Assessment of the Therapeutic Efficacy of Two Artemisinin-Based Combinations in the Treatment of Uncomplicated Falciparum Malaria among Children Under 5 Years in Four District Hospitals in Sierra Leone

Abstract

Plasmodium falciparum has developed resistance to almost every class of antimalarial compounds. As a result of this, the World Health Organization has recommended artemisinin-based combination therapy as first line treatment for P. falciparum malaria. There is however need for the continuous monitoring of the efficacy of these antimalarials in order to provide timely information on trends of the emergence of resistant strains. We assessed the therapeutic efficacy of oral artesunate – amodiaquine and artemether-lumefantrine combinations in the treatment of uncomplicated P. falciparum malaria in four District Hospitals in Sierra Leone. A total of 320 children under five years partiiccipated in the study sites (Kenema, Rokupa, Bo and Makeni). Oral Artesunate-amodiaquine combination was administered to participants in Kenema and Rokupa whilst Artemetherlumefantrine combination was administered to participants in Bo and Makeni. The new WHO Protocol for recruitment of participants in therapeutic efficacy trials in high transmission zones was adopted for the study with filter paper blood samples taken from each participant on days 0 and 28 to distinguish between treatment failure and new infection. When uncorrected for PCR analysis, 96% (95% CI: 902 – 989) and 100% (95% CI:63.1 – 100) responses were obtained in Kenema and Bo respectively with Artesunate-amodiaquine combination whilst 94.3% (CI 95 : 88.1 – 979) and 100% (95% CI: 96.5 – 100) were obtained with Artemether-lumefantrine combination in Bo and Makeni respectively. When corrected for PCR on the other hand, a 100% (95% CI) Adequate Clinical and Parasitological Response was obtained for the two drugs in all four study sites. Results from this study indicate that both Artesunate-amodiaquine and Artemether-lumefantrine combinations remain highly efficacious in Sierra Leone with presently no observed emergence of resistant strains to both drugs.

Keywords: Artemisinin-based combination, uncomplicated falciparum malaria, children, Sierra Leone