1. Department of Pediatrics, Stavanger University Hospital, Stavanger, Norway
2. Department of Medical Microbiology, Hospital of Southern Norway Trust, Kristiansand, Norway
3. Department of Pediatrics, Hospital of Southern Norway Trust, Kristiansand, Norway
4. Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
5. Department of Pediatrics, Haugesund Hospital, Haugesund, Norway
6. Department of Pediatrics, Hospital of Southern Norway Trust, Arendal, Norway
7. Department of Clinical Science, University of Bergen, Bergen, Norway