1. Laboratory for Medical Microbiology and Public Health, Hengelo, Overijssel, the Netherlands
2. Department of Internal Medicine, Medisch Spectrum Twente, Enschede, Overijssel, the Netherlands
3. Viroscience, Erasmus University Medical Center, Rotterdam, Zuid-Holland, the Netherlands
4. Center for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, Utrecht, the Netherlands
5. Department of Internal Medicine, Ziekenhuis Groep Twente, Almelo/Hengelo, Overijssel, the Netherlands