Study to Understand Resistance to Malaria in Burkina Faso

The University of Rome together with CNRFP and Centre Médicale St. Camille have recruited malaria cases and healthy controls to contribute to Consortial Project 1. These individuals were collected from the capital of Burkina Faso, Ouagadougou, and surrounding rural zones. Malaria in these areas is endemic with a seasonal pattern characterized by a high transmission rainy season (Jun-Oct) and a low transmission dry season (Nov-May). Differences exist in malaria transmission levels between urban and rural areas: entomological inoculation rates vary from 1 to 10 per person per year in urban areas of Ouagadougou, and from 50 to 500 in the surrounding rural zones. The main malaria vectors are Anopheles gambiae, A. arabiensis, and A. funestus. The great majority of the population belongs to the Mossi ethnic group.

Description of study population - Cases

Cases consist of children (1month-15yrs) of Mossi ethnicity, admitted to hospital with signs of severe or uncomplicated malaria. The children were recruited from patients admitted to the paediatric ward of three hospitals in Ouagadougou during the high malaria transmission seasons of 1993-94.

The criteria for inclusion followed the definitions stated by the World Health Organization. Severe malaria was defined by the presence of P. falciparum in the thick blood film associated with at least one of the following conditions: prostration (incapacity of child to sit without help in absence of coma), unrousable coma (Blantyre coma score of 2 or below), repeated generalized convulsions (more than two episodes in preceding 24 hr), severe anaemia (haemoglobin <5 g/dL), hypoglycemia (<40 mg/dL), pulmonary edema/respiratory distress, spontaneous bleeding, and renal failure (plasma creatinine >3 mg/dL). Children with other detectable infections or causes for clinical presentation were not included in the study.

Description of study population - Controls

Controls are comprised of children (0-6 yrs) of Mossi ethnicity and no signs of severe or uncomplicated malaria. They were recruited from rural villages south-west of Ouagadougou (area of Balonguin) during a cross-sectional survey conducted in Aug 2004. Children presenting with any clinical sign to direct physical examination were excluded from the study.