Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the most recent emerging pathogen that causes the current pandemic of COVID-19. Although the main transmission routes for SARS-CoV-2 considered by the Centers for Disease Control and Prevention (CDC) are respiratory droplets and close contact, mounting evidences have emerged that virus transmission likely also occurs by aerosols. Similarly, influenza viruses (FluV) are transmitted via respiratory droplets, aerosols, and contact. More importantly, co-infection with FluV and SARS-CoV-2 has been observed in patients. With expected concurrent circulation of SARS-CoV-2 and FluV in the future, multiplexed collection and detection of various airborne viruses are desirable for studying transmission routes, planning and allocating resources, and mitigating the impact on public health. The collection of airborne viruses requires air samplers, ideally with two following features. One is to have the collected samples analyzed at the point-of-care (POC), rather than being sent to a lab with a delay of 1-2 days in reporting the test results. The second feature is to efficiently collect virus aerosols directly into a liquid, rather than onto a filter, for subsequent virus analysis. While liquid impingers are effective in collecting microparticles (such as bacteria), they are less so for nanoparticles such as viruses. To realize these features, we have developed (1) a Viable Virus Aerosol Sampler (VIVAS) that shows high collection efficiency of virus particles by enlarging nanometer-sized virus aerosols into micrometer-sized droplets through water vapor condensation; and (2) a Valve-enabled Lysis, paper-based RNA Enrichment, and RNA Amplification Device (VLEAD) that carries out virus lysis and washing steps without pipetting, followed by reverse transcription loop- mediated isothermal amplification (RT-LAMP) for accurate genetic identification. In this proposed research, we aim to integrate VIVAS with VLEAD for multiplexed airborne virus collection and detection at POC, assess the integrated system for collection and multiplexed detection of SARS-CoV-2 and FluV, and validate the system in real-world applications by surveying airborne viruses in a health clinic and public venues. The significance of the proposed research lies in the following aspects. First, it will lead to an innovative system that can collect and detect airborne SARS-CoV-2 and FluV at POC, which will help address a major public health concern (i.e., current COVID-19 pandemic and expected concurrent circulation with FluV in the flu seasons). Second, the integrated system will provide a critically important tool to study the role of airborne route in virus transmission. If confirmed, appropriate personal protection equipment and other remedies will be employed to reduce infections among healthcare workers and the general public. Third, the system is capable of conducting environmental surveillance via efficient collection and timely detection of these viruses at POC. It can function as a rapid mass screening method for timely results that will be valuable for local policymakers to issue prompt warning to the public and for hospitals to prepare for local outbreaks and clinical care.
An integrated sampling and testing platform capable of collecting and detecting airborne viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses, at the point-of-care (POC) can be useful for studying virus transmission, planning and allocating resources, and mitigating the impact on public health.
