title: Novel influenza A (H1N1): clinical features of pediatric hospitalizations in two successive waves.
abstract: OBJECTIVE
  To describe and compare the characteristics of children hospitalized with novel influenza A (H1N1) during two successive waves.
  
  
  METHODS
  This was a medical chart review of all children hospitalized in a French Canadian pediatric hospital in Montreal in the spring and fall of 2009 with a positive real-time polymerase chain reaction for novel influenza A (H1N1) and flu-like symptoms.
  
  
  RESULTS
  We included 202 children with a median age of 4.9 (range 0.1-18) years. Demographic and clinical features of the children in the two waves were similar. One or more underlying medical conditions were found in 59% of the children. Clinical findings at admission were: fever (98%), cough (88%), congestion/rhinorrhea (58%), gastrointestinal symptoms (47%), oxygen saturation below 95% (33%), sore throat (20%), and neurological symptoms (9%). Admission to the intensive care unit was required for 22 (11%) children, and 14 patients needed respiratory support. During the second wave, the median duration of stay was shorter (3 vs. 4 days, p=0.003) and oseltamivir was used more often (84% vs. 40%, p<0.001).
  
  
  CONCLUSIONS
  Children hospitalized during the two successive waves of H1N1 were mainly school-aged and suffered from moderate disease. Although clinical features and severity of disease were similar, oseltamivir was prescribed more frequently and the length of hospital stay was shorter in the second wave.
authors.affiliation: Infectious Disease Division, Department of Pediatrics, Sainte-Justine Hospital, University of Montreal, 3175 Chemin de cote Sainte-Catherine, H3T 1C5 Montreal, QC, Canada.
authors.forename: Elise
authors.initials: E
authors.lastname: Launay
authors.forename: Philippe
authors.initials: P
authors.lastname: Ovetchkine
authors.forename: Maude
authors.initials: M
authors.lastname: Saint-Jean
authors.forename: Léna
authors.initials: L
authors.lastname: Coïc
authors.forename: Thierry
authors.initials: T
authors.lastname: Ducruet
authors.forename: Hugues
authors.initials: H
authors.lastname: Charest
authors.forename: Nadia
authors.initials: N
authors.lastname: Desmarais
authors.forename: Valérie
authors.initials: V
authors.lastname: Lamarre
authors.forename: Bruce
authors.initials: B
authors.lastname: Tapiéro
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D021821:Communicable Diseases, Emerging / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D003428:Cross Infection / Q000150:complications; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006776:Hospitals, Pediatric / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D015278:Intensive Care Units, Pediatric / Q000706:statistics & numerical data; D008297:Male; D009894:Opportunistic Infections / Q000150:complications; D016133:Polymerase Chain Reaction; D011792:Quebec / Q000453:epidemiology; D012189:Retrospective Studies