PYRIMETHAMINE SENSITIVITY IN PLASMODIUM-FALCIPARUM - DETERMINATION INVITRO BY A MODIFIED 48-HOUR TEST

Abstract

Four strains of P. falciparum [from humans] recently isolated in culture were assessed in vitro for their response to pyrimethamine. A simple modified 48-h test was used, which showed 2 strains to be sensitive to the drug in vitro, while the other 2 were resistant at a very high level. In the 2 strains for which relevant clinical information was available the in vivo response to pyrimethamine was corroborated by the in vitro findings. This modified 48-h test is useful for determining patterns of drug sensitivity in laboratory-adapted strains and would be a valuable asset if equally applicable under field conditions.