Studies on the West Pakistan Strain of Plasmodium vivax in Aotus Monkeys and Anopheline Mosquitoes

The West Pakistan strain of Plasmodium vivax was established in 17 Aotus trivirgatus griseimembra monkeys. Parasitemias were moderate. Prior experience of the animals with P. falciparum and a heterologous strain of P. vivax resulted in a marked reduction in parasitemias, but maintenance of mosquito infectivity similar to that of animals with no prior malaria. Comparative infectivity studies indicated that this strain in Aotus monkeys was most infective to Anopheles freeborni mosquitoes followed by An. balabacensis balabacensis, An. maculatus, and An. culicifacies. Anopheles albimanus were infected only rarely. The intensity of the salivary gland infections was highest in An. maculatus followed by An. culicifacies, An. freeborni, and An. b. balabacensis. Transmission via mosquito bite was obtained once with An. freeborni and once with An. maculatus; prepatent periods were 20 and 25 days.