1 Pediatric Respiratory and Allergy Unit, Dr. Balmis General University Hospital, Alicante Institute for Health and Biomedical Research, Alicante, Spain.
2 Pediatric Intensive Care Unit, Virgen de la Arrixaca Clinical University Hospital, Murcia, Spain.
3 Pediatric Infectious Diseases Unit, Virgen de la Arrixaca Clinical University Hospital, Murcia, Spain.