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Monkey to Man Transmission of Plasmodium falciparum by Anopheles freeborni Mosquitoes

1968; American Society of Parasitologists; Volume: 54; Issue: 6 Linguagem: Inglês

10.2307/3276985

1937-2345

William E. Collins, Peter G. Contacos, Elizabeth G. Guinn, Marvin H. Jeter, Thomas M. Sodeman,

Mosquito-borne diseases and control

Infections of Plasmodium falciparum (Malayan IV strain) in the Aotus trivirgatus monkey were shown to be infectious to Anopheles freeborni mosquitoes. Sporozoite positive salivary glands were found 12 to 19 days after feeding. Transmission of the infection to two men was obtained by the bites of infected mosquitoes after extrinsic incubation periods of 14 to 17 days. The prepatent periods in the men were 11 and 12 days. The successful infection of New World monkeys with human malaria was first reported with Plasmodium falciparum in the howler monkey, Alouatta villosa, by Taliaferro and Taliaferro (1934) and Taliaferro and Cannon (1934). More recently, night monkeys, Aotus trivirgatus, titi marmosets, Saguinus geoffroyi, and the squirrel monkey, Saimiri sciureus, have been infected with P. vivax (Young et al. 1966; Porter and Young, 1966; and Deane, et al. 1966). In addition, Aotus trivirgatus monkeys and S. geoffroyi marmosets have been infected with P. falciparum (Geiman and Meagher, 1967; Porter and Young, 1967). Anopheles albimanus mosquitoes infected with P. vivax by feeding on an Aotus trivirgatus monkey transmitted the infection by bite to two human volunteers (Young et al. 1966) and Anopheles freeborni mosquitoes infected with P. falciparum by feeding on this species of monkey transmitted the infection by bite to one human volunteer (Contacos and Collins, 1968). These successful efforts to infect New World monkeys with the human malarias have made it possible to use these hosts for the study of the human malaria parasites. Reported here are the results of mosquito infectivity studies with Aotus trivirgatus monkeys infected with P. falciparum using Anopheles freeborni mosquitoes. MATERIALS AND METHODS The strain of P. falciparum was the Malayan IV which was isolated from a Peace Corps volunteer who contracted the infection while working in the Central Perak area of Peninsular Malaysia (Chin et al. 1966). The parasite is resistant to chloroquine, chlorguanide, pyrimethamine, and mepacrine but yields to 5 days of quinine sulfate at 30 grains per day. Received for publication 2 August 1968. The An. freeborni mosquitoes were the F-l strain originally isolated from Marysville, California and maintained in the laboratory since then (Hardman, 1947). During the infection, thick and thin blood films were made, stained with Giemsa and parasite counts recorded per 100 WBC. Aotus trivirgatus monkeys were obtained commercially. Prior examination indicated that they were free of natural malarial infection. For monkey feeding, mosquitoes were caged in pint ice cream cartons, both ends of which were covered with nylon bobinet. The monkeys were bound to a board, the center of which had been cut out so that when suspended by the four corners, the shaved belly of the monkey could be rested on the top of the mosquito cage. Mosquitoes fed directly through the netting and after feeding were transferred to a constant temperature incubator and held at 25 C. Cellulose pledgets soaked with 5% Karo solution were applied daily. Dissections were started on the 5th day after feeding. For the transmission attempts, mosquitoes were transferred to small plastic tubes and fed individually on a human volunteer. After feeding, mosquitoes were dissected and the salivary glands examined for presence of sporozoites.