1. Senior Lecturer, Department of Sociology, University of the Witwatersrand, Johannesburg, South Africa; Director, Sarraounia Public Health Trust, 20 4th Avenue, Parktown North, Johannesburg, 2193, South Africa. Correspondence:
2. Social Scientist, Sarraounia Public Health Trust, Johannesburg, South Africa
3. Social Scientist, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
4. School of Public Health, University of Cape Town, Cape Town, South Africa
5. Social Scientist, School of Public Health, University of Cape Town, Cape Town, South Africa
6. Professor, Life Sciences Building, South African Bioinformatics Institute, University of the Western Cape, Bellville, South Africa
7. Professor, School of Public Health, University of Cape Town, Cape Town, South Africa
8. Professor, Warwick Medical School, UK; Professor, Centre for Health Policy, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
9. Director of Maternal and Child Health, Wits RHI, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
10. Associate Professor, School of Public Health, University of Cape Town, Cape Town, South Africa
11. Independent research consultant, Toronto, Canada; Associate Faculty, Johns Hopkins School of Public Health, Baltimore, MD, USA