Crimean-Congo haemorrhagic fever.

Crimean-Congo haemorrhagic fever (CCHF) is one of the most widespread arboviroses in the world. It is present in Africa, south-east Europe, the Middle East and Asia. It is caused by a nairovirus (Bunyaviridae family) transmitted by several species of ticks. The geographical distribution of the disease coincides with the distribution of Hyalomma ticks. While infected livestock do not show signs of illness, humans are severely affected, with a high mortality rate. The most common symptoms are high fever, dizziness, headache, vomiting and haemorrhages. Pathogenesis studies in interferon-receptor-deficient mice indicated that the interferon response is crucial in controlling virus propagation and in protecting against the disease. Detection of the virus in biological material is currently performed by reverse-transcription polymerase chain reaction. Enzyme-linked immunosorbent assay and indirect immunofluorescence are used to detect the presence of CCHF virus-specific antibodies. In the 1970s, a formalin-inactivated vaccine prepared from suckling mouse brain was used in Eastern Europe and the former Soviet Union, but its efficacy remains to be proven. Treatment of patients with ribavirin is recommended by the World Health Organization, but it should be administered as early as possible. Although important progress has been made over the last few decades, many questions about the pathogenesis and epidemiology of the disease are still to be addressed and there is a need to develop efficient vaccines and antivirals.