1. Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven
2. Department of Epidemiology and Biostatistics, Maastricht University Medical Centre, The Netherlands
3. Department of Pathology, Vrije Universiteit Amsterdam, Amsterdam University Medical Centres, Maastricht University Medical Centre, The Netherlands
4. Care and Public Health Research Institute, Maastricht University Medical Centre, The Netherlands