title: Evaluation of the Cepheid Xpert Flu Assay for rapid identification and differentiation of influenza A, influenza A 2009 H1N1, and influenza B viruses.
abstract: The Xpert Flu Assay cartridge is a next-generation nucleic acid amplification system that provides multiplexed PCR detection of the influenza A, influenza A 2009 H1N1, and influenza B viruses in approximately 70 min with minimal hands-on time. Six laboratories participated in a clinical trial comparing the results of the new Cepheid Xpert Flu Assay to those of culture or real-time PCR with archived and prospectively collected nasal aspirate-wash (NA-W) specimens and nasopharyngeal (NP) swabs from children and adults. Discrepant results were resolved by DNA sequence analysis. After discrepant-result analysis, the sensitivities of the Xpert Flu Assay for prospective NA-W specimens containing the influenza A, influenza A 2009 H1N1, and influenza B viruses compared to those of culture were 90.0%, 100%, and 100%, respectively, while the sensitivities of the assay for prospective NP swabs compared to those of culture were 100%, 100%, and 100%, respectively. The sensitivities of the Xpert Flu Assay for archived NA-W specimens compared to those of Gen-Probe ProFlu+ PCR for the influenza A, influenza A 2009 H1N1, and influenza B viruses were 99.4%, 98.4%, and 100%, respectively, while the sensitivities of the Xpert Flu Assay for archived NP swabs compared to those of ProFlu+ were 98.1%, 100%, and 93.8%, respectively. The sensitivities of the Xpert Flu Assay with archived NP specimens compared to those of culture for the three targets were 97.5%, 100%, and 93.8%, respectively. We conclude that the Cepheid Xpert Flu Assay is an accurate and rapid method that is suitable for on-demand testing for influenza viral infection.
authors.affiliation: Southern California Permanente Medical Group, North Hollywood, California, USA. Susan.M.Novak@kp.org
authors.forename: S M
authors.initials: SM
authors.lastname: Novak-Weekley
authors.forename: E M
authors.initials: EM
authors.lastname: Marlowe
authors.forename: M
authors.initials: M
authors.lastname: Poulter
authors.forename: D
authors.initials: D
authors.lastname: Dwyer
authors.forename: D
authors.initials: D
authors.lastname: Speers
authors.forename: W
authors.initials: W
authors.lastname: Rawlinson
authors.forename: C
authors.initials: C
authors.lastname: Baleriola
authors.forename: C C
authors.initials: CC
authors.lastname: Robinson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009980:Influenza A virus / Q000145:classification* / Q000302:isolation & purification*; D009981:Influenza B virus / Q000145:classification* / Q000302:isolation & purification*; D007251:Influenza, Human / Q000821:virology*; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods; D009296:Nasal Cavity / Q000821:virology; D012680:Sensitivity and Specificity; D013997:Time Factors; D014773:Virology / Q000379:methods*; D055815:Young Adult