Point-of-Care Detection of Airborne Respiratory Viruses

AMIN SHIRKHANI, Morteza Alipanah, Matthew D. Jansen, William B. Vass, Sripriya Nannu Shankar, Carlos Manzanas, Mohammad Washeem, Z. Hugh Fan, John Lednicky, Chang-Yu Wu, University of Miami

     Abstract Number: 23
     Working Group: Health-Related Aerosols

Abstract
Analytical methods commonly used to detect viruses often yield results too slowly to produce information that is actionable for the protection of individuals exposed during the sampling period. Point-of-care (POC) detection of respiratory viruses collected during air sampling facilitates faster responses for exposure risk mitigation. In this study, we designed and fabricated an adaptor that integrates the air sampler called Viable Virus Aerosol Sampler (VIVAS) with a POC device called Valve-enabled Lysis, paper-based RNA Enrichment, and RNA Amplification Device (VLEAD). This adaptor serves as the sample collector within VIVAS and then interfaces with VLEAD to transfer the virus collection medium after sampling for POC analysis using a ball valve. The adaptor design was initially optimized through computational fluid dynamics modeling, showing a 95% collection efficiency for particles with aerodynamic diameters of 3 µm or larger. Experimental evaluation using an Aerodynamic Particle Sizer confirmed this, indicating an average physical collection efficiency of approximately 94%, consistent with our modeling results. We tested the integrated VIVAS-VLEAD system using lab-generated human coronavirus OC43, which served as a surrogate for SARS-CoV-2. Results indicated 100% success in detecting viruses in samples containing 103 to 104 genome equivalents (GE) of virus per sample, where concentrations were verified by RT-qPCR. Success in detecting viruses in samples containing 102 GE was 33%. Results show that the adapter can effectively collect viruses and transfer them to VLEAD, replacing the standard Petri dish used for collecting aerosol particles in VIVAS. Work reported herein suggests that the VIVAS-VLEAD system can be used for POC virus detection because its limit of detection is comparable to the level at which SARS-CoV-2 has been collected by VIVAS during environmental sampling reported in other studies.