1. Department of Epidemiology Brown University School of Public Health Providence Rhode Island USA
2. Division of Epidemiology and Biostatistics School of Public Health and Family Medicine University of Cape Town Cape Town South Africa
3. Centre for Infectious Disease Epidemiology & Research School of Public Health & Family Medicine University of Cape Town Cape Town South Africa
4. ICAP at Columbia University Mailman School of Public Health Columbia University New York New York USA
5. Department of Obstetrics & Gynaecology University of Cape Town and New Somerset Hospital Cape Town South Africa
6. Department of Pediatrics Vagelos College of Physicians & Surgeons Columbia University New York New York USA