The field sites where patients will be recruited for screening and enrollment are in Kenya. All of these sites are currently receiving support through CDC Kenya using the PEPFAR mechanism. Laboratory procedures will be performed at each clinic site, in Nairobi and in Seattle, Washington. The study will be reviewed by the Institutional Review Board (IRB) at the University of Washington and the Ethical Review Board (ERC) at the Kenya Medical Research Institute (KEMRI). The study will not recruit subjects prior to approval from both the University of Washington IRB and the KEMRI ERC.