1. Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado;
2. Fundacion para la Salud Integral de los Guatemaltecos, Retalhuleu, Guatemala;
3. Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Nevada;
4. Colorado School of Public Health, Aurora, Colorado;
5. Centro de Estudios en Salud, Universidad del Valle de Guatemala, Guatemala City, Guatemala;
6. Center for Human Development, Retalhuleu, Guatemala;
7. Department of Pediatrics, Section of Infectious Diseases, University of Colorado School of Medicine, Aurora, Colorado