1. Lecturer, Division of Social and Behavioural Sciences, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
2. Associate Professor and Head, Division of Social and Behavioural Sciences, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
3. Assistant Professor, Department of Behavioral and Social Sciences, School of Public Health, International Health Institute, Brown University, Providence, RI, USA