1. Department of Paediatric and Adolescent medicine; University Hospital of North Norway; Tromsø Norway
2. Paediatric Research Group; Department of Clinical Medicine; UiT, The Arctic University of Norway; Tromsø Norway
3. Institute of Environmental Medicine; Karolinska Institutet; Stockholm Sweden
4. Sachs' Children's Hospital; Stockholm Sweden
5. Research Group for Host-Microbe Interactions; Department of Medical Biology; Faculty of Health Sciences; UiT, The Arctic University of Norway; Tromsø Norway
6. Department of Microbiology and Infection Control; University Hospital of North Norway; Tromsø Norway
7. Epidemiology of Chronic Diseases Research Group; Department of Community Medicine; Faculty of Health Sciences; UiT, The Arctic University of Norway; Tromsø Norway