affiliation not provided to SSRN, Makerere University, Makerere University, Addis Ababa University, Moi University - School of Medicine, Harvard University, Harvard T.H. Chan School of Public Health - Department of Epidemiology, Moi Teaching and Referral Hospital, Kenya Medical Research Institute (KEMRI), Harvard T.H. Chan School of Public Health - Department of Epidemiology, Moi Teaching and Referral Hospital, Makerere University, affiliation not provided to SSRN, University of Oxford, affiliation not provided to SSRN, Harvard T.H. Chan School of Public Health - Department of Epidemiology, Harvard T.H. Chan School of Public Health - Department of Epidemiology, Addis Ababa University, Nelson Mandela University, University of Cape Town (UCT) - Neuroscience Institute and Harvard University - Harvard Medical School