[Standardisation of the in vitro chemosensitivity test for Plasmodium falciparum ]

Reliable in vitro tests are needed to study the epidemiology, pharmacology, genetics and the treatment of Falciparum malaria. We have studied the reproducible nature of an in vitro method using either patients blood or a continuous strain with which we did 254 chemosensitivity tests with chloroquine, mefloquine and quinine. The method is based on ED50 determination which is done by assessing the plasmodial maturation on thin blood film after 24-48 hours incubation. This method is simple to carryout but long to interpret. It has proved reliable and sensitive enough to be used for the proposed studies. The blood group, the limited variations of erythrocyte concentrations, of the composition and volume of the culture medium, of the atmosphere and of the incubation time had little influence on the ED50. It was considered that 47 p. cent of the tests could be interpreted and that this percentage could be improved with a better understanding of the in vitro behaviour of P. falciparum.