RÉSUMÉ
Background & objectives: Crimean-Congo Hemorrhagic Fever (CCHF) is a deadly viral infection reported from more than 30 countries. It is considered a zoonosis? and tick bites are the main route of transmission in nature. So far, the virus has been identified in 31 species of hard (Ixodidae) and soft (Argasidae) ticks. The aim of this study was to determine the rate of CCHF virus infection in hard ticks from South-Khorasan province, east of Iran. Methods: In this study, 684 livestock including 302 sheep, 344 goats, 16 cows and 22 camels were sampled from Birjand, Qaen, Khusf, Darmian and Sarbisheh counties. Genus and species of the ticks were diagnosed under stereomicroscope according to valid morphological keys. Reverse transcription-polymerase chain reaction (RT-PCR) method was used to detect the CCHF virus genome based on S segment in 100 ticks. Results: RT-PCR detected CCHF virus genome in 7 out of 100 ticks. Positive ticks belonged to Hyalomma and Rhipicephalus genera. CCHF virus infected species were Rhipicephalus sanguineus, Hyalomma detritium and Hyalomma asiaticum. All the infected ticks were isolated from goat and sheep and were from Birjand county. Interpretation & conclusion: Our results suggest that Hyalomma and Rhipicephalus may be the main vectors of CCHF virus in the study area.