1. Centre for Infectious Disease Control; National Institute for Public Health and the Environment; Bilthoven The Netherlands
2. Department for Statistics; Informatics and Modeling; National Institute for Public Health and the Environment; Bilthoven The Netherlands
3. NIVEL Primary Care Database; Sentinel Practices; Utrecht The Netherlands
4. Department of Medical Microbiology; Academic Medical Center; Center for Infection and Immunity Amsterdam; Amsterdam The Netherlands
5. Netherlands Reference Laboratory for Bacterial Meningitis; Amsterdam The Netherlands