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Updated: May 19, 2026
High-throughput Detection Method for Influenza Virus
Published on: February 4, 2012
Evaluation of Sofia fluorescent immunoassay analyzer for influenza A/B virus
Chang Kyu Lee1, Chi Hyun Cho, Mi Kyung Woo
1Department of Laboratory Medicine, Brain Korea 21 Graduate School of Medicine, College of Medicine, Korea University, Seoul, Republic of Korea. cklee@korea.ac.kr
Background:
The influenza virus causes seasonal epidemics which are associated with high morbidity and mortality. Rapid diagnostics tests (RDT) are frequently used to make a quick influenza diagnosis to confirm the clinical suspicion, despite their low sensitivity.
Objectives:
Assess the performance of the Sofia Influenza A+B Fluorescence Immunoassay (Quidel, San Diego, CA).
Study Design:
Nasopharyngeal swabs, taken from 241 patients (influenza A (n=73)/B (n=72), negative samples (n=96)) were analyzed using the Sofia Influenza A+B Fluorescence Immunoassay, BinaxNOW Influenza A/B antigen kit (Alere Inc., USA), Directigen EZ Flu A and B (Becton Dickinson, USA), real-time RT-PCR and an influenza virus culture.
Results:
There was a significant difference between the performance of rapid antigen tests and the Sofia FIA, when compared to the RT-PCR, in the detection of influenza strain A and B. Indeed, the Sofia FIA displayed sensitivities of 82.2% and 77.8% for strains A and B respectively, whereas sensitivities of BinaxNOW Influenza A/B antigen kit, and Directigen Flu A and B were 54.8%, and 68.5% for influenza A, and 62.5%, and 52.8% for influenza B respectively. The average RT-PCR threshold cycle (C(t)) (±SD) for the Sofia Influenza A+B Fluorescence Immunoassay-positive specimens was higher than those of the BinaxNOW Influenza A/B antigen and the Directigen EZ Flu A and B kit positive specimens.
Conclusion:
Compared to other RDTs, the Sofia Influenza A+B Fluorescence Immunoassay is a sensitive, and rapid method for the detection and discrimination between influenza A and B.
