Chapter 7 : Promises, Promises, Promises

Abstract:

The strategic needs for malaria control were self-evident: find suitable primate hosts for the human malarias, discover the means for growing the parasites continuously in vitro, and recruit a cadre of well-trained scientists to direct their studies toward the biochemistry and immunology of malaria parasites in the hope of discovering a protective vaccine. Attempts to induce human malaria infections in nonhuman primates began in 1934 with work in Panama by the Taliaferros, who used the black howler monkey (Alouatta villosa); however, the infections could not be maintained by serial transfer of infected blood. The infection was transmitted by the bite of Anopheles albimanus mosquitoes, using two self-experimentation volunteers (Johnson and Porter), and subsequently their blood infections were used to infect other night owl monkeys. The problem with the use of New World monkeys is their expense and scarcity and the difficulties in handling them in the laboratory. In 1975, USAID advertised for contractors to develop a method for the in vitro cultivation of P. falciparum. In 1969 Trager decided to abandon the Geiman-Harvard rocker dilution method and to substitute a flow vial system in which the culture medium would move gently over a settled layer of infected red blood cells. Although P. falciparum grew well in Trager’s flow vials, the method would not have been practical for growing these parasites outside of laboratories. The greatest value of the candle jar method is that it can be used in laboratories almost anywhere in the world.