University of Greenwich, University of Cambridge, University of Warwick, The Gambia at London School of Hygiene and Tropical Medicine, affiliation not provided to SSRN, University of East London, Queen Mary University of London, The Gambia at London School of Hygiene and Tropical Medicine, London School of Hygiene & Tropical Medicine - Medical Research Council Unit: The Gambia, affiliation not provided to SSRN, University of Oxford, University College London, King’s College London - Department of Women and Children’s Health and University of Cambridge