Facility wastewater monitoring as an effective tool for pandemic infection control: An experience in COVID-19 pandemic with long-term monitoring.

Introduction: Since the first report of a novel coronavirus infection caused by SARS-CoV-2 in late 2019, the infection has spread rapidly and had a significant impact on our lives. In the early stages of the COVID-19 pandemic, there was no adequate testing system in place, despite an urgent need for infection control measures in student dormitories.

Methods: We have been monitoring SARS-CoV-2 in wastewater as part of our infection control efforts in the university facilities since fall 2020. In the four dormitories, absorbent cotton was placed in the drains that the facility wastewater passed through, and samples were collected twice a week and processed by RT-PCR for SARS-CoV-2. The dormitory residents were informed of the monitoring results the next morning.

Results: The positivity of residents in the dormitories was highly consistent with the positivity of wastewater. Wastewater was positive in 89 % of cases before any residents were tested and found positive. Facility wastewater monitoring showed sensitivities of 80.4 % and specificities of 87.6 %. No traceable resident-to-resident transmission of infection within the facility was confirmed during the study period.

Conclusion: Sampling a single wastewater outlet in a building for SARS-CoV-2 PCR can effectively indicate the presence or absence of COVID-19 cases and be very useful for infection control of a facility. This simple and effective monitoring is applicable to future outbreaks of both emerging and re-emerging infectious diseases.