1. 1Kenyatta National Hospital, Nairobi, Kenya
2. 2Department of Global Health, University of Washington, Seattle, WA, USA
3. 3Department of Epidemiology, University of Washington, Seattle, WA, USA
4. 4Department of Medicine, University of Washington, Seattle, WA, USA
5. 5Department of Pediatrics, University of Washington, Seattle, WA, USA