Transient malaria suppression after mass drug administration with artemisinin-piperaquine in a holoendemic, non-isolated region of Togo

Mass drug administration (MDA) as a malaria control strategy in holoendemic, non-isolated regions of continental Africa lacks robust evidence regarding its ability to sustain malaria reduction. We evaluated the effect of artemisinin-piperaquine (AP) MDA in Togo. In a quasi-experimental study, three monthly AP MDA rounds (Mar–May 2017) were delivered to ~ 160,000 residents across 198 villages in Est-Mono prefecture (intervention zone). Outcomes were compared to ~ 146,000 residents across 182 villages in Anié prefecture (control zone), which received the standard national malaria control programme (NMCP) without MDA. Parasite and gametocyte carriage in children aged 6–60 months was assessed microscopically at baseline, 2 months, and 5 months post-MDA, and health facility data on malaria (2016–2018) were analyzed. Coverage of AP-MDA in the intervention zone ranged from 94 to 96%. AP was well-tolerated, with primarily mild gastrointestinal adverse events. Two months post-MDA, the parasite prevalence in Est-Mono children decreased significantly from 82.1% to 37.7% ( P < 0.001), compared with a small but statistically significant reduction in Anié (83.0% to 76.0%, P < 0.001). However, gametocytemia prevalence remained high and showed no significant change in Est-Mono (6.1% pre-MDA vs. 6.9% post-MDA, P = 0.499) compared to an increase in Anié (7.2% to 10.6%, P = 0.005). Five months post-MDA, the parasite prevalence in Est-Mono rebounded to 72.6% (vs. 82.0% in Anié). Outpatient malaria cases in Est-Mono health facilities during the MDA period (March-June 2017) decreased by 73.5% compared to the same period in 2016, but returned to pre-intervention levels by 2018. AP-MDA was associated with a rapid but transient reduction in malaria prevalence in this holoendemic, non-isolated setting. However, sustained malaria control is likely to require integrating MDA with complementary strategies.