Introduction: A large fraction of Plasmodium infections do not cause clinical signs and symptoms of disease and persist at densities in blood that are not detectable by microscopy or rapid diagnostic tests. These infections may be critical as a transmission reservoir in areas of low malaria endemicity.
Aim: To assess the safety and coverage of mass drug administration (MDA) and the magnitude and duration of its effect on the interruption of P. falciparum transmission.
Methods: Following community mobilisation activities, two malaria-endemic villages were randomized in April 2016 to three, monthly rounds of MDA (intervention) and another two villages to control. During MDA, a three-day regimen of 7mg/kg dihydroartemisinin and 55mg/kg piperaquine phosphate plus a single low dose of primaquine was administered to the entire village population. Cross-sectional surveys were conducted in all four villages at three-monthly intervals for 12 months during which blood was tested for Plasmodium by quantitative polymerase chain reaction. Treatment records with travel histories were collected from village health workers. Rates of asymptomatic and clinical falciparum malaria were calculated.
Results: Between 85% and 88% of 1006 residents participated in the mass drug administrations in the two intervention villages. All tested participants had cleared their infections 3 months after the start of the MDAs while the parasitaemia prevalence persisted in the control villages. Two severe adverse reactions were recorded. The first assessment of the impact of the intervention will be presented.
Conclusion: Mass drug administrations with dihydroartemisinin-piperaquine plus a single low dose of primaquine was feasible, safe and well-received in remote villages of Lao PDR. The consequences of the impact assessment will be discussed.