1. a Hubert Department of Global Health, Rollins School of Public Health , Emory University , Atlanta , US
2. b Rwanda–Zambia Emory HIV Research Group, Rollins School of Public Health , Emory University , Atlanta , US
3. c Department of Internal Medicine, School of Medicine , Stanford University , San Jose , California , US
4. d Department of Epidemiology, School of Public Health , University of Alabama Birmingham , US
5. e Department of Medicine, University Teaching Hospital School of Medicine , University of Zambia , Lusaka , Zambia
6. f District Health Management Team , Lusaka , Zambia
7. g Department of Pediatrics, University Teaching Hospital School of Medicine , University of Zambia , Lusaka , Zambia