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