1. a Department of Global Health and Development , London School of Hygiene and Tropical Medicine , London , UK
2. b CHARME-India Project , Bangalore , India
3. c URESP, Centre de recherche du CHA universitaire de Québec , Québec , Canada
4. d Indian Institute of Health and Family Welfare(IIHFW) , Hyderabad , Andhra Pradesh , India
5. e Department of HIV & Sexually Transmitted Infections , Health Protection Agency , London , UK