Spatial and Temporal Monitoring of SARS-CoV-2 in a Sewershed

ABSTRACT

In response to the global pandemic, Clean Water Services (Washington County, Oregon) monitored 4 wastewater treatment plants (WWTPs) and 16 manholes over a period of 15 months to determine whether spatial and temporal trends in SARS-CoV-2 concentrations corresponded with reported COVID-19 cases. A total of 738 samples were analyzed for SARS-CoV-2 using reverse transcription droplet digital polymerase chain reaction (RT-ddPCR). SARS-CoV-2 concentrations at WWTPs appeared to be a leading indicator, with increases in wastewater observed two to three weeks before cases rose. Neighborhoods with high LatinX and high poverty populations also had higher SARS-CoV-2 concentrations. Additionally, outbreaks at local food processing plants corresponded with viral peaks in their associated manhole. Surprisingly, SARS-CoV-2 was rarely detected in hospital effluent despite the presence of known cases, and experiments revealed hospital disinfectants can destroy the RNA signal. Collectively, these findings demonstrate the value of wastewater-based epidemiology for monitoring the local burden of COVID-19. Copyright © 2021 Water Environment Federation