Efficacy of sulfadoxine-pyrimethamine for the treatment of uncomplicated falciparum malaria in Ethiopia

OBJECTIVE: To assess the status of the therapeutic efficacy of sulfadoxine-pyrimethamine for the treatment of uncomplicated falciparum malaria to enable evidence based policy decisions. DESIGN: The study used the new WHO (2003) protocol for the assessment of the therapeutic efficacy of anti-malarial drugs. SETTING: Eleven health facilities located in malarious areas with seasonal transmission. SUBJECTS: Patients aged six months and above who presented to the health facilities for febrile illness and for whom consent was obtained to participate in the study after fulfilling the inclusion criteria were enrolled in the study. MAIN OUTCOME MEASURES: Proportion of treatment failures. RESULTS: In eleven (90.9%) of the sites, where adequate sample was collected, a total of 598 subjects were enrolled and 487 (81.4%) completed the follow-up. A mean treatment failure rate of 35.9% (95% confidence interval CI 31.8, 40.3) on the 14 days follow-up and 71.7% (95% CI 67.5, 75.9) on the 28-days follow-up was recorded (not PCR corrected). The mean clinical failure on the 14-days follow-up was 20.9% (95% CI 17.5, 24.7) and 70% (n=10) sites had aggregated clinical failure rates higher than 15%, while in 80% (n=10) sites the total treatment failure exceeded 25%. There was no significant difference in treatment failure rates in areas with malaria transmission duration of six months and above as compared to areas with below six months of transmission (odds ratio OR = 0.9, 95% CI 0.43,1.83 p = 0.75). The difference in mean treatment failure between the or =15 years of age was not significant (OR 0.8, 95% CI 0.39,1.67 P = 0.54). CONCLUSION: The level of treatment failure detected is much higher than the WHO recommended tolerable levels. The findings, therefore, strongly indicate the need for an immediate review of the existing national anti-malarial treatment guideline.