This epidemiology study is planned to run in parallel with the EPI-MAL-002 and EPI-MAL-003 studies, enrolling from the same HDSS (health and demographic surveillance system) (or equivalent system) populations. The primary objectives are to produce longitudinal estimates of parasite prevalence in humans, and record malaria control measure usage in areas where EPI-MAL-002 and EPI-MAL-003 studies will take place.