1. MPH department Shiraz University of Medical Sciences Shiraz Iran
2. Liver and Pancreatobiliary Diseases Research Center, Digestive Diseases Research Institute Tehran University of Medical Sciences Tehran Iran
3. Hearing Research Center, Department of Biostatistics and Epidemiology, School of public health Ahvaz Jundishapur University of Medical Sciences Ahvaz Iran
4. Faculty of Medicine Behbahan Faculty of Medical Sciences Behbahan Iran
5. Faculty of Medicine Shoshtar Faculty of Medical Sciences Shoshtar Iran
6. Department of Clinical Immunology and Allergy Ahvaz Jundishapur University of Medical Sciences Ahvaz Iran
7. School of Medicine Abadan University of Medical Sciences Abadan Iran
8. School of Medicine Dezful University of Medical Sciences Dezful Iran
9. Alimentary Tract Research Center, Clinical Sciences Research Institute, Department of Biostatistics and Epidemiology, School of Public Health Ahvaz Jundishapur University of Medical Sciences Ahvaz Iran
10. Alimentary Tract Research Center, Clinical Sciences Research Institute Ahvaz Jundishapur University of Medical Sciences Ahvaz Iran