1. Department of Pediatrics and Adolescent Medicine, Oulu University Hospital , Oulu , Finland
2. Research Unit of Clinical Medicine and Medical Research Center Oulu, University of Oulu , Oulu , Finland
3. Clinical Microbiology Laboratory, Nordlab, Oulu , Finland
4. Department of Pediatrics and Adolescent Medicine, Turku University Hospital and University of Turku , Turku , Finland
5. Institute of Biomedicine, University of Turku , Turku , Finland
6. Research Service Unit, Oulu University Hospital , Oulu , Finland
7. Biocenter Oulu, University of Oulu , Oulu , Finland