Efficacy of three artemisinin combination therapies for the treatment of uncomplicated Plasmodium falciparummalaria in the Republic of Congo

ABSTRACT

Background: Presented here are the results of a comparative trial on the efficacy of three artemisinin-based combinations conducted from May to October 2004; in Pool Province; Republic of Congo.Methods: The main outcome was the proportion of cases of true treatment success at day 28. Recrudescences were distinguished from re-infections by PCR analysis. A total of 298 children of 6-59 months were randomized to receive either artesunate + SP (AS+SP); artesunate + amodiaquine (AS+AQ) or artemether + lumefantrine (AL); of which 15 (5) were lost to follow-up. Results: After 28 days; there were 21/85 (25) recurrent parasitaemias in the AS+SP group; 31/97 (32) in the AS+AQ group and 13/100 (13) in the AL group. The 28-day PCR-corrected cure rate was 90.1[95CI 80.7-95.9] for AS+SP; 98.5[95CI 92.0-100] for AS+AQ and 100[95.8-100] for AL; thereby revealing a weaker response to AS+SP than to AL (p=0.003) and to AS+AQ (p=0.06). A potential bias was the fact that children treated with AL were slightly older and in better clinical condition; but logistic regression did not identify these as relevant factors. There was no significant difference between groups in fever and parasite clearance time; improvement of anaemia and gametocyte carriage at day 28. No serious adverse events were reported. Conclusions: Considering the higher efficacy of AL as compared to AS+SP and the relatively high proportion of cases with re-infections in the AS+AQ group; we conclude that AL is clinically more effective than AS+SP and AS+AQ in this area of the Republic of Congo. Implementation of the recently chosen new national first-line AS+AQ should be monitored closely