[1] Univ Estadual Campinas, Campinas, SP, Brazil
[2] Sao Paulo State STD AIDS Program, Sao Paulo, Brazil
[3] Johns Hopkins Bloomberg Sch Publ Hlth, Baltimore, MD USA
[4] Univ Calif San Francisco, San Francisco, CA 94143 USA
[5] Natl STD AIDS Program, Brasilia, DF, Brazil
[6] UNAIDS, So Cone Off, Buenos Aires, DF, Argentina