1. a Family Health International , Durham, North Carolina, USA
2. b Independent Consultant, Geneva, Switzerland
3. c Centre for the AIDS Programme of Research in South Africa Mailman School of Public Health , Columbia University
4. d Nelson R. Mandela School of Medicine , University of KwaZulu-Natal , Natal, South Africa
5. e Berman Bioethics Institute , Johns Hopkins University , Baltimore, Maryland, USA