1. School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
2. Department of Epidemiology, University of Washington, Seattle, WA, USA
3. Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA
4. Department of Global Health, University of Washington, Seattle, WA, USA
5. Department of Medicine, University of Washington, Seattle, WA, USA
6. Centre for Public Health Research, Kenya Medical Research Institute, Nairobi, Kenya
7. School of Public Health, Kenyatta University, Nairobi, Kenya
8. Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
9. Department of Obstetrics and Gynecology, University of Nairobi, Nairobi, Kenya
10. Department of Paediatrics and Child Health, University of Nairobi, Nairobi, Kenya