BRIEF REPORT PERFORMANCE OF TWO COMMERCIAL FLUORESCENCE IMMUNOASSAYS FOR DETECTION OF INFLUENZA A AND B IN REPUBLIC OF KOREA
Performance of STANDARD F for influenza A and B
Keywords:
influenza A, influenza B, fluorescent immunoassay, STANDARD F Influenza A/B FIA, age stratification, nasopharyngeal swabAbstract
Fluorescence immunoassay (FIA) has become the method of choice for rapid detection of influenza. Here, we evaluated, using a multiplex real time polymerase chain reaction (RT-PCR) assay as reference, the performance of a newly developed STANDARD F Influenza A/B FIA equipped with a digital readout with that of Sofia Influenza A+B FIA on nasopharyngeal swab specimens (n = 16,810) collected from February 2015 to November 2019. For detection of influenza A, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of STANDARD F Influenza A/B FIA was 55.2%, 99.4%, 71.1%, and 98.7%, respectively, and 63.6%, 99.8%, 36.8%, and 99.9%, respectively for influenza B. Comparable values were obtained with Sofia Influenza A+B FIA, except specificity of influenza B detection is significantly lower compared to that of STANDARD F Influenza A/B FIA (p-value <0.001). When specimens were stratified according to age of subjects, STANDARD F Influenza A/B FIA sensitivity in detecting influenza A was highest for ≤18 years of age and lowest (reduced by ~50%) for 19-64 years of age. Due to lack of adequate positive samples, no comparative data were available for influenza B detection. In conclusion, STANDARD F Influenza A/B FIA demonstrated satisfactory performance for detecting influenza A and B, and could be used as a point-of-care detection method particular in children, with the caveat that negative results for adults should be confirmed by RT-PCR (at least in the detection of influenza A).