title: Incidence and predisposing factors for severe disease in previously healthy term infants experiencing their first episode of bronchiolitis.
abstract: OBJECTIVE
  To determine the incidence and predisposing factors for severe bronchiolitis in previously healthy term infants <12 months of age experiencing their first episode of bronchiolitis.
  
  
  METHODS
  Epidemiological, clinical and virological data were prospectively collected. Severity was assessed by the need for ventilatory support.
  
  
  RESULTS
  Of the 310 infants enrolled, 16 (5.1%) presented with severe bronchiolitis requiring ventilatory support (11 since admission). Compared with infants with less severe bronchiolitis, infants with severe disease presented with lower birth weight, gestational age, postnatal weight and postnatal age, and were more likely to be born by cesarian section. C-reactive protein positive results (>0.8 mg/dL) and pulmonary consolidation on chest X-ray were more common among infants with severe disease. Severity was independently associated with younger age on admission <30 days, respiratory syncytial virus (RSV) infection and lymphocyte counts < 3200/μL. No significant differences were found between epidemiologic variables.
  
  
  CONCLUSIONS
  Severe bronchiolitis is uncommon in previously healthy term infants <12 months of age and when present develops soon after disease onset. Severity is predicted by young age and RSV carriage, whereas epidemiologic variables seem less likely to intervene.
authors.affiliation: Pediatric Emergency and Intensive Care, Department of Pediatrics, Sapienza University of Rome, Rome, Italy. p.papoff@libero.it
authors.forename: Paola
authors.initials: P
authors.lastname: Papoff
authors.forename: Corrado
authors.initials: C
authors.lastname: Moretti
authors.forename: Giulia
authors.initials: G
authors.lastname: Cangiano
authors.forename: Enea
authors.initials: E
authors.lastname: Bonci
authors.forename: Mario
authors.initials: M
authors.lastname: Roggini
authors.forename: Alessandra
authors.initials: A
authors.lastname: Pierangeli
authors.forename: Carolina
authors.initials: C
authors.lastname: Scagnolari
authors.forename: Guido
authors.initials: G
authors.lastname: Antonelli
authors.forename: Fabio
authors.initials: F
authors.lastname: Midulla
mesh_terms: D017677:Age Distribution; D001988:Bronchiolitis / Q000453:epidemiology* / Q000628:therapy / Q000821:virology*; D005260:Female; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D018655:Lymphocyte Count; D008297:Male; D011446:Prospective Studies; D012121:Respiration, Artificial; D012307:Risk Factors; D012720:Severity of Illness Index; D047929:Term Birth