Chloroquine sensitivity of Plasmodium falciparum in Ethiopia. II. Results of an in vitro test.

Field trials were performed in two areas of Ethiopia with the Rieckmann in vitro test for chloroquine sensitivity of Plasmodium falciparum. Blood cultures from 82 test subjects showed growth of trophozoites to the schizont stage in control vials. Growth in test vials occurred in 21 cultures incubated with chloroquine at concentrations of 0.5 nanomoles or more per ml of blood. In vitro results confirm previous results obtained with an in vivo test.