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We have recently developed a method of in vitro cultivation of P. falciparum using a portable incubator and AnaeroPack.CO2 (Onda et al.), we applied semi-microtechnique drug susceptibility tests to the culture method to evaluate the system using several P. falciparum strains or isolates of different susceptibilities to chloroquine (SGE-1, FCR-3, K-1, Patient 1 and 2). The new method gave comparable results to those shown by the standard test employing a modular incubator chamber with standard gas composition of 5% O2, 5% CO2 and 90% N2. Many useful data on the epidemiology of drug resistant malaria such as the emergence of multi-drug resistant isolates could be collected by applying this new method to the field survey.

AnaeroPack Malaria Culture System (SUGIYAMA-GEN Co., Ltd.) using AnaeroPack.plas (5% O2, 5% CO2) and AnaeroPack.CO2 (15% O2, 6% CO2) was evaluated by comparing with the standard laboratory in vitro continuous culture technique. Two culture-adapted strains of Plasmodium falciparum, SGE-1 (chloroquine sensitive strain) and K1 (chloroquine resistant strain), were continuously cultured for 26 days in vitro under the 3 systems. The parasite proliferation curves under the different set systems were paralleled in both strains, which demonstrate that this AnaeroPack Malaria Culture System is useful for the culture-adapted strains of P. falciparum. Although further test using isolates from falciparum malaria patients should be carried out, the AnaeroPack Malaria Culture System seems promising for the culture in the field studies.

The development of vaccines against malaria, particularly the one caused by Plasmodium falciparum, is urgently needed to combat drug-resistant parasites, now spreading in most parts of the tropics. This article reviews molecular and immunological studies on potential candidate antigens at both the sexual stages and the asexual stages of the parasite development and several vaccination trials of SPf66, a synthetic vaccine being currently undertaken in the field. The identification of immunodominant T cell and B cell epitopes and antigen polymorphism/antigenic variation in the parasite, which obviously constitute major problems to be solved before producing effective vaccines, are discussed.