1. School of Public Health, College of Health Sciences, Addis Ababa University , Addis Ababa , Ethiopia
2. Program in Public Health, College of Health Sciences, University of California at Irvine , Irvine, CA 92697 , USA
3. School of Medicine, College of Health Sciences, Addis Ababa University , Addis Ababa , Ethiopia
4. Eck Institute for Global Health, Department of Biological Sciences, 319 Galvin Life Sciences, University of Notre Dame , South Bend, IN 46556 , USA