V. Evaluation of Cross-Immunity against Type 1 Dengue Fever in Human Subjects Convalescent from Subclinical Natural Japanese Encephalitis Virus Infection and Vaccinated with 17D Strain Yellow Fever Vaccine
A virus strain (AR 2204) was isolated from a pool of 19 Mansonia (Mansonioides) uniformis (Theobald); another virus strain (AR 2211) was isolated from a pool of 278 Aedes (Neomelaniconion) circumluteolus (Theobald).
Serological studies utilizing CF and NT techniques have shown the two virus strains to be immunologically indistinguishable. Similar studies including also the HI technique indicate that the virus is not related to a wide spectrum of other arthropod-borne viruses. The agent has been named Ndumu virus after the locality where the mosquitoes were collected.
Ndumu virus is sensitive to the action of sodium desoxycholate. A vervet monkey was inoculated with Ndumu virus and the agent was detected in the serum on the 8th and 10th postinoculation days. Protection test surveys indicate that Ndumu virus has been active among human beings residing in widely scattered areas in southern Africa.
Present address: The Rockefeller Foundation, 111 West 50th Street, New York 20, New York.