Infections of the SV-I strain of Plasmodium vivax from Vietnam were transmitted via the bites of infected Anopheles stephensi, An. maculatus, and An. balabacensis balabacensis mosquitoes. Infected salivary glands were also found in An. freeborni mosquitoes. In 18 successful transmissions, prepatent periods ranged from 10–17 days. Four black volunteers failed to develop infections even though they were fed upon by heavily infected An. maculatus and An. b. balabacensis mosquitoes.
Present address: Vector Biology and Control Division, Bureau of Tropical Diseases, Center for Disease Control, Atlanta, Georgia 30333.