics. These areas have different climates, vegetation, and host populations that can support the survival of diverse tick species. Turkey is a region with a high risk of Crimean-Congo hemorrhagic fever (CCHF) disease, making it crucial to screen for this risk, especially in densely populated regions such as Istanbul and its surrounding areas. However, the presence of potential vectors for CCHF virus (CCHFV) in these areas has not been studied in the past 12 years. Materials and Methods: In this study, a total of 676 ticks were collected from 6 centers using the flagging and dragging method. Ticks were identified as Ixodes ricinus (7.85%), Ixodes spp. immature form (73.22%), Haemaphysalis parva (0.89%), Haemaphysalis inermis (0.15%), and Haemaphysalis spp. immature form (17.89%). Pooled samples were screened for the CCHFV genome (S segment) by RT-nested PCR. Results: A total of 14.28% of the samples were found as positive. Phylogenetic analysis revealed that all the CCHFV sequences obtained from the positive samples were clustered in clade V: Europe/Turkey genogroup. Conclusion: This study suggests that ixodes spp. and Haemaphysalis spp. may have the potential to pose a biorisk for Crimean-Congo hemorrhagic fever.

Keywords: CCHF; Haemaphysalis; Istanbul; Ixodes.