A comparative study on the efficacy of artesunate plus sulphadoxine/pyrimethamine versus artemether-lumefantrine in eastern Sudan

BACKGROUND: A combination of artesunate (AS) plus sulphadoxine/pyrimethamine (SP) as first-line and artemether-lumefantrine (AL) as second-line treatment are currently recommended against uncomplicated P. falciparum infection in Sudan. However, there is limited information on the efficacy of ACTs in the country and only one report of PCR-corrected results for AS/SP only. METHODS: The WHO protocol for the assessment of antimalarial drug efficacy for the treatment of uncomplicated falciparum malaria was employed. Artesunate plus sulphadoxine/pyrimethamine (AS/SP) was compared to artemether-lumefantrine (AL) in a 28-day follow up. Samples that were classified as early treatment failure (ETF), late treatment failure (LCF) or late parasitological failure (LPF) were genotyped for msp-1 and msp-2 genes to differentiate recrudescence from reinfection. RESULTS: A total of 178 patients were screened and 160 met the enrolment criteria and were recruited to the study of which 157 (98.1%) completed the follow up and had an analysed treatment outcome. On the AS/SP arm, three (0.038%) patients were lost during the follow-up, two on day 1 and one on day 7, and 77 (96.3) completed the study, while all 80 (100%) patients completed the follow up in the AL arm. In the per protocol analysis for AS/SP the treatment outcome for patients who completed the follow-up were as follows: adequate clinical and parasitological response (ACPR); 84.4% ETF; 1.3%, LCF; 3.9%, (LPF); 10.4%. For the AL arm the out come was as follows, ACPR; 90%, ETF; 0%, LCF; 6.3% and LPF; 3.8%. However, when PCR-corrected, 6.5% (5/77) of patients treated with AS/SP maintained parasites from their primary infection, while (7/80) in the AL group maintained their initial parasite genotype. Therefore, PCR-corrected efficacy was 93.5% in the AS/SP treated group and for AL it was 91.3%. CONCLUSION: Both AS/SP and AL are highly effective for the treatment of uncomplicated falciparum malaria in eastern Sudan. However, AS/SP appears to have a slightly higher efficacy than AL, this may be due to patient compliance with the repeated dose rather than drug efficacy.