1. a Department of Paediatrics, College of Medicine , University of Ibadan , Ibadan , Nigeria
2. b AIDS Prevention Initiative in Nigeria (APIN) Plus , University College Hospital , Ibadan , Nigeria
3. c APIN Plus/Harvard PEPFAR , Lagos , Nigeria
4. d APIN Plus/Harvard PEPFAR , Boston , USA
5. e Harvard School of Public Health , Boston , USA