Methods of data collection

The following data collection methods were used to accomplish this study.

The socio-demographic and other malaria risk factors were collected using pre-tested structured questionnaires. For those study participants who had difficulty in reading and filling out the questionnaires, face-to-face interviews, based on questionnaire, were made by trained laboratory technicians. A self-administered questionnaire was used for adult study participants aged above 18 years who were capable of reading whereas a face-to-face interview was made with parents/guardians of children.

Finger-prick blood samples were collected using a strictly disposable sterile blood lancet. Thick and thin blood films were prepared for the purpose of checking the presence of Plasmodium parasites and species identification, respectively, according to WHO guidelines [47]. All blood films were stained with 3% Giemsa and examined by two experienced laboratory technicians independently for the presence of Plasmodium infection and species identification. If there was controversy on the results observed by the two, a third person resolved the disagreement. Microscopy or Rapid Diagnostic Test (RDT, Access Bio Korea, Inc, Korea, Seoul) was used for diagnosis of study participants.