The global pandemic caused by SARS-CoV-2 has highlighted the need for improved public health surveillance measures to track and predict the outbreak of disease in a community. While many innovative measures have been proposed in recent years to accomplish this task, one method gaining increasing traction for urban surveillance of SARS-CoV-2 transmission is wastewater testing for genetic evidence of the virus (Sherchan, 2020). SARS-CoV-2 is known to cause COVID-19 disease which is proven to be spread through both aerosolized respiratory secretions, as well as fecal shedding (Schmitz, 2021). Through regular sampling of a community’s wastewater, public health officials are able to detect early signs of viral shedding with increased prevalence of SARS-CoV-2 RNA. These methods are proven to precede a spike in nasopharyngeal swabbing test positivity rates, as well as an increase in hospitalizations in a community for COVID-19 (McMahan, 2021). Utilizing wastewater testing allows for public health officials to have an insight into upcoming increases in disease burden to their community.
Currently, most wastewater surveillance programs are accomplished through regimented examination of filters put in sewage lines, or water samples acquired from wastewater treatment plants which are then prepared for nucleic acid extraction and RT-PCR amplification to detect the presence of known SARS-CoV-2 genetic targets. Standard methods for preparation of filters involve long processing times and incubations on ice which can be a burden to high-throughput workflows. Herein, we examine a streamlined methodology for filter homogenization utilizing the Omni Bead Ruptor Elite™ bead mill homogenizer followed by automated RNA extraction on the chemagic™ Prime™ in preparation for RT-PCR detection of SARS-CoV-2 spiked wastewater samples. This high throughput methodology provides a robust workflow for detection of SARS-CoV-2 RNA in wastewater samples.
Table 1: Ct, Average Ct, and Viral Copies/μL obtained from SARS-CoV-2 identification from each wastewater filter processed following the proposed detection workflow.