1. Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
2. Department of Pediatrics and Adolescent Medicine, Turku University Hospital, Turku
3. Department of Pediatrics and Adolescent Medicine, University of Turku, Turku
4. Department of Clinical Microbiology, Turku University Hospital, Turku
5. Expert Microbiology Unit, National Institute for Health and Welfare, Helsinki, Finland
6. Infectious Disease Control and Vaccinations Unit, National Institute for Health and Welfare, Helsinki, Finland
7. Department of Medical Microbiology and Immunology, University of Turku, Turku