Crimean-Congo hemorrhagic fever

A viral disease characterized by hemorrhage (bleeding) and fever. Crimean-Congo hemorrhagic fever (CCHF) is a severe disease with a high mortality (death) rate. The geographical distribution of the virus, like that of the tick that carries it, is widespread. CCHF has been found in Africa, Asia, the Middle East and Eastern Europe. The CCHF virus infects a wide range of domestic and wild animals that serve as reservoirs for the virus. Ticks carry the virus from animal to animal and from animal to human. The most important source for acquisition of the virus by ticks is infected small vertebrate animals on which the ticks feed. Once infected, the tick remains infected through its lifespan. The mature tick transmits the infection to large vertebrates such as livestock (cattle, sheep and goats). Humans acquire the virus from direct contact with their blood or other infected tissues from livestock during this time, or they may become infected from a tick bite. The majority of cases of CCHF have occurred in those involved with the livestock industry, such as agricultural workers, slaughterhouse workers and veterinarians. The onset of symptoms from CCHF is sudden with fever, myalgia (aching muscles), dizziness, neck pain and stiffness, backache, headache, sore eyes and photophobia (sensitivity to light). There may be nausea, vomiting and sore throat early on, accompanied by diarrhoea and abdominal pain. Over the next few days, the patient may experience sharp mood swings and become confused and aggressive. The agitation may be replaced by sleepiness, depression and lassitude, and the abdominal pain may localize to the right upper quadrant (over top of the liver) with detectable liver enlargement. Other signs may include tachycardia (fast heart rate), lymphadenopathy (enlarged lymph nodes), and a petechial rash (a rash caused by bleeding into the skin), both on internal mucosal surfaces, such as in the mouth and throat, and on the skin. The petechiae (bleeding spots) may give way to ecchymoses (bruises, like a petechial rash, but covering larger areas) and other hemorrhagic (bleeding) phenomena such as melena (bleeding from the upper bowel, passed as altered blood in the feces), hematuria (blood in the urine), epistaxis (nosebleeds) and bleeding from the gums. There is usually evidence of hepatitis. The severely ill may develop hepatorenal (liver and kidney) failure and pulmonary (lung) failure. The mortality (death) rate from CCHF is about 30% with death, when it occurs, usually coming in the second week of the illness. In those patients who recover, improvement generally begins on the ninth or tenth day after the onset of illness. Diagnosis of CCHF is performed in specially-equipped biosafety laboratories by what is called enzyme-linked immunoassay (ELISA). Patients with fatal disease do not usually develop a positive ELISA test and in these individuals, as well as in patients in the first few days of illness, diagnosis is achieved by virus detection in blood or tissue samples.

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a hemorrhagic fever caused by the Crimean-Congo hemorrhagic fever virus, transmitted by ticks, especially those of the genus Hyalomma, and by contact with blood, secretions, or fluids from infected humans or domestic animals; it occurs in southern Russia, Central Asia, and sub-Saharan Africa.