title: Evaluation of indirect fluorescent antibody assays compared to rapid influenza diagnostic tests for the detection of pandemic influenza A (H1N1) pdm09.
abstract: Performance of indirect fluorescent antibody (IFA) assays and rapid influenza diagnostic tests (RIDT) during the 2009 H1N1 pandemic was evaluated, along with the relative effects of age and illness severity on test accuracy. Clinicians and laboratories submitted specimens on patients with respiratory illness to public health from April to mid October 2009 for polymerase chain reaction (PCR) testing as part of pandemic H1N1 surveillance efforts in Orange County, CA; IFA and RIDT were performed in clinical settings. Sensitivity and specificity for detection of the 2009 pandemic H1N1 strain, now officially named influenza A(H1N1)pdm09, were calculated for 638 specimens. Overall, approximately 30% of IFA tests and RIDTs tested by PCR were falsely negative (sensitivity 71% and 69%, respectively). Sensitivity of RIDT ranged from 45% to 84% depending on severity and age of patients. In hospitalized children, sensitivity of IFA (75%) was similar to RIDT (84%). Specificity of tests performed on hospitalized children was 94% for IFA and 80% for RIDT. Overall sensitivity of RIDT in this study was comparable to previously published studies on pandemic H1N1 influenza and sensitivity of IFA was similar to what has been reported in children for seasonal influenza. Both diagnostic tests produced a high number of false negatives and should not be used to rule out influenza infection.
authors.affiliation: Epidemiology & Assessment, Orange County Health Care Agency, Santa Ana, California, United States of America. snutter@ochca.com
authors.forename: Sandra
authors.initials: S
authors.lastname: Nutter
authors.forename: Michele
authors.initials: M
authors.lastname: Cheung
authors.forename: Felice C
authors.initials: FC
authors.lastname: Adler-Shohet
authors.forename: Kathryn
authors.initials: K
authors.lastname: Krusel
authors.forename: Kate
authors.initials: K
authors.lastname: Vogel
authors.forename: Hildy
authors.initials: H
authors.lastname: Meyers
mesh_terms: D000328:Adult; D002140:California / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005188:False Negative Reactions; D005189:False Positive Reactions; D005455:Fluorescent Antibody Technique / Q000379:methods / Q000592:standards*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics*; D007251:Influenza, Human / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D007297:Inpatients / Q000706:statistics & numerical data; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods / Q000592:standards*; D010045:Outpatients / Q000706:statistics & numerical data; D058873:Pandemics; D016133:Polymerase Chain Reaction / Q000379:methods / Q000592:standards*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity