Genetic evidence of regional circulation of Crimean-Congo hemorrhagic fever virus in ixodid ticks from southern Kazakhstan.

Abstract

INTRODUCTION: Arthropod-borne viruses (arboviruses) pose a growing threat to livestock and human health across Central Asia. This study aimed to assess the presence and genetic diversity of arboviral pathogens-Crimean-Congo hemorrhagic fever virus (CCHFV), Bluetongue virus (BTV), Schmallenberg virus (SBV), and lumpy skin disease virus (LSDV)-in ixodid ticks livestock in southern Kazakhstan. METHODS: A total of 3,281 adult ticks were collected from three regions (Turkestan, Zhambyl, and Kyzylorda) and identified morphologically. Molecular screening was performed using real-time and nested RT-PCR. RESULTS: CCHFV RNA was detected exclusively in female ticks from the Turkestan region, with Dermacentor pictus showing the highest infection rate (21.05%), followed by Hyalomma anatolicum, Dermacentor marginatus, and Hyalomma scupense. No viral RNA was detected for BTV, SBV, or LSDV. DISCUSSION: Phylogenetic analysis based on partial S and L segments revealed that the Kazakhstani isolates clustered within Asia-1 and Asia-2 genotypes and shared high sequence identity with regional strains from Uzbekistan, Turkmenistan, and China, supporting transboundary virus circulation. These findings provide additional molecular evidence of localized CCHFV activity in livestock-associated ticks in southern Kazakhstan, expanding current knowledge on the virus's geographic distribution and genetic diversity.