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The case-fatality rate of this tickborne viral disease varies from 2% to 50%. Patients have severe limb pain and develop a petechial rash beginning on the trunk. Hemorrhages are prominent in severe cases. Laboratory findings include leukopenia and thrombocytopenia. Hospital workers may become infected after exposure to blood and secretions. Other cases result from workers handling the tissues of infected animals. Ticks, hares, birds, and possibly rodents are the animal reservoirs. Sheep, goats, and cattle are suspected amplifying hosts. [CCDM, p. 52-4] Patients may have flushing of the face and chest, conjunctival injection, and palatal petechiae. The illness may be biphasic with a primary flu-like illness, a few days of remission, and then the secondary hemorrhagic phase. Findings in the second phase may include severe liver injury, bradycardia, pulmonary edema, and epistaxis. Bleeding from IV sites, the nose, and other mucosa is often heavy enough to cause anemia and hypotension. Marked abnormalities of platelet count, transaminase levels, and clotting factors, as well as leukocytosis, predict a fatal outcome. Ribavirin may be of value in treatment. [ID, p. 2144-5] The WHO case definition of acute hemorrhagic fever syndrome includes any 2 of the following: hemorrhagic or purpuric rash, epistaxis, hematemesis, hemoptysis, and blood in the stools. [WHO website] Icteric hepatitis is a common feature of severe disease. [PPID, p. 2088] |