1. Department of Global Health, University of Washington, Seattle, Washington.
2. Department of Nursing, University of Washington, Seattle, Washington.
3. College of Health Sciences, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya.
4. Center for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya.
5. Department of Medicine, University of Washington, Seattle, Washington.
6. Department of Epidemiology, University of Washington, Seattle, Washington.