1.A filterable virus, believed to be hitherto unknown, has been isolated from Aedes mosquitoes caught in uninhabited forest in western Uganda. It has been provisionally named Bunyamwera virus in respect of the locality in which it was encountered.
2.The agent is pathogenic for white mice and exerts its principal pathogenic effects on the nervous system regardless of the route by which it is introduced.
3.The effects of the virus in rhesus monkeys and rabbits are discussed.
4.The agent elicits the formation of virus-neutralizing antibodies in animals which survive inoculation. The presence of these antibodies may be ascertained by intracerebral or intraperitoneal tests.
5.Bunyamwera virus is immunologically different from the viruses of yellow fever, Bwamba fever, St. Louis and Japanese B encephalitis, Rift Valley fever, eastern and western equine encephalomyelitis and horse-sickness, from West Nile and Semliki Forest viruses and from another neurotropic virus isolated here but not yet reported.
6.Neutralizing antibody against the virus has been found in a forest monkey, in a human who suffered a recent attack of febrile illness characterized by marked neurological signs and in a number of persons sampled at random.
Staff Members of the International Health Division, Rockefeller Foundation.
This Institute is supported jointly by the Medical Department of the Uganda Protectorate and the International Health Division of The Rockefeller Foundation.