Multi-scenario surveillance of respiratory viruses in aerosols with sub-single-copy spatial resolution
Nature Communications volume 15, Article number: 8770 (2024 ) Cite this article
Highly sensitive airborne virus monitoring is critical for preventing and containing epidemics. However, the detection of airborne viruses at ultra-low concentrations remains challenging due to the lack of ultra-sensitive methods and easy-to-deployment equipment. Here, we present an integrated microfluidic cartridge that can accurately detect SARS-COV-2, Influenza A, B, and respiratory syncytial virus with a sensitivity of 10 copies/mL. When integrated with a high-flow aerosol sampler, our microdevice can achieve a sub-single-copy spatial resolution of 0.83 copies/m3 for airborne virus surveillance with an air flow rate of 400 L/min and a sampling time of 30 minutes. We then designed a series of virus-in-aerosols monitoring systems (RIAMs), including versions of a multi-site sampling RIAMs (M-RIAMs), a stationary real-time RIAMs (S-RIAMs), and a roaming real-time RIAMs (R-RIAMs) for different application scenarios. Using M-RIAMs, we performed a comprehensive evaluation of 210 environmental samples from COVID-19 patient wards, including 30 aerosol samples. The highest positive detection rate of aerosol samples (60%) proved the aerosol-based SARS-CoV-2 monitoring represents an effective method for spatial risk assessment. The detection of 78 aerosol samples in real-world settings via S-RIAMs confirmed its reliability for ultra-sensitive and continuous airborne virus monitoring. Therefore, RIAMs shows the potential as an effective solution for mitigating the risk of airborne virus transmission.
The unprecedented crisis caused by the coronavirus disease 2019 (COVID-19) has cast an immense shadow over global public health1,2. Compelling epidemiological data highlight that the airborne transmission of SARS-CoV-2 contributed significantly to the COVID-19 pandemic3,4,5,6,7. Activities such as exhaling, speaking, or singing by an infected person can all generate virus-laden droplets which rapidly coalesce into aerosol particles with a diameter of less than 5 μm3. These tiny SARS-CoV-2 particles can spread up to 10 m away and have an average half-life of 1–3 h (other common respiratory viruses, such as respiratory syncytial virus and influenza, have similar or potentially longer half-lives)8,9,10,11,12, greatly increasing the risk of infection to nearby people. In the past few years, it has been proved that SARS-CoV-2 can be transmitted by aerosols in various locations, such as hospitals6,13, community settings14, public transportation15,16, schools17,18, bars17, and gymnasiums18, even causing so-called “super-spreading events”19,20. As a result, deploying rapid and sensitive surveillance devices for monitoring contagious bioaerosols in highly crowded places has been gradually regarded as an efficient and non-invasive means to contain the disease spreading without interrupting normal social activities21,22.
