This is an observational study to determine the burden of malaria in rural Malian infants. Infants will be identified during a village-wide census and at Expanded Program for Immunization (EPI) visits. After obtaining community consent, eligible infants' parents will be invited to bring infants to the clinic for screening. Enrolled infants will receive a baseline evaluation and monthly visits during the rainy season at which times they will receive interim evaluations and heel, toe, or finger pricks for determinations of hemoglobin, thick and thin blood films, malaria antibody titers (at first and last visit for each transmission season), and hemoglobin typing at one visit. Study subjects will also receive a weekly home visit to determine if they are well or ill. If ill or febrile at any visit, or if they present to the clinic for an unscheduled visit, subjects will receive a history and physical examination, heel, toe, or finger pricks for determinations of hemoglobin, thick and thin blood films, filter paper blood collection and an RDT for malaria. Diagnosis and treatment of malaria will be performed according to Mali National Malaria Control Program (NMCP) guidelines. Diagnosis and treatment of other conditions will be performed as determined by the treating clinician.