Most human
Plasmodium infections in western Kenya are asymptomatic and are believed to contribute importantly to
malaria transmission. Elimination of
asymptomatic infections requires active treatment approaches, such as mass testing and treatment (
MTaT) or
mass drug administration (MDA), as infected persons do not seek care for their
infection. Evaluations of community-based approaches that are designed to reduce
malaria transmission require careful attention to study design to ensure that important effects can be measured accurately. This manuscript describes the study design and methodology of a cluster-randomized controlled trial to evaluate a
MTaT approach for
malaria transmission reduction in an area of high
malaria transmission. Ten health facilities in western Kenya were purposively selected for inclusion. The communities within 3 km of each health facility were divided into three clusters of approximately equal population size. Two clusters around each health facility were randomly assigned to the control arm, and one to the intervention arm. Three times per year for 2 years, after the long and short rains, and again before the long rains, teams of community health volunteers visited every household within the intervention arm, tested all consenting individuals with
malaria rapid diagnostic tests, and treated all positive individuals with an effective
anti-malarial. The effect of mass testing and treatment on
malaria transmission was measured through population-based longitudinal cohorts, outpatient visits for clinical
malaria, periodic population-based cross-sectional surveys, and entomological indices.