Clinical, Clinicopathologic, and Hematologic Features of Kyasanur Forest Disease

In 1957, a fatal disease occurred among monkeys in a forested area of Shimoga District, Karnataka State, India. Concurrently, there was an outbreak of febrile, occasionally fatal illness among people living in the vicinity. The disease was caused by a new tick-borne flavivirus belonging to the Russian spring-summer encephalitis complex of viruses. The early clinical description of the disease included severe cases with hemorrhagic manifestations, including intermittent epistaxis, hematemesis, melena, and frank blood in the stools. Pathologic and hematologic investigations emphasized similarities with Omsk hemorrhagic fever. Two years later there was a shift in clinical emphasis from hemorrhagic to neurologic complications; this could have resulted from the special interests or bias of the principal investigator or the changing patterns of intercurrent infections. Clinical, clinicopathologic, hematologic, and hemostatic features of Kyasanur Forest disease (KFD) are described, particularly in relation to IgE as a cofactor in the immunopathology of KFD and possibly of other hemorrhagic fevers. In 1957 there were reports of a fatal epizootic in monkeys in the forested areas of Shimoga District, Karnataka State, India. Concurrently, a disease occurred in humans that was thought to be enteric fever by local practitioners and public health authorities. The villagers called the affliction "monkey disease" because of the known association with dead monkeys. This association was confirmed when identical strains of virus were isolated from organs of dead monkeys and from the acute-phase sera of patients [1]. Since that time the virus has been isolated from many other