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