1. a HIV and Sexually Transmitted Infections Department , Health Protection Agency Centre for Infections , London
2. b Freelance community consultant
3. c In-depth interviewer
4. d HIV & Sexual Health Psychology Services, Mortimer Market Centre , Camden Primary Care Trust , London
5. e Department of Mental Health Sciences , Royal Free and University College Medical School , London
6. f Centre for Sexual Health and HIV Research, Department of Primary Care and Population Sciences , Royal Free and University College Medical School , London
7. g Specialist Reference and Microbiology Division , Health Protection Agency Centre for Infections , London , UK