1. Departments of Medicine and Epidemiology, University of California, Los Angeles, Los Angeles, California, USA
2. Department of Medicine, University of California, San Diego, La Jolla, California, USA
3. Neisseria Reference Laboratory, University of Washington, Seattle, Washington, USA
4. Social Scientific Systems, Silver Spring, Maryland, USA
5. Los Angeles LGBT Center, Los Angeles, California, USA
6. San Francisco Department of Public Health, San Francisco, California, USA
7. Philadelphia Department of Public Health, Philadelphia, Pennsylvania, USA
8. Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
9. University of Mississippi Medical Center, Oxford, Mississippi, USA
10. Whitman Walker Health, Washington, D.C., USA
11. The Emmes Company, Rockville, Maryland, USA