1. Juvenile Diabetes Foundation International Center for the Prevention of type 1 diabetes in Finland and the Department of Virology, University of Tampere, Medical School, Tampere, Finland
2. National Public Health Institute, Helsinki, Finland
3. National Public Health Institute, Oulu, Finland
4. Department of Public Health, University of Helsinki, Helsinki, Finland
5. Department of Clinical Microbiology, Centre for Laboratory Medicine, Tampere University Hospital, Tampere, Finland