1. Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor
2. Centro Nacional de Diagnóstico y Referencia, Ministry of Health, Managua, Nicaragua
3. Sustainable Sciences Institute, Managua, Nicaragua
4. Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley
5. Centro de Salud Sócrates Flores Vivas, Ministry of Health, Managua, Nicaragua