1. Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne , Melbourne , Australia
2. HIV/STI Unit, Institute of Tropical Medicine , Antwerp , Belgium
3. Division of Infectious Diseases and HIV Medicine, University of Cape Town , Cape Town , South Africa
4. WHO Collaborating Centre for Gonorrhoea and Other STIs, National Reference Laboratory for STIs, Department of Laboratory Medicine, Örebro University , Örebro , Sweden
5. Faculty of Population Health Sciences, Institute for Global Health, University College London , London , UK