Bwamba Fever and Its Causative Virus

Abstract

Summary A clinical entity, Bwamba fever, believed to be hitherto unknown, is described. The disease is characterized by rather sudden onset, fever, headache and backache. Symptoms persist for about 5 to 7 days and subside without sequelae. Fatal cases of the disease have not been seen. Nine strains of filterable virus were isolated from the blood of as many patients suffering from this illness. The original sera of these 9 patients failed to neutralize the virus, whereas convalescent sera of all the patients contained neutralizing antibody against the virus. Further immunological and biological tests indicate that the 9 strains of virus are related or identical. The agent is pathogenic for, and causes death of, mice by intracerebral or intranasal inoculation. It causes non-fatal febrile illness when given intracerebrally to rhesus monkeys. Guinea pigs and rabbits are not susceptible to the virus. Monkeys and guinea pigs which survive inoculation with the virus develop neutralizing antibody. The virus is filterable through Berkefeld filters of all grades (through the finer grades with some difficulty) and through Seitz EK pads. Experiments with filtration through gradocol membranes indicate that the size of the virus approximates 113 to 150 mµ. Lesions caused by the virus in mice are essentially limited to the nervous system and are characterized by damage to cortical cells in various areas of the brain, and by the appearance of intranuclear acidophilic bodies resembling inclusions. Certain other properties of the virus are described.