title: Neurologic complications of influenza A(H1N1)pdm09: surveillance in 6 pediatric hospitals.
abstract: OBJECTIVE
  We sought to determine the range and extent of neurologic complications due to pandemic influenza A (H1N1) 2009 infection (pH1N1'09) in children hospitalized with influenza.
  
  
  METHODS
  Active hospital-based surveillance in 6 Australian tertiary pediatric referral centers between June 1 and September 30, 2009, for children aged <15 years with laboratory-confirmed pH1N1'09.
  
  
  RESULTS
  A total of 506 children with pH1N1'09 were hospitalized, of whom 49 (9.7%) had neurologic complications; median age 4.8 years (range 0.5-12.6 years) compared with 3.7 years (0.01-14.9 years) in those without complications. Approximately one-half (55.1%) of the children with neurologic complications had preexisting medical conditions, and 42.8% had preexisting neurologic conditions. On presentation, only 36.7% had the triad of cough, fever, and coryza/runny nose, whereas 38.7% had only 1 or no respiratory symptoms. Seizure was the most common neurologic complication (7.5%). Others included encephalitis/encephalopathy (1.4%), confusion/disorientation (1.0%), loss of consciousness (1.0%), and paralysis/Guillain-Barré syndrome (0.4%). A total of 30.6% needed intensive care unit (ICU) admission, 24.5% required mechanical ventilation, and 2 (4.1%) died. The mean length of stay in hospital was 6.5 days (median 3 days) and mean ICU stay was 4.4 days (median 1.5 days).
  
  
  CONCLUSIONS
  Neurologic complications are relatively common among children admitted with influenza, and can be life-threatening. The lack of specific treatment for influenza-related neurologic complications underlines the importance of early diagnosis, use of antivirals, and universal influenza vaccination in children. Clinicians should consider influenza in children with neurologic symptoms even with a paucity of respiratory symptoms.
authors.affiliation: National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, Sydney, Australia.
authors.forename: Gulam
authors.initials: G
authors.lastname: Khandaker
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Zurynski
authors.forename: Jim
authors.initials: J
authors.lastname: Buttery
authors.forename: Helen
authors.initials: H
authors.lastname: Marshall
authors.forename: Peter C
authors.initials: PC
authors.lastname: Richmond
authors.forename: Russell C
authors.initials: RC
authors.lastname: Dale
authors.forename: Jenny
authors.initials: J
authors.lastname: Royle
authors.forename: Michael
authors.initials: M
authors.lastname: Gold
authors.forename: Tom
authors.initials: T
authors.lastname: Snelling
authors.forename: Bruce
authors.initials: B
authors.lastname: Whitehead
authors.forename: Cheryl
authors.initials: C
authors.lastname: Jones
authors.forename: Leon
authors.initials: L
authors.lastname: Heron
authors.forename: Mary
authors.initials: M
authors.lastname: McCaskill
authors.forename: Kristine
authors.initials: K
authors.lastname: Macartney
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Elliott
authors.forename: Robert
authors.initials: R
authors.lastname: Booy
mesh_terms: D000293:Adolescent; D016009:Chi-Square Distribution; D002648:Child; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000472:pathogenicity*; D007251:Influenza, Human / Q000150:complications*; D007362:Intensive Care Units; D009422:Nervous System Diseases / Q000209:etiology* / Q000821:virology*