1. Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands.
2. Department of Internal Medicine, Division of Infectious Diseases, Tropical Medicine, and AIDS, Academic Medical Center, Amsterdam, The Netherlands.
3. Department of Social Medicine, Academic Medical Center, Amsterdam, The Netherlands.
4. Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.
5. Department of Internal Medicine, Hospital Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.
6. Department of Internal Medicine and Infectious Diseases, University Medical Center Utrecht, Utrecht, The Netherlands.