1. Laboratory for Microbiology and Infection Control, Amphia Hospital, Breda, the Netherlands
2. Netherlands Centre for Infectious Disease Control, National Institute for Public Health and the Environment (Rijksinstituut voor Volksgezondheid en Milieu, RIVM), Bilthoven, the Netherlands
3. Dutch Institute for Healthcare Improvement (CBO), Utrecht, the Netherlands
4. Department of Microbiology and Infection Control, VU University Medical Center (VU medisch centrum, VUmc), Amsterdam, the Netherlands