1. Department of Epidemiology of Microbial Diseases, Yale University School of Public Health, New Haven, Connecticut.
2. Department of Biostatistics, Yale University School of Public Health, New Haven, Connecticut.
3. Independent Contractor, Beirut, Lebanon.
4. Department of Chronic Disease Epidemiology, Yale University School of Public Health, New Haven, Connecticut.
5. Middle East and North Africa Harm Reduction Association, Sin-el-Fil, Lebanon.