title: Quantitative analysis of four rapid antigen assays for detection of pandemic H1N1 2009 compared with seasonal H1N1 and H3N2 influenza A viruses on nasopharyngeal aspirates from patients with influenza.
abstract: Data on analytical sensitivity of rapid diagnostic assays are important for clinical management of influenza, especially during a pandemic. Four rapid antigen detection assays were compared for detection of pandemic influenza A H1N1 2009, seasonal H1N1 and H3N2 in 96 patients with influenza A infection confirmed by real-time RT-PCR. These rapid antigen tests appeared to have lower sensitivity (55.8%) for the diagnosis of pandemic influenza A H1N1 2009 as compared with seasonal H3N2 (71.0%) or H1N1 (69.4%) influenza infections, a difference that was related to a lower viral load in patients infected with the pandemic influenza A H1N1 2009 virus. The detection limit of these antigen detection tests in clinical specimens was an influenza A M gene copy number of average 1.0×10(7) copies/ml. Significant variations between tests in sensitivity for detection of pandemic influenza A H1N1 2009 (43.4-63.3%) were observed. The Directigen EZ Influenza A+B and the Espline Influenza A+B had comparable sensitivity (63%) and were the most sensitive among the four assays evaluated.
authors.affiliation: Department of Microbiology, Queen Mary Hospital, Hong Kong. chankh2@hkucc.hku.hk
authors.forename: K H
authors.initials: KH
authors.lastname: Chan
authors.forename: K M
authors.initials: KM
authors.lastname: Chan
authors.forename: Y L
authors.initials: YL
authors.lastname: Ho
authors.forename: Y P
authors.initials: YP
authors.lastname: Lam
authors.forename: H L
authors.initials: HL
authors.lastname: Tong
authors.forename: L L M
authors.initials: LL
authors.lastname: Poon
authors.forename: B J
authors.initials: BJ
authors.lastname: Cowling
authors.forename: J S M
authors.initials: JS
authors.lastname: Peiris
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000956:Antigens, Viral / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D019411:Clinical Laboratory Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D053122:Influenza A Virus, H3N2 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000821:virology*; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000821:virology*; D012680:Sensitivity and Specificity; D014773:Virology / Q000379:methods*; D055815:Young Adult
chemical_list: D000956:Antigens, Viral