1. Department of Psychology, School of Human and Community Development, University of the Witwatersrand, Johannesburg, South Africa
2. Perinatal HIV Research Unit (PHRU), School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
3. Health Systems Research Unit, South African Medical Research Council (SAMRC), South Africa
4. African Social Sciences Unit of Research and Evaluation (ASSURE), Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa