Efficacy of artesunate plus amodiaquine, artesunate plus sulfadoxine-pyrimethamine, and chloroquine plus sulfadoxine-pyrimethamine in patients with uncomplicated Plasmodium falciparum in the Comoros Union

Health policy makers in Comoros Union have considered a policy change recommending combination treatment to control malaria. We evaluated the efficacy of three antimalarial drug combinations, taken orally, to enable the authorities to make an evidence-based choice. The study was carried out in patients of 2–70 years old in Moroni, Moheli and Anjouan in 2003. We enrolled 168 patients with uncomplicated malaria from 1097 outpatients screened at the health centres. One hundred and fifty-eight patients, of whom half were under five years old, (mean age = 11.1 ± 13.9 years), were followed up for 14 days. According to PCR adjusted outcome, the therapeutic efficacy of artesunate + amodiaquine (AS + AQ) (n = 54) and artesunate + sulfadoxine-pyrimethamine (AS + SP) (n = 53) was 100%, whereas that of chloroquine + sulfadoxine-pyrimethamine (CQ + SP) was 98% (50/51). The key difference between these treatments was the higher parasite clearance rate on Day 2 obtained with artesunate-containing combinations (P < 0.001). These results provide a baseline for monitoring changes in the susceptibility of Plasmodium falciparum to artesunate + amodiaquine and artesunate + sulfadoxine-pyrimethamine (ACTs) in the Comoros Union. Health policy changes involving the replacement of chloroquine in the Indian Ocean subregion are discussed.