1. Pediatric Infectious Diseases Unit, Gregorio Marañón Hospital, Madrid, Spain
2. Department of Infectious Diseases and Tropical Pediatrics, La Paz Hospital, Madrid, Spain
3. Pediatric Infectious Diseases Unit, Gregorio Marañón Hospital, Complutense University, Madrid, Spain
4. Department of Infectious Diseases and Clinical Microbiology, Gregorio Marañón Hospital, Complutense University, Madrid, Spain