Crimean-Congo hemorrhagic fever(redirected from African tick fever)
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Crimean-Congo hemorrhagic fever,acute, sometimes fatal disease endemic in many parts of Eurasia and Africa, caused by a tick-borne virus. The virus, an RNA virus (Nairovirus) of the Bunyaviridae family, is typically transmitted to humans by ticks of the genus Hyalomma, although humans are not their preferred hosts. It usually incubates for one to six days (though it can be up to 13 days) before an infected person suddenly develops such symptoms as high fever, headache, neck, back, muscle, joint, or abdominal pain, dizziness, vomiting and diarrhea, sensitivity to light, petechiae (red spots caused by bleeding in the skin) in mouth and throat, jaundice, and in severe cases mood changes and confusion sometimes followed by exhaustion and sleepiness. After several days, large areas of bleeding under the skin resembling bruises as well as uncontrolled nosebleeds and other bleeding may develop; in severe cases kidney deterioration or liver or pulmonary failure may follow. There is no cure or vaccine for the disease; patient treatment involves managing the symptoms and treating any secondary infection. The antiviral drug ribavirin may provide some benefit, but its efficacy has not been confirmed. Death occurs in 10% to 40% of the cases; survivors recover slowly.
The virus is most commonly contracted by herders and other agricultural workers from adult ticks on infected domestic livestock; the virus, however, generally does not cause disease in livestock and other animals, such as hares, hedgehogs, and other small wild mammals that host the immature ticks. Infections also commonly occur among slaughterhouse workers and among medical personnel and others who are in close contact with the blood and other bodily fluids of an infected individual.
The disease was first identified in Crimea in 1944 and called Crimean hemorrhagic fever. In the 1950s and 60s a virus was isolated in the Belgian Congo and subsequently described; the then-named Congo virus was later determined to be identical to a virus isolated (1967) from a Central Asian patient with Crimean hemorrhagic fever. The disease was given its current official name in 1973.