1. HIV/STD Unit, Institute of Tropical Medicine, University of Antwerp, Antwerp, Belgium
2. Division of Infectious Diseases and HIV Medicine, University of Cape Town, Cape Town, South Africa
3. STI/HIV Epidemiology and Control Unit, Institute of Tropical Medicine, Antwerpen, Belgium
4. Center for Statistics, Hasselt University, Diepenbeek, Belgium
5. Centre for Health Economic Research and Modelling Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Wilrijk, Belgium