Development of a blood culture medium and a standard in vitro microtest for field-testing the response of Plasmodium falciparum to antifolate antimalarials.

The history of the development of the WHO standard in vitro microtest is summarized, and the rationale and methodology that were used to broaden the system for the testing of antifolate drugs such as sulfadoxine and pyrimethamine (in addition to chloroquine, mefloquine, quinine and amodiaquine) are explained. Additional information is given concerning the composition of the basic and replenishment test kits and the means of procuring them.