High efficacy of two artemisinin-based combinations: Artesunate + sulfadoxine-pyrimethamine and artemether-lumefantrine for falciparum malaria in Yemen

Background: Artesunate + sulfadoxine-pyrimethamine (AS + SP) has been the first-line treatment and artemether-lumefantrine (AL) the second-line treatment for uncomplicated falciparum malaria in Yemen since 2005. This paper reports the results of studies conducted to monitor therapeutic efficacy of these two drugs in sentinel sites in Yemen. Methods: Eight therapeutic efficacy studies were conducted in six sentinel sites during the period 2009-2013 in Yemen. Five studies were for the evaluation of AS + SP (total of 465 patients) and three studies (total of 268 patients) for the evaluation of AL. The studies were done according to standard WHO protocol 2009 with 28-day follow-up. Results: In the evaluation of AS + SP, the PCR-corrected cure rate was 98 % (95 % CI 92.2-99.5 %) in one site and 100 % in all of the other four sites. In the sites where AL was evaluated, the PCR-corrected cure rate was 100 % in all the sites. All patients were negative for asexual parasitaemia on day 3 in both the AS + SP and the AL groups. There was a higher rate of clearance of gametocytaemia in the AL-treated group when compared with the AS + SP groups from day 7 onwards. Conclusion: AS + SP remains the effective drug for uncomplicated falciparum malaria in Yemen. AL is also highly effective and can be an appropriate alternative to AS + SP for the treatment of falciparum malaria. AL demonstrated a higher efficacy in clearing microscopic gametocytaemia than AS + SP.