1. Department of Infectious Disease, School of Medicine , Alborz University of Medical Sciences , Karaj , Iran
2. Department of Anesthesiology and Critical Care, School of Medicine , Hamadan University of Medical Sciences , Hamadan , Iran
3. Department of Community Medicine, School of Medicine , Hamadan University of Medical Sciences , Hamadan , Iran
4. Student Research Committee , Hamadan University of Medical Sciences , Hamadan , Iran