1 Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD, USA. [email protected].
2 Center for Global Health and Development, Boston University School of Public Health, Boston University, Boston, MA, USA.
3 Department of Emergency Medicine, University of New Mexico School of Medicine, Albuquerque, NM, USA.
4 Department of Paediatrics, University of Zambia, School of Medicine, Lusaka, Zambia.
5 Zambia Center for Applied Health Research and Development, Lusaka, Zambia.
6 University of Missouri School of Medicine, Columbia Missouri, MO, USA.
7 Bill & Melinda Gates Foundation, Seattle, WA, USA.
8 Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD, USA.