1. Faculty of Medicine; Division of Pediatrics; Department of Pediatric Gastroenterology and Nutrition; Pontificia Universidad Católica de Chile; Santiago Chile
2. Hospital Regional Leonardo Guzmán; Antofagasta Chile
3. Faculty of Medicine; Departament of Gastroenterology; Pontificia Universidad Católica de Chile; Santiago Chile
4. Faculty of Medicine; Division of Pediatrics; Department of Pediatric Gastroenterology and Nutrition; Laboratory of Gastrointestinal Infections and Immunology; Pontificia Universidad Católica de Chile; Santiago Chile