title: Procalcitonin for clinical decisions on influenza-like illness in emergency department during influenza a(H1N1)2009 pandemic.
abstract: OBJECTIVE
  We aimed to determine whether serum procalcitonin (PCT) values could help in identifying flu in patient admitted to the emergency department (ED) with influenza-like illness (ILI) during influenza A(H1N1)2009 pandemic.
  
  
  METHODS
  An observational retrospective cohort study was performed in a referral ED for emerging infectious diseases. All patients tested for influenza A(H1N1)2009 by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and procalcitonin between June 2009 and January 2010 were analyzed. PCT was studied for its negative predictive value of bacterial infection. Patients PCT-/RT-PCR + were considered as true positive.
  
  
  RESULTS
  On the 80 patients included, 16 were positive for influenza A(H1N1)2009 RT-PCR, all but one of them had low PCT concentrations. Conversely, 19 (30%) of the 64 patients with negative RT-PCR had elevated PCT concentrations. For a PCT threshold <0.25 μg/L, sensitivity was 0.94, specificity 0.30, positive predictive value 0.25 and negative predictive value 0.95 for the diagnosis of flu.
  
  
  CONCLUSIONS
  In the context of an influenza pandemic, serum PCT measurement may be useful for clinical decisions in the ED as most of RT-PCR confirmed patients have low PCT values. Patients with PCT above 0.25 μg/L are unlikely to have a unique diagnosis of flu.
authors.affiliation: a Department of Emergency , Pitié-Salpêtrière University Hospital, Assistance Publique-Hôpitaux de Paris (APHP) , Paris , France.
authors.forename: P
authors.initials: P
authors.lastname: Canavaggio
authors.affiliation: b Virology Laboratory , Pitié-Salpêtrière University Hospital, Assistance Publique-Hôpitaux de Paris (APHP) , Paris , France.|c Sorbonne Universités UPMC-Univ Paris06, INSERM U1135, CIMI , Paris , France.
authors.forename: D
authors.initials: D
authors.lastname: Boutolleau
authors.affiliation: a Department of Emergency , Pitié-Salpêtrière University Hospital, Assistance Publique-Hôpitaux de Paris (APHP) , Paris , France.
authors.forename: H
authors.initials: H
authors.lastname: Goulet
authors.affiliation: a Department of Emergency , Pitié-Salpêtrière University Hospital, Assistance Publique-Hôpitaux de Paris (APHP) , Paris , France.|d Sorbonne Universités UPMC-Univ Paris06, GRC-14 BIOSFAST, UMRS INSERM 1166 , Paris , France.
authors.forename: B
authors.initials: B
authors.lastname: Riou
authors.affiliation: a Department of Emergency , Pitié-Salpêtrière University Hospital, Assistance Publique-Hôpitaux de Paris (APHP) , Paris , France.|d Sorbonne Universités UPMC-Univ Paris06, GRC-14 BIOSFAST, UMRS INSERM 1166 , Paris , France.
authors.forename: P
authors.initials: P
authors.lastname: Hausfater
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002116:Calcitonin / Q000097:blood*; D004636:Emergency Service, Hospital; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics* / Q000502:physiology; D007251:Influenza, Human / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D058873:Pandemics; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D002116:Calcitonin
keywords: Procalcitonin; antibiotic; emergency department; flu; influenza