1. Departments of Paediatrics, College of Medicine, University of Ibadan, and University College Hospital Ibadan
2. Departments of Medicine, College of Medicine, University of Ibadan, and University College Hospital Ibadan
3. Departments of Pathology, College of Medicine, University of Ibadan, and University College Hospital Ibadan
4. Institute of Child Health, College of Medicine, University of Ibadan
5. Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK