1. 1Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Fajara, Kombo, The Gambia;
2. 2Centre for International Health, University of Otago, Dunedin, New Zealand;
3. 3London School of Hygiene & Tropical Medicine, London, United Kingdom;
4. 4Medicines Control Agency, Kairaba Avenue, Kombo, The Gambia;
5. 5Regional Health Team, Upper River Region, Basse, URR, The Gambia;
6. 6Department of Paediatrics: Child and Youth Health, University of Auckland, Auckland, New Zealand;
7. 7Murdoch Childrens Research Institute, Parkville, Melbourne, Victoria, Australia;
8. 8Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia