Fluorescent Immunochromatography for Rapid and Sensitive Typing of Seasonal Influenza Viruses

Abstract

Lateral flow tests also known as Immunochromatography (IC) is an antigen-detection method conducted on a nitrocellulose membrane that can be completed in less than 20 min. IC has been used as an important rapid test for clinical diagnosis and surveillance of influenza viruses, but the IC sensitivity is relatively low (approximately 60%) and the limit of detection (LOD) is as low as 10³ pfu per reaction. Recently, we reported an improved IC assay using antibodies conjugated with fluorescent beads (fluorescent immunochromatography; FLIC) for subtyping H5 influenza viruses (FLIC-H5). Although the FLIC strip must be scanned using a fluorescent reader, the sensitivity (LOD) is significantly improved over that of conventional IC methods. In addition, the antibodies which are specific against the subtypes of influenza viruses cannot be available for the detection of other subtypes when the major antigenicity will be changed. In this study, we established the use of FLIC to type seasonal influenza A and B viruses (FLIC-AB). This method has improved sensitivity to 100-fold higher than that of conventional IC methods when we used several strains of influenza viruses. In addition, FLIC-AB demonstrated the ability to detect influenza type A and influenza type B viruses from clinical samples with high sensitivity and specificity (Type A: sensitivity 98.7% (74/75), specificity 100% (54/54), Type B: sensitivity 100% (90/90), specificity 98.2% (54/55) in nasal swab samples) in comparison to the results of qRT-PCR. And furthermore, FLIC-AB performs better in the detection of early stage infection (under 13h) than other conventional IC methods. Our results provide new strategies to prevent the early-stage transmission of influenza viruses in humans during both seasonal outbreaks and pandemics.

Evaluation of Lateral-Flow Assay for Rapid Detection of Influenza Virus

“…However, in our study, the sensitivity of LFA to detect influenza viruses A and B was not significantly different. Further analysis found that in one of the included literatures, LFA was more sensitive in detecting influenza virus B than influenza virus A in nasal swabs [ 29 ]. Therefore, we infer that collecting nasal swab samples may enhance the sensitivity of detecting influenza virus B.…”

Smartphone-Based Fluorescent Diagnostic System for Highly Pathogenic H5N1 Viruses

“…The reported performance of conventional immunoassay RDTs was about 7 × 10 4 - 7 × 10 5 PFU/mL for H5N3 34 , 35 . Recently, various approaches have been applied to improve the rapid diagnostic systems for accurate and quick analysis with different influenza subtype viruses; A fluorescent immunochromatographic test for seasonal influenza viruses has been reported to detect H5N1 virus at 83.7 PFU/reaction, but the clinical study was performed only with Influenza A type, not H5N1 36 . Although recent developments in rapid diagnostic tests employ nanomaterials, including nanoparticles 37 and graphene films 38 , to detect influenza H5 recombinant antigen, such methods still need further improvements and verification in clinical environments.…”

Development of a smartphone-based rapid dual fluorescent diagnostic system for the simultaneous detection of influenza A and H5 subtype in avian influenza A-infected patients

“…Given the demand for multiplex testing and the major advantages of the lateral flow assay over alternative rapid diagnostic platforms, this study aimed to adapt the simplicity of the membrane-based lateral flow assay and multiplex techniques. Various fluorescent materials have been applied for lateral flow assays as alternative to conventional gold nanoparticles to detect influenza A as POCT [11][12][13][14][15][16]. Also, self-contained and disposable diagnostic devices have been developed [15,[17][18][19].…”