1. Department of Internal Medicine, Division of Infectious Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
2. Department of Infectious Diseases, Public Health Service Amsterdam, Amsterdam, the Netherlands
3. Stichting HIV Monitoring, Amsterdam, Netherlands
4. Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands
5. Department of Medical Microbiology, Haaglanden Medical Centre, The Hague, the Netherlands