1. a Centers for Disease Control and Prevention (CDC), Division of HIV/AIDS Prevention , Mailstop E-30, 1600 Clifton Road, Atlanta , GA , 30333 , USA
2. b ICF Macro , 3 Corporate Square NE , Suite 370, Atlanta , GA , 30329 , USA
3. c Kenyatta National Hospital/University of Nairobi , P.O. Box 20723, Nairobi , Kenya
4. d Centre for Infectious Disease Research in Zambia (CIDRZ) , P.O. Box 34681, Lusaka , Zambia
5. e CDC–Kenya, Kenya Medical Research Institute , P.O. Box 30137, Mbagathi Road, Nairobi , Kenya
6. f CDC–Zambia , Lusaka , Zambia
7. g Global AIDS Program , NCHHSTP, CDC , Atlanta , GA , USA