title: Characterization of 2009 H1N1 pandemic influenza in a population of Dutch children with influenza-like signs and symptoms.
abstract: OBJECTIVE
  To determine causative respiratory pathogens and describe epidemiological and clinical characteristics in a paediatric population with influenza-like illness during the 2009 H1N1-pandemic.
  
  
  METHODS
  Observational study of 412 children visiting an outpatient clinic of a Dutch teaching hospital.
  
  
  RESULTS
  From August to December 2009, 412 children were tested at the clinic; 32% proved H1N1-positive, confirmed by reverse-transcriptase-polymerase-chain-reaction (RT-PCR). Pathogens were detected in 65% of samples. Influenza A(H1N1) (n = 132), human rhinovirus (n = 55), respiratory syncytial virus (n = 45) and adenovirus (n = 34) were mostly identified. Co-infections were seen in 34 children (8.3%). Mean age was 6.8 and 4.2 years in H1N1-positive and H1N1-negative cases, respectively (p < 0.01). H1N1-positive outpatient children reported fever, cough and rhinorrhoea more frequently than their H1N1-negative counterparts. Of 72 hospitalized children, 31% proved H1N1-positive; all showed a relatively mild clinical illness. None of the children had been admitted to an intensive care unit or died. Oseltamivir treatment was initiated in 72 children and discontinued in 42 (63%) when RT-PCR results turned negative.
  
  
  CONCLUSIONS
  The 2009 H1N1-pandemic showed a mild clinical course in a Dutch paediatric outpatient clinic population. Respiratory pathogens were detected in the majority of children with influenza-like illness and influenza A(H1N1) virus was identified in one-third. Testing symptomatic children during an influenza pandemic has effectively limited the use of oseltamivir.
authors.affiliation: Department of Internal Medicine, Slotervaart Hospital, Amsterdam, The Netherlands. patrickmsmit@gmail.com
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Smit
authors.forename: Karlien M
authors.initials: KM
authors.lastname: Bongers
authors.forename: Rosalie J L
authors.initials: RJ
authors.lastname: Kuiper
authors.forename: Ines A
authors.initials: IA
authors.lastname: von Rosenstiel
authors.forename: Paul H M
authors.initials: PH
authors.lastname: Smits
authors.forename: Dees P M
authors.initials: DP
authors.lastname: Brandjes
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000188:drug therapy / Q000453:epidemiology / Q000821:virology*; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D053139:Oseltamivir / Q000627:therapeutic use; D058873:Pandemics; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000998:Antiviral Agents; D053139:Oseltamivir