ABSTRACT
@#Introduction: Rapid diagnosis for influenza virus infection is essential for proper patient management, delivering prompt treatment and reducing unnecessary antiviral therapy. Early diagnosis helps in disease prevention and control. Real-time reverse transcription-polymerase chain reaction (RT-PCR) assay yields high sensitivity and specificity in detecting influenza virus infection. However, it is relatively expensive and requires trained personnel and special equipment. In this study, we compared two rapid influenza diagnostic tests (RIDTs): digital readout systems (STANDARD™ F Influenza A/B FIA, fluorescence immunoassay) and conventional visual confirmation (QuickNavi™-Flu2, chromatography immunoassay) with the real-time RT-PCR assay. Methods: Two hundred ninety-eight respiratory samples were obtained from patients suspected of influenza infection at Siriraj Hospital from December 2018 to December 2019. Results: Real-time RT-PCR results showed the detection of influenza A virus in 99 samples (60%), influenza B virus in 61 samples (37%) and co-infection by both viruses in 5 samples (3%) by the real-time RT-PCR assay. The QuickNavi™-Flu2 sensitivity for detecting influenza A and B viruses were 81.73% and 84.85%, and the specificity was 100%. The STANDARD™ F Influenza A/B FIA sensitivity for detecting influenza A and B viruses were 84.62% and 83.33%, respectively. The specificity for influenza A virus detection was 99.25% and 94.74% for influenza B virus. Conclusion: The STANDARD™ F Influenza A/B FIA and the QuickNavi™-Flu2 showed acceptable and comparable sensitivity and specificity. Both RIDTs are potential alternative methods of real-time RT-PCR for rapid screening of influenza virus infection.