Volume 68, no. 3, p. 176-180, 2015. Page 176, affiliation "(1) Foodborne and Waterborne Diseases Research Center, Tehran; (2)Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Tehran; (3)Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran; and (4)Gastroenterology and Liver Diseases Research center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran" should read "(1) Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran; (2)Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran; (3)Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran; and (4)Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran".