1 Infectious Diseases Unit, Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
2 Infectious Diseases Unit, Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain, Universidad Complutense de Madrid, Madrid, Spain.
3 Infectious Diseases Unit, Department of Pediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.