edited by W. H. Taliaferro, Division of Biological and Medical Research, Argonne National Laboratory, Argonne, Illinois, and J. H. Humphrey, National Institute of Medical Research, London, England. Vol. 1, x + 423 pages, illustrated. New York, London, Academic Press. 1961. $12.00
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
Department of Epidemiology, Applied Research Division, U.S. Army Medical Research Institute of Infectious Diseases, Tropical and Geographical Disease Institute, Department of Biological Sciences, Ohio University, Fort Detrick, Frederick, Maryland
The ability of adult Anopheles stephensi to transmit Rift Valley fever virus was determined for mosquitoes inoculated at selected times during development. None of 109 female An. stephensi inoculated as adults transmitted virus to hamsters. In contrast, 83% (50 of 60) of those inoculated as larvae transmitted virus by bite to hamsters. Transmission rates decreased as the stage of the mosquito at the time of inoculation changed from larva to pupa to adult. Transmission rates for adult mosquitoes inoculated as larvae, as pupae < 4 hr after pupation, as pupae > 24 hr after pupation, or as adults were 83%, 25%, 11%, and 0%, respectively. Viral titers recovered from mosquitoes were similar for all groups tested, regardless of stage at infection (larva, pupa, or adult) or of transmission status (transmitter or nontransmitter). Thus, differences in transmission rates may have been due to site-specific (i.e., salivary gland) replication, rather than a generalized increase in viral replication in mosquitoes inoculated at an earlier age.