Crimean-Congo hemorrhagic fever, transfer patterns, vectors and history in Iran and neighboring countries

Crimean-Congo hemorrhagic fever (CCHF) is indeed to be considered as one of the most significant vector-borne diseases globally. The virus responsible for CCHF can persist in various animals and lead to severe infections in humans. Ticks of the Ixodidae family are the acknowledged vectors of CCHF virus (CCHFV) transmission to humans. In this review, different tick species from Iran and its neighbors and their roles in the transmission of CCHFV were evaluated. However, the transmission patterns of CCHF to humans primarily involve tick bites, direct contact with the blood, organs, or tissues of contaminated animals, and exposure to CCHF patients are important in virus transmission. The results of this review confirm that the tick vectors in Iran and its neighbors are very common. Even though tick bite is one of the most important risk factors for CCHF, it cannot explain all cases, and there are other important risk factors, such as high-risk occupations and having contact with livestock. Ticks that have been proven to transmit the disease, especially Hyalomma marginatum, are scattered in Iran and neighboring countries. Transporting passengers and livestock and sometimes smuggling livestock are the means of transmitting the virus between neighboring countries. Therefore, there is a need for joint preparedness and response programs to prevent and manage CCHF between Iran and its neighbors.