1 Department of Pediatrics, Hospital Universitario Fundación de Alcorcón, Alcorcón, Madrid, Spain.
2 PhD Program in Medicine, Universidad Complutense de Madrid, Madrid, Spain.
3 Pediatric Infectious Diseases Unit, Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.
4 Centro de Investigación Biomedica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain.
5 Pediatric Infectious Diseases Unit, Department of Pediatrics, Hospital Universitari Son Espases, Palma de Mallorca, Spain.
6 Pediatrics, Infectious and Tropical Diseases Department, Hospital Universitario La Paz, Instituto Investigación Hospital La Paz (IDIPaz), Madrid, Spain.