1. Department of Medical Microbiology, Division of Clinical Virology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
2. Laboratory for Medical Microbiology, St Elisabeth Hospital, Tilburg, the Netherlands
3. Center for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
4. Department of Medical Microbiology, Academic Medical Center, Amsterdam, the Netherlands
5. Department of Medical Microbiology, Leiden University Medical Center, Leiden, the Netherlands
6. Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
7. Department of Virology, Erasmus Medical Centre, Rotterdam, the Netherlands