1. University of Cape Town; Public Health and Family Medicine, Faculty of Health Sciences; Faculty of Haelth Sciences Anzio Road Observatory Cape Town South Africa 7925
2. University of Cape Town; Department of Public Health and Primary Health Care; Department of Public Health and Primary Health Care UCT Medical School, Anzio Road Observatory 7925 Western Cape South Africa
3. University of cape Town; Public Health and Family Medicine, Faculty of Health Sciences; Faculty of Health Sciences Anzio road Observatory Cape Town South Africa 7925
4. University of the Witwatersrand; Reproductive Health & HIV Research Unit; Westridge Medical Centre 95 Jan Smuts Highway Durban South Africa 4091
5. University of the Witwatersrand; Department of Obstetrics and Gynaecology; Westridge Medical Centre 95 Jan Smuts Highway Mayville Durban South Africa 4091
6. Stellenbosch University; Biochemistry; University of Stellenbosch Van der Byl street Stellenbosch South Africa 7600
7. Medical Research Council; Biostatistics Unit; Box 19070 Tygerberg Cape Town Cape Province South Africa 7505