1 Maternal and Neonatal Health, Clinton Health Access Initiative, Boston, MA 02127, USA. Electronic address: [email protected].
2 Maternal and Neonatal Health, Clinton Health Access Initiative, Boston, MA 02127, USA.
3 Maternal, Neonatal and Child Health, Bill & Melinda Gates Foundation, Seattle, WA, USA.
4 International Diagnostics Centre, London School of Hygiene & Tropical Medicine, London, UK.
5 HIV Program, World Health Organization, Geneva, Switzerland.
6 Sexually Transmitted Infection Program, World Health Organization, Geneva, Switzerland; Division of Sexually Transmitted Disease Prevention, US Centers for Disease Control and Prevention, Atlanta, GA.