Persistence of SARS-CoV-2 RNA in wastewater after the end of the COVID-19 epidemics

Although the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been widely detected in wastewater in many countries to track the COVID-19 pandemic development, it is still a lack of clear understanding of the persistence of SARS-CoV-2 in raw sewage, especially after the end of the COVID-19 pandemic event. To fill this knowledge gap, this study conducted a field trial on the SARS-CoV-2 presence in various wastewater facilities after the end of the COVID-19 epidemics in Beijing. The result showed that the wastewater treatment facility is a large SARS-CoV-2 repository. The viral RNA was still present in hospital sewage for 15 days and was continually detected in municipal WWTPs for more than 19 days after the end of the local COVID-19 epidemics. The T90 values of the SARS-CoV-2 RNA in raw wastewater were 17.17-8.42 days in the wastewater at 4 degrees C and 26 degrees C, respectively, meaning that the decay rates of low titer viruses in raw sewage were much faster. The results confirmed that the SARS-CoV-2 RNA could persist in wastewater for more than two weeks, especially at lower temperatures. The sewage systems would be a virus repository and prolong the presence of the residual SARS-CoV-2 RNA. The study could enhance further understanding of the presence of SARS-CoV-2 RNA in raw wastewater.

Automated summary

This study conducted a field trial on the presence of SARS-CoV-2 in wastewater facilities in Beijing after the end of the COVID-19 epidemics. The results showed that the wastewater treatment facility is a large repository for SARS-CoV-2. The viral RNA was still present in hospital sewage for 15 days and in municipal wastewater treatment plants for more than 19 days. The study highlights the persistence of SARS-CoV-2 RNA in wastewater, especially at lower temperatures.