1. Section of Infectious Diseases, Boston Medical Center, Boston, MA
2. Department of Psychology, University of Maryland, College Park, MD
3. Department of Biostatistics, Boston University, Boston, MA
4. Section of General Internal Medicine, Boston Medical Center, Boston, MA, USA
5. Alcohol, Tobacco and Other Drug Research Unit, South African Medical Research Council, Cape Town, Department of Psychiatry, Stellenbosch University, Cape Town, South Africa
6. Section of Infectious Diseases, Boston Medical Center, Boston, MA, Department of Biostatistics, Boston University, Boston, MA, Department of Global Health, Department of Epidemiology, Boston University, Boston, MA, USA
7. Alcohol, Tobacco and Other Drug Research Unit, South African Medical Research Council, Cape Town, Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa