1. Alpert Medical School of Brown University, Providence, Rhode Island, USA
2. Center for Public Health Research, Kenya Medical Research Institute, Nairobi, Kenya
3. Department of Global Health
4. Department of Epidemiology
5. Medicine, University of Washington, Seattle, Washington, USA
6. University of Nairobi College of Health Sciences, Institute of Tropical and Infectious Diseases, Partners for Health and Development in Africa, Nairobi, Kenya
7. Department of Emergency Medicine, Alpert Medical School of Brown University, Providence, Rhode Island, USA.