Recovery and degradation of mammalian virus RNA during high-flow filter sampling

Environmental surveillance of emerging viral pathogens is necessary for defining and mitigating future outbreaks. These programs can take multiple complementary forms, such as wastewater surveillance, xenosurveillance, and air sampling. For the latter, air samplers can be categorized into major types based on airflow and collection media. Higher-flow air sampling, such as that exceeding 150 L per minute, is typically required to characterize aerosols in large areas, including hatcheries, dairies, and ports of entry. Until recently, higher flow air samplers exclusively collected airborne particulate matter on dry filter media. The SASS 3100 Dry Air Sampler, with its high sampling rate and compact size, offers a potential solution for these settings. While the SASS 3100 sampler has successfully collected SARS-CoV-2 RNA from hospital air, concerns exist about viral sample degradation on the filter media during aerosol collection. In response, we present data from several controlled chamber studies using a variety of common mammalian viruses. We observed no significant sample degradation in trials collecting rabbit hemorrhagic disease virus 2, and influenza A virus using a SASS 3100 over an 8-h sampling period, operating at a 300 L per minute flow rate. These results support expanded use of the SASS 3100 for the quantitative recovery of airborne mammalian viruses and provide a framework for further stability studies with other airborne microorganisms.