Abstract
INTRODUCTION: Crimean-Congo hemorrhagic fever (CCHF) is one of the most acute tick-transmitted zoonotic diseases. The purpose of this study was to determine the molecular characteristics and phylogenetic analysis of the CCHF virus based on the S-segment nucleocapsid gene in Ardabil Province, northwestern Iran. MATERIALS AND METHODS: From November 2021 to May 2023, a total of 20 peripheral blood specimens were collected from suspected CCHF patients. Following RNA extraction, the partial nucleotide sequence of the S fragment was amplified (536 bp) using a one-step RT-PCR Kit. PCR products were successfully sequenced to perform phylogenetic analysis and haplotype distribution. RESULTS: The mean age of CCHF patients was 30.4 ± 10.45 years and all male patients had a history of tick exposure. According to molecular findings, the frequency of CCHFV in patients was 25% (5/20). A high haplotype diversity (Hd: 1; haplotype number: 5) and distinct genetic clade (IV) of CCHFV were identified among the patients in Ardabil province compared to other regions of Iran. CONCLUSION: The occurrence of new haplotypes shows new evidence of the emerging threat of the CCHFV in the region. Current findings strengthen our knowledge of transmission dynamics and dispersion of probable drug-resistant alleles of CCHFV in northwestern Iran, also it will become the basis of public health policy to control CCHF in the region. CLINICAL TRIAL NUMBER: Not applicable.