This is a continuous cohort study consisting of 200 participants (one third 6 months old to 5
years, one third 6 to 15 years old, one third ≥ 15 years old) i.e. a new patient will be
recruited (from the same age group) for any patient who develops a Pv infection so that the
cohort will always have 200 patients for 3 years. Each patient will be actively followed-up
every 8 weeks until Plasmodium vivax infection occurs but the duration of follow up and the
number of follow up visits for each patient will vary depending on when or if a vivax
infection occurs and when the patient is recruited. Therefore, the minimum follow up period
for each patient will be 6 months or time to vivax infection and the maximum will be 3 years
if a patient does not get vivax infection and is recruited at the beginning of the study.