1. Gastrounit,Medical Division, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark
2. Department of Pediatrics and Adolescent Medicine, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark
3. Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
4. Department of Science and Environment, Roskilde University, Roskilde, Denmark
5. Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
6. Department of Clinical Microbiology, Copenhagen University Hospital Amager and Hvidovre, Copenhagen, Denmark