A randomized cluster trial of MST study using dihydroartemisinin-piperaquine plus primaquine (DHP + PQ) will be conducted in some villages at the Belu regency, Nusa Tenggara TImur province, Central Indonesia. There will be three arms in the study, i.e. (1) intervention arm of mass screening and treatment with interval of 6 weeks; (2) intervention arm of mass screening and treatment with interval of 3 months and (3) control arm without mass screening and treatment. The intervention arm with 6 weeks interval represents a new proposed method to detection malaria infections, while the intervention arm with 3 month interval represents the Ministry of Health current policy of active case detection in Indonesia, and the third arm will serve as the control for Ministry of Health's policy.