1. Infectious Diseases Division, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Av. México-Xochimilico #289 Col, Arenal de Guadalupe, Alc. Tlalpan, Mexico City, Mexico
2. Unit of Hospital Epidemiology Surveillance, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Av. México-Xochimilico #289 Col, Arenal de Guadalupe, Alc. Tlalpan, Mexico City, Mexico