AMSc Public Health, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.

BDepartment of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.

CInstitute for Infectious Diseases and Global Health, University of North Carolina at Chapel Hill, Chapel Hill, USA.

DWarwick Medical School, University of Warwick, Coventry, UK.

ECentral Clinical School, Monash University, Melbourne, Vic, Australia.

FMelbourne Sexual Health Centre, Alfred Health, Melbourne, Vic, Australia.

GDepartment of Public Health, The University of Texas at San Antonio, San Antonio, TX, USA.

HDepartment of Population Health, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.

IDepartment of Social Medicine and Health Education, School of Public Health, Nanjing Medical University, Nanjing210093, China.