The Medical Research Council (MRC) Unit, The Gambia have recruited severe malaria cases, healthy controls and parents for Consortial Project 1. Transmission of malaria in The Gambia is seasonal. The long dry season lasts from November-June with a short rainy season from July-October. Morbidity and mortality from malaria follows this pattern. Both occur more frequently during the rainy season with a peak in October. P. falcuparium is the dominant species, being responsible for all severe disease and for over 95% of clinical attacks. A few cases of clinical malaria are caused by P. malariae. 

Description of study population - Cases

Cases consist of children (0-15 years) with severe malaria. The children were recruited from patients admitted to the Royal Victoria Teaching Hospital (RVTH) and the Medical Research Council (MRC) wards between 1996 and 2007. The RVTH is located in the capital, Banjul, and is The Gambia's main referral hospital. Patients come from all over the country, with the majority from the western part. The MRC wards are located in the main research site of the MRC in Fajara.

Severe malaria was defined by the presence of asexual parasitemia and any of the following: cerebral malaria (Blantyre coma score of 2 or below), severe anaemia (haemoglobin <6 g/dL or hematocrit <18%), respiratory distress (respiratory rate >40 with 2 of the following: nasal flaring, intercostal indrawing, subcostal recession and grunting), repeated generalised convulsions, hypoglycaemia (blood glucose <2.2mmol/l or <40mg/dl), renal failure (urine output <12ml/kg/day), haemoglobinuria, jaundice, prostration, hyperparasitaemia (>=500 parasites/HPF), hyperpyrexia, circulatory collapse, cold extremities, rapid pulses, systolic blood pressure below 50mmHg.

Description of study population - Controls

Controls consist of cord blood samples recruited from various labour wards, primarily in the western division of The Gambia, between 1999 and 2007.

Description of study population - Parents

Blood samples from the parents of some of the severe malaria cases and mothers of some of the controls were collected.