[1] London Sch Hyg & Trop Med, Dept Hlth Serv Res & Policy, London, England
[2] UCL, Natl Inst Hlth Res Hlth Protect Res Unit NIHR HPR, London, England
[3] Univ Bristol, Bristol Med Sch, Populat Hlth Sci, Bristol, Avon, England
[4] Guys & St Thomas NHS Trust, Dept Infect, London, England
[5] Guys & St Thomas NHS Trust, Emergency Dept, London, England
[6] Guys & St Thomas NHS Trust, Dept HIV GU Med, London, England
[7] Gilead Sci Med Dept, London, England