1. School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania.
2. University of Oxford, Oxford, England.
3. AIDS Activities Coordinating Office, Philadelphia Department of Public Health, Philadelphia, Pennsylvania.
4. Division of Infectious Diseases, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
5. Perelman School of Medicine, University of Pennsylvania, and Adolescent HIV Services, Craig Dalsimer Division of Adolescent Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.