[1] Johns Hopkins Bloomberg Sch Publ Hlth, Baltimore, MD USA
[2] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Populat Family & Reprod Hlth, Baltimore, MD USA
[3] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Biostat, Baltimore, MD USA
[4] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Epidemiol, Baltimore, MD USA
[5] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Int Hlth, Baltimore, MD USA
[6] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Populat Family & Reprod Hlth, Baltimore, MD USA
[7] Uganda Virus Res Inst, Rakai Hlth Sci Program, Entebbe, Uganda
[8] Makerere Univ, Sch Publ Hlth, Kampala, Uganda