University of Glasgow - Institute of Health and Wellbeing, University of Glasgow - Boyd Orr Centre for Population and Ecosystem Health, University of Glasgow - School of Geographical & Earth Sciences, University of Glasgow - Institute of Health and Wellbeing, University of Glasgow - The Boyd Orr Centre for Population and Ecosystem Health, University of Glasgow - The Boyd Orr Centre for Population and Ecosystem Health, University of Glasgow - MRC/CSO Social and Public Health Sciences Unit, Catholic University of Health and Allied Sciences/Bugando Medical Centre - Department of Microbiology and Immunology, Kilimanjaro Christian Medical University College, Kilimanjaro Christian Medical Centre - Kilimanjaro Clinical Research Institute, Kilimanjaro Christian Medical Centre - Kilimanjaro Clinical Research Institute, The Nelson Mandela African Institution of Science and Technology, University of Glasgow - The Boyd Orr Centre for Population and Ecosystem Health, University of Glasgow - MRC/CSO Social and Public Health Sciences Unit, Catholic University of Health & Allied Sciences and Kilimanjaro Christian Medical University College - Kilimanjaro Clinical Research Institute