1. Group HIV and Sexual Health, Department of Public Health, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
2. Faculty of Psychology, University of Vienna, Vienna, Austria
3. Epidemiology of Infectious Diseases Unit, Department of Public Health and Surveillance, Sciensano - Belgian Scientific Institute of Public Health, Ixelles, Belgium
4. HIV/STI clinic, Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
5. General Practitioner, Opglabbeek, Belgium
6. ELIZA - Center for General Practice, Department of Primary & Interdisciplinary Care Antwerp, University of Antwerp, Antwerp, Belgium