Short-term impact of mass drug administration with dihydroartemisinin plus piperaquine on malaria in southern province Zambia: A cluster-randomized controlled trial

Abstract

Background. Mass drug administration (MDA) using dihydroartemisinin plus piperaquine (DHAp) represents a potential strategy to clear Plasmodium falciparum infections and reduce the human parasite reservoir. Methods. A cluster-randomized controlled trial in Southern Province, Zambia, was used to assess the short-term impact of 2 rounds of community-wide MDA and household-level (focal) MDA with DHAp compared with no mass treatment. Study end points included parasite prevalence in children, infection incidence, and confirmed malaria case incidence. Results. All end points significantly decreased after intervention, irrespective of treatment group. Parasite prevalence from 7.71% at baseline to 0.54% after MDA in lower-transmission areas, resulting in an 87% reduction compared with control (adjusted odds ratio, 0.13; 95% confidence interval, .02-.92; P = .04). No difference between treatment groups was observed in areas of high transmission. The 5-month cumulative infection incidence was 70% lower (crude incidence rate ratio, 0.30; 95% confidence interval, .06-1.49; P = .14) and 58% lower (0.42; .18-.98; P = .046) after MDA compared with control in lower-and higher-transmission areas, respectively. No significant impact of focal MDA was observed for any end point. Conclusions. Two rounds of MDA with DHAp rapidly reduced infection prevalence, infection incidence, and confirmed case incidence rates, especially in low-transmission areas.