en Health Health Original Research Original Research <strong>Background: </strong>Crimean-Congo hemorrhagic fever (CCHF) is a prevalent tick-borne disease in different regions of Iran. This molecular and serologic study was performed to investigate the Crimean-Congo hemorrhagic fever virus (CCHFV) in collected ticks and in blood samples of some domestic animals in North Khorasan, Northeast of Iran.<br> &nbsp;&nbsp; <strong>Methods:</strong> In this cross sectional study, 136 blood samples from domestic animals (sheep, goats, and cows) collected in the Northeast region in Iran were examined using IgG ELISA assay. Ticks (n&thinsp;=&thinsp;1478) were collected from sheep, goats, and cows. Out of all collected ticks, 62 specimens were investigated for CCHF virus genome using RT-PCR technique. The data were descriptively presented by median and 95% confidence interval (CI).<br> &nbsp;&nbsp; <strong>Results:</strong> CCHFV infection rate was 8.1% in studied ticks. Two species of ticks, Hy. anatolicum (n=3; 15%, 95% CI 9.41&ndash;20.59) and Rh. sanguineus (n=2; 6.9%, 95%CI 4.33&ndash;8.58), were infected with CCHFV genome and were probable vectors of CCHF virus in the area. Infection rate was 15.4% for CCHFV in tested domestic animals. Serologic tests detected CCHFV specific IgG antibodies in 16.2% (95% CI 13.49&ndash;18.83) (99/16) and 19.2% (95% CI 13.26&ndash;25.20) (26/5) of sheep and goats, respectively.<br> &nbsp;&nbsp; <strong>Conclusion:</strong> The present study showed that domestic animals and ticks were infected with Crimean-Congo hemorrhagic fever virus and that the disease was endemic in North Khorasan province, Iran. However, further surveillance and prevention programs are recommended. Crimean-Congo hemorrhagic fever, Ticks, Molecular technique, Serological test, Iran 249 254 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-3747-1&slc_lang=en&sid=1 Abedin Saghafipour abed.saghafi@yahoo.com 200319475328460062708 200319475328460062708 No Department of Public Health, Faculty of Health, Qom University of Medical Sciences, Qom, Iran Ahmad Mousazadeh-Mojarrad Amojarrad@yahoo.com 200319475328460062709 200319475328460062709 No Vector-borne Diseases Research Center, North Khorasan University of Medical Sciences, Bojnurd, Iran Niloofar Arzamani niloofar.arzamani@gmail.com 200319475328460062710 200319475328460062710 No School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Zakyeh Telmadarraiy telmadarraiy@tums.ac.ir 200319475328460062711 200319475328460062711 No Department of Medical Entomology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Rezvan Rajabzadeh rajabzade.61@gmail.com 200319475328460062712 200319475328460062712 No Department of Epidemiology, Student Research Committee, Iran University of Medical Sciences, Tehran, & Vector-borne Diseases Research Center, North Khorasan University of Medical Sciences, Bojnurd, Iran Kourosh Arzamani Arzamanik@gmail.com 200319475328460062713 200319475328460062713 Yes Vector-borne Diseases Research Center, North Khorasan University of Medical Sciences, Bojnurd, Iran