1 Paediatric Intensive Care Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain.
2 Immunological and Respiratory Disorders in the Paediatric Critical Patient Research Group, Institut de Recerca Hospital Sant Joan de Déu, Hospital Sant Joan de Déu, Barcelona, Spain.
3 Paediatric Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain.
4 Infections Control Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain.
5 Pediatric Infectious Diseases Research Group, CIBERESP, Institut de Recerca Sant Joan de Deu, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain.