1. Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
2. Harvard T. H. Chan School of Public Health, Boston, Massachusetts
3. TASK Applied Science and Stellenbosch University, Cape Town, South Africa
4. Division of AIDS, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland
5. Frontier Science and Technology Research Foundation, Amherst, New York
6. Social & Scientific Systems, Inc., Silver Spring, Maryland; and
7. Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska