1. University of Cape Town; School of Child and Adolescent Health; Institute of Infectious Disease and Molecular Medicine Anzio Road, Observatory Cape Town South Africa 7925
2. Liverpool School of Tropical Medicine; Child and Reproductive Health Group; Pembroke Place Liverpool UK L3 5QA
3. University of Cape Town; Institute of Infectious Disease and Molecular Medicine (IIDMM); Anzio Road, Observatory Cape Town South Africa 7925
4. University of Malawi; Department of Public Health; College of Medicine; Blantyre Malawi
5. University Hospitals of Leicester NHS Trust; Directorate of Women's, Perinatal and Sexual Health Services; Leicester UK
6. State University of New York at Buffalo; Department of Medicine; ECMC CC-142 462 Grider Street Buffalo NY USA 14215
7. World Health Organization; Department of HIV/AIDS; Geneva Switzerland