1. MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), Faculty of Health Sciences, School of Public Health, University of the Witwatersrand , Johannesburg , South Africa
2. Department of Global Public Health and Primary Care, University of Bergen , Bergen , Norway
3. Division of Epidemiology and Biostatistics, School of Public Health, University of the Witwatersrand , Johannesburg , South Africa
4. Directorate of Library Services, Muhimbili University of Health and Allied Sciences , Dar es Salaam , Tanzania
5. Department of Physiology, School of Biomedical Sciences, Muhimbili University of Health and Allied Sciences , Dar es Salaam , Tanzania
6. Department of Internal Medicine, University of Botswana and Princess Marina Hospital , Gaborone , Botswana
7. Wellstar College of Health and Human Services, Kennesaw State University , Kennesaw, GA , USA
8. Department of Emergency Medicine, Duke School of Medicine/Duke Global Health Institute, Duke University , Durham, NC , USA
9. Department of Family Medicine and Primary Care, University of the Witwatersrand , Johannesburg , South Africa