Crimean-Congo hemorrhagic fever in Iran and neighboring countries.

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic viral disease that is asymptomatic in infected livestock, but a serious threat to humans. Human infections begin with nonspecific febrile symptoms, but progress to a serious hemorrhagic syndrome with a case fatality rate of 2-50%. Although the causative virus is often transmitted by ticks, livestock-to-human and human-to-human transmissions also occur. The disease is one of the most widely distributed viral hemorrhagic fevers occurring in Africa, the Middle East, Asia, and some parts of Europe. In this study, we have focused on the CCHF situation in Iran and neighboring countries and provide evidence of over 5000 confirmed cases of CCHF in a single period/season.