(627h) A Nove Microfluidic Technique for Detecting Clinical Isolates of Inluenza A Virus

This work presents the clinical application of a robust and unique approach for RNA amplification, called a Simple Method for Amplifying RNA Targets (SMART), for the detection and subtype identification of H1N1 swine, H1N1 seasonal, and H3N2 seasonal influenza virus. While all the exciting amplification techniques rely on the diffusion of two molecules to complex RNA structures, the SMART method achieves fast and efficient amplification via single molecule diffusion. SMART utilizes amplifiable single stranded DNA (ssDNA) probes serve as reporter molecules for specific viral RNA (vRNA) sequences that are captured and separated on a microfluidic chip under zero-flow conditions. The assay is performed using an isothermal (41°C) amplification scheme via a modified version of nucleic acid sequence based amplification (NASBA). In our study, 116 consecutive, de-identified, clinical nasopharyngeal swab samples were analyzed independently and in a blinded fashion using SMART, PCR, antigen (Ag) testing, and quantitative viral culture. SMART correctly detected influenza in 98.3% of the samples with a subtyping accuracy of 95.7% for viral loads as low as 10⁵ copies/mL and provides subtyping information unmatched to any other diagnostic test, while also performing at 60 times faster than the gold standard of viral culture. This work demonstrates that SMART represents a highly accurate, point-of-care (POC) diagnostic platform for the detection and subtyping of influenza virus in clinical specimens and offers significant advantages over current commercially available diagnostic tools.