1. Department of Epidemiology and Center for Global Health, Colorado School of Public Health, Aurora, Colorado;
2. Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York;
3. Center for Human Development, Fundacion para la Salud Integral de los Guatemaltecos, FUNSALUD, Coatepeque, Quetzaltenango, Guatemala;
4. Emory University Department of Medicine, Division of Infectious Diseases, Atlanta, Georgia;
5. Centro de Estudios en Salud, Universidad del Valle de Guatemala, Guatemala City, Guatemala;
6. Sanofi, Swiftwater, Pennsylvania;
7. Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado