GENEDIA Multi Influenza Ag Rapid Test for detection and H1, H3, and H5 subtyping of influenza viruses

Background: Rapid identification and subtype determination of influenza virus is important in managing infected patients. Rapid influenza diagnostic tests (RIDTs) are widely used in this manner, but most can only detect influenza A and B viruses without subtyping. A new RIDT, GENEDIA Multi Influenza Ag Rapid Test (GENEDIA), was developed for detection of influenza A and B viruses and also subtyping of influenza A to H1, H3, H5 which has not been possible with other RIDTs. Objectives: Assess the performance of GENEDIA. Study design: Nasopharyngeal swabs were collected from 274 clinically suspected patients (influenza A/H1N1/2009 (n= 50), influenza A/H3 ( n= 50), influenza B (n= 73) and influenza-negative (n= 101)) and analyzed with the real-time RT-PCR, GENEDIA, SD Bioline Influenza Ag, and Alere BinaxNow Influenza A&B Card. Also, 46 fecal specimens (H5N2 (n= 3), H5N3 (n= 3)) of spot-billed duck were analyzed with RT-PCR and GENEDIA. Results: Compared to real-time RT-PCR, the sensitivities of GENEDIA, SD Bioline Influenza Ag, and Alere BinaxNow Influenza A&B Card were 73.0%, 57.0%, 58.0% for influenza A, respectively, and 68.5%, 65.8%, 57.5% for influenza B, respectively. Specifically, the sensitivity of GENEDIA was 70.0% for influenza A/H1N1/2009 and 76.0% for influenza A/H3. From the avian influenza samples, GENEDIA detected all six H5 subtype without any cross-reactions. Conclusion: The GENEDIA Multi Influenza Ag Rapid Test was sensitive in detecting influenza viruses compared with other commercial RIDTs and also useful for rapid subtype determination of influenza A.