Resistance in vivo of Plasmodium falciparum to co-trimoxazole in western Uganda.

In the context of the 'integrated management of childhood illnesses' (IMCI) programme the World Health Organization recommends treating children in malarious areas presenting with fever and respiratory symptoms with co-trimoxazole. In order to verify its effectiveness in uncomplicated Plasmodium falciparum malaria we carried out a study in vivo in western Uganda: 180 children under 5 years old were enrolled and treated with 40/8 mg/kg/d co-trimoxazole over 5 d, and 159 could be followed on days 3, 7 and 14. Effectiveness of treatment was found to be significantly different in various parts of the study area. In Bundibugyo District, bordering République Democratique du Congo (Zaire), 59.1% (39/66) of children were clinically cured after 14 d and 56.1% were parasitologically cured. In the east of Kabarole District (43 children), the figures were 76.7% and 65.1%, respectively. In western Kabarole (50 children) the rates were 96.0% and 90.0%, respectively. We conclude that, in view of the high level of clinical failures in parts of the study area, co-trimoxazole should not be used in the IMCI programme for combined treatment of malaria and pneumonia in the region. Assessment of therapeutic effectiveness of antimalarial drugs needs to consider the microepidemiology of resistance.