1. Centre for Geographic Medicine Research (Coast), Kilifi, Kenya;
2. Department of Paediatrics, University of Oxford, Oxford, United Kingdom;
3. Muhumbili University College of Health Sciences, Dar-es-Salaam, Tanzania;
4. Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom; and
5. INDEPTH Network of Demographic Surveillance Sites, Accra, Ghana