Studies on the Transmission of Simian Malaria V. Infection and Transmission of the B Strain of Plasmodium cynomolgi

Five species of mosquitoes, Anopheles freeborni, A. balabacensis balabacensis, A. maculatus, A. stephensi, and A. quadrimaculatus, were examined with regard to their susceptibility to infection with the B strain of Plasmodium cynomolgi. It was found that feedings between the 9th and the 16th days of patent parasitemia in intact Macaca mulatta monkeys resulted in the heaviest mosquito infection. Oocyst counts of greater than 20 per gut resulted in heavy salivary gland infections in 50% or more of the test mosquitoes. Transmission to M. mulatta monkeys was obtained in 95 of 103 attempts by the bites of from 2 to 250 mosquitoes. The prepatent period ranged from 7 to 18 days with a median of 11 days.