[Crimean-Congo hemorrhagic fever: basics for general practitioners]

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease described in more than 30 countries in Europe, Asia and Africa. The causative agent is the Crimean-Congo hemorrhagic fever virus (CCHFV) that is a member of the genus Nairovirus of the family Bunyaviridae. CCHFV that is characterized by a high genetic variability is transmitted to humans by tick bites or contact with fluids from an infected individual or animal. The initial symptoms of CCHF are nonspecific and gradually progress to a hemorrhagic phase that can be lethal (case-fatality rate: 10 to 50%). Characteristic laboratory findings of CCHF are thrombocytopenia, elevated liver and muscle enzymes, and coagulation defects. The pathogenesis of CCHF remains unclear but might involve excessive pro-inflammatory cytokine production and dysfunction of the innate immune response. Diagnosis of CCHF is based mainly on isolation of the virus, identification of the viral genome by molecular techniques (RT-PCR), and serological detection of anti-CCHFV antibodies. There is currently no specific treatment for CCHFV infection and the efficacy of ribavirin is controversial. In absence of an effective vaccine, prevention is based mainly on vector control, protection measures, and information to increase the awareness of the population and of healthcare workers.