Venezuelan hemorrhagic fever, a hemorrhagic fever caused by an arenavirus transmitted to humans by contact with or inhalation of aerosolized excreta of infected rodents. The disease occurs in west central Venezuela, primarily in settlers moving into areas of cleared forest. Initially it is characterized by the gradual onset of fever, malaise, myalgia, and anorexia, followed by prostration, dizziness, headache, back pain, and GI disturbances. Bleeding of the gums is a typical finding, and there may be petechiae on the palate and axillae. Neurological manifestations, such as tremor of tongue and hands, diminished deep tendon reflexes, lethargy, and hyperesthesia, often occur. Most patients begin to improve after 1 or 2 weeks, but the disease takes a more serious course in about a third; some patients develop a hemorrhagic diathesis; some develop severe neurological deterioration marked by delirium, coma, and convulsions; and still others develop a mixed hemorrhagic-neurologic syndrome with shock. Treatment is supportive, with careful attention to fluid and electrolyte balance. If untreated, the case fatality rate may reach 30% or more. With aggressive treatment, the usual prognosis is complete recovery.