[1] Brown Univ, Providence, RI 02912 USA
[2] Miriam Hosp, Providence, RI 02912 USA
[3] NIH, Bethesda, MD 20892 USA
[4] Blue Cross Blue Shield Assoc, San Francisco, CA USA
[5] Womens Informat Serv & Exchange, Atlanta, GA USA
[6] Tufts Univ, Sch Med, Boston, MA 02111 USA
[7] Natl Ctr HIV Epidemiol & Clin Res, Sydney, NSW, Australia
[8] Davies Med Ctr, San Francisco, CA USA
[9] New York City Dept Hlth, New York, NY 10013 USA
[10] Treatment Act Grp, New York, NY USA
[11] Ctr AIDS Serv Planning & Dev, Baltimore, MD USA
[12] Ctr Dis Control & Prevent, Atlanta, GA USA
[13] Magee Womens Hosp, Pittsburgh, PA USA
[14] Childrens Hosp, Boston, MA 02115 USA
[15] Harvard Univ, Sch Med, Boston, MA 02115 USA
[16] Univ Calif San Diego, La Jolla, CA 92093 USA
[17] Univ Alabama Birmingham, Birmingham, AL USA
[18] Univ Colorado, Hlth Sci Ctr, Denver, CO USA
[19] Brown Univ, Sch Med, Providence, RI 02912 USA
[20] AIDS Res Consortium Atlanta, Atlanta, GA USA
[21] Salk Inst Biol Studies, La Jolla, CA USA
[22] Ist Super Sanita, Virol Lab, I-00161 Rome, Italy
[23] X Bichat Med Sch, Paris, France