1. HIV/STI Surveillance Research Center, and WHO Collaborating Center for HIV Surveillance, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran
2. Clinical Research Development Center, Amiralmomenin Hospital, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
3. Iran University of Medical Sciences, Tehran, Iran
4. Iranian Research Center for HIV/AIDS, Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran
5. HIV/AIDS Control Office, Center for Communicable Disease, Ministry of Health, Tehran, Iran
6. Department of Epidemiology, School of Public Health and Research Center for Health Sciences, Hamadan university of Medical Sciences, Hamadan, Iran
7. Iran Blood Transfusion, Tehran, Iran
8. Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA