1. Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
2. Department of Global Health, Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
3. Departments of Medicine, Global Health, and Epidemiology, University of Washington, Seattle, WA, USA
4. Department of Behaviour and Social Sciences, Brown University School of Public Health, RI, USA
5. Centre for Topical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK