1. Center for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, the Netherlands
2. Laboratory for Medical Microbiology and Public Health, Hengelo, the Netherlands
3. Public Health Service, Twente, the Netherlands
4. Public Health Service region Utrecht, Zeist, the Netherlands
5. Department of Medical Microbiology, Leiden University Medical Center, Leiden, the Netherlands
6. Department of Viroscience, Erasmus Medical Centre, Rotterdam, the Netherlands
7. Department of Virology, University Medical Center Utrecht, Utrecht, the Netherlands
8. Laboratory of Medical Microbiology and Immunology, St Elisabeth Hospital, Tilburg, the Netherlands
9. Public Health Service, Department of Infectious Diseases, Amsterdam, the Netherlands
10. Department of Medical Microbiology, Academic Medical Center, Amsterdam, the Netherlands
11. Department of Medical Microbiology, Division of Clinical Virology, University Medical Center Groningen, Groningen, the Netherlands