1. a Research Department of Infection and Population Health , University College London , London , UK
2. b Thoracic Medicine/Infectious Diseases , Royal Free NHS Trust , London , UK
3. c Department of HIV/Genitourinary Medicine , Brighton and Sussex University Hospitals NHS Trust , Brighton , UK
4. d Centre for the Study of Sexual Health and HIV , Homerton University Hospital NHS Foundation Trust , London , UK
5. e Department of Genitourinary Medicine , Mortimer Market, London , UK
6. f Department of Palliative Care, Policy and Rehabilitation , Kings College London , London , UK