1 London School of Hygiene and Tropical Medicine, London, UK.
2 Kenya Medical Research Institute (KEMRI), Centre for Geographic Medicine Research-Coast (CGMRC) and KEMRI-Wellcome Trust Research Programme (KWTRP), Kilifi, Kenya.
3 Aga Khan University, Nairobi, Kenya.
4 Unit of Health Sciences, Faculty of Social Sciences, Tampere University, Tampere, Finland.
5 Medical Research Council Unit, The Gambia at London School of Hygiene and Tropical Medicine, Banjul, Gambia.
6 Liverpool School of Tropical Medicine, Liverpool, UK.