[1] Univ Calif San Francisco, Sch Med, San Francisco, CA USA
[2] David Geffen Sch Med, South Amer Program HIV Prevent Res, Div Infect Dis, Dept Med, Los Angeles, CA USA
[3] APAIT, Special Serv Grp, Los Angeles, CA USA
[4] Dartmouth Coll, Geisel Sch Med, Hanover, NH 03755 USA
[5] Univ Peruana Ciencias Aplicadas, Escuela Med, Lima, Peru
[6] Univ Texas Hlth Sci Ctr Houston, McGovern Med Sch, Dept Internal Med, Div Infect Dis, Houston, TX 77030 USA