1. Department of Medicine, University of California, San Diego, California, USA.
2. Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom.
3. Department of Psychiatry and Behavioral Sciences, Northwestern University, Chicago, Illinois, USA.
4. Third Coast Center for AIDS Research, Northwestern University, Chicago, Illinois, USA.
5. Division of HIV and STD Programs, Los Angeles County Department of Public Health, Los Angeles, California, USA.
6. HIV/AIDS Section, Illinois Department of Public Health, Chicago, Illinois, USA.
7. HIV Epidemiology and Field Services Program, Bureau of HIV Prevention and Control, New York City Department of Health and Mental Hygiene, New York City, New York, USA.