Molecular Confirmation and Sequencing of Crimean-Congo Hemorrhagic Fever Virus in Ticks in Armenia (2022–2024)

Abstract

Crimean-Congo hemorrhagic fever (CCHF) is an emerging tick-borne disease with a growing global distribution. In Armenia, 31 Ixodidae tick species have been identified, including Hyalomma species. While CCHF virus (CCHFV) was previously isolated from ticks in the 1970s, no further studies were conducted until 2016, when antibody to CCHFV was identified.

This study aimed to update data on the Ixodidae tick species, detect CCHFV in collected specimens, and perform molecular characterization of viral lineages circulating in Armenia during 2022–2024.

Epizootiological investigations were performed across all 10 regions of Armenia. Fieldwork involved the collection of Ixodidae ticks, followed by morphological identification and testing of specimens. A total of 550 animals (including cattle, sheep, and horses) and surrounding open habitats were surveyed, resulting in the collection of 3158 Ixodidae ticks representing 12 species. These samples were organized into 960 pools and tested via reverse transcriptase polymerase chain reaction for CCHFV. Viral RNA was detected in 96 pools, all originating from ticks collected from cattle and representing 8 species. Positive samples were confined to two regions: Syunik and Tavush. Phylogenetic analysis revealed the presence of two CCHFV lineages in Armenia: Europe 1 (Subgroup V) and Europe 3 (Subgroup VII).

Armenia’s climatic and geographic diversity, expanding land use, population mobility, and growing tourism highlight the need for continued surveillance. The present identification of CCHFV in ticks in two regions emphasizes the importance of ongoing epizootiological monitoring and molecular characterization to assess the broader epidemic risk across the country.