1. MRC/UVRI and LSHTM Uganda Research Unit, Uganda
2. School of Public Health, University of Sydney, Australia; Department of Global Health and Development, London School of Hygiene and Tropical Medicine, UK
3. MRC/UVRI and LSHTM Uganda Research Unit, Uganda; Child Health and Development Centre, Makerere University, Uganda
4. MRC/UVRI and LSHTM Uganda Research Unit, Uganda; Department of Global Health and Development, London School of Hygiene and Tropical Medicine, UK