[1] Univ Calif Los Angeles, David Geffen Sch Med, Dept Med, Div Infect Dis, Los Angeles, CA 90095 USA
[2] Univ Peruana Cayetano Heredia, Sch Publ Hlth, Unit Epidemiol STD & HIV, Lima, Peru
[3] Inst Nacl Materno Perinatal, Lima, Peru
[4] Hosp Nacl Arzobispo Loayza, Lima, Peru
[5] Univ Washington, Dept Global Hlth, Seattle, WA 98195 USA
[6] Univ Mayor San Marcos, Inst Med Trop, Lima, Peru