title: Necessity to critically review the automatic results of the Xpert Flu assay.
abstract: While using the Xpert Flu assay we became aware of false-negative results. The study aimed to analyze the causes of these false-negative results. One hundred fifty-nine respiratory specimens were tested in the Xpert Flu assay and in multiplex reverse transcription-polymerase chain reactions (RT-PCRs) for respiratory viruses. Discordant specimens were tested in the Influenza A/B r-gene assay. One hundred fifty-two (96%) and 151 (95%) specimens yielded concordant results for influenza A and B, respectively. Fifteen specimens tested negative in the Xpert Flu assay and positive in a multiplex RT-PCR. Positive results were confirmed for 12 of these specimens in the Influenza A/B r-gene assay. Xpert Flu assay amplification curves and endpoints suggested that the false-negative results were mainly due to erroneous automatic result interpretation. We report false-negative results of the Xpert Flu assay due to erroneous automatic result interpretation. Careful analysis of amplification curves and endpoints is needed to avoid reporting of false-negative results.
authors.affiliation: Univ Lille, Faculté de Médecine, CHU Lille, Laboratoire de Virologie EA3610, F-59000 Lille, France. Electronic address: ilka.engelmann@chru-lille.fr.
authors.forename: Ilka
authors.initials: I
authors.lastname: Engelmann
authors.affiliation: Univ Lille, Faculté de Médecine, CHU Lille, Laboratoire de Virologie EA3610, F-59000 Lille, France.
authors.forename: Enagnon Kazali
authors.initials: EK
authors.lastname: Alidjinou
authors.affiliation: Univ Lille, Faculté de Médecine, CHU Lille, Laboratoire de Virologie EA3610, F-59000 Lille, France.
authors.forename: Mouna
authors.initials: M
authors.lastname: Lazrek
authors.affiliation: Univ Lille, Faculté de Médecine, CHU Lille, Laboratoire de Virologie EA3610, F-59000 Lille, France.
authors.forename: Anny
authors.initials: A
authors.lastname: Dewilde
authors.affiliation: Univ Lille, Faculté de Médecine, CHU Lille, Laboratoire de Virologie EA3610, F-59000 Lille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Hober
mesh_terms: D057205:Automation, Laboratory / Q000379:methods*; D005188:False Negative Reactions; D006801:Humans; D007251:Influenza, Human / Q000175:diagnosis*; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D019095:Point-of-Care Systems
keywords: Discordance; Flu; Influenza; Molecular diagnostic techniques; PCR; Point-of-care