Establishment of Wastewater-Based Sars-Cov-2 Monitoring System in South Korea Over the Past Two Years

Here, we utilized the wastewater surveillance tool to monitor the Coronavirus disease 19 (COVID-19) outbreak for the first time in Korea. The sampling campaigns have been done from the wastewater treatment plants (WWTPs) in the capital city of Korea, Seoul, and in the first place of a severe outbreak, the Daegu. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA has been extracted from the collected wastewater influent and primary sewage sludge samples. The results were compared with the COVID-19 cases in the WWTPs served area. In addition, microbial community changes before and after the COVID-19 outbreak and SARS-CoV-2 variants by whole transcriptome sequencing were analyzed.Results showed that the trends in SARS-CoV-2 RNA concentrations in the influent and sludge matched the trends of reported COVID-19 cases, especially sludge showed high-resolution data, which is well-matched when fewer COVID-19 cases (0~250) are reported. We detected the SARS-CoV-2 Beta variant (South Africa, B.1.351) in the wastewater 1 month earlier than the clinical report. In addition, the microbial community was compared before and after the outbreak and found that the Aeromonas bacterial species was dominated (21.2%) among other bacterial species, indicating the possible indirect microbial indicator of the COVID-19 outbreak. Our findings suggest a potential pandemic disease monitoring system via community-level wastewater infrastructure with appropriate control strategies.