1. Center for Emerging and Reemerging Infectious Diseases, University of Washington , Seattle, Washington , USA
2. Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington , Seattle, Washington , USA
3. Service des Maladies Infectieuses et Tropicales, Centre Hospitalier National Universitaire de Fann , Dakar , Senegal
4. Department of Global Health, University of Washington , Seattle, Washington , USA