Scotland’s SARS-CoV-2 Wastewater Monitoring Program can Help Prevent Future Virus Outbreaks

covid in scotland wastewater analysis
Wastewater-based epidemiology allows for precise analysis and thorough monitoring of the virus distribution. Source: Alamy

Despite the fact that the COVID-19 pandemic is coming to an end, the virus itself is still there, easily transmittable and infectious. New virus strains that appear at certain points increase the risks of massive infection outbursts. This is why virus monitoring is so important at any time.

A group of researchers from Scotland noted that the presence of SARS-CoV-2 particles in the feces of people infected with the virus correlates with the amount detected in COVID-19 community testing. In a recent study posted to the medRxiv preprint server, researchers reported on the use of the wastewater-based epidemiology (WBE) approach to evaluate the levels of severe acute respiratory syndrome coronavirus 2 ribonucleic acid (RNA) shed into the Scottish sewage networks, during the coronavirus disease 2019 (COVID-19) pandemic. They believe that sewage surveillance has the potential to detect SARS-CoV-2 outbreaks at an early stage.

About the Study

The study used the near-real-time dataset of a nationwide program conducted by Scottish Water (the governmental water treatment company) and the Scottish environmental protection agency (SEPA) between May 2020 and February 2022. Wastewater samples were collected from 122 Scottish water facilities and transferred to SEPA laboratories for future analysis. Then, SARS-CoV-2 RNA was extracted from the samples and quantified. New samples were collected once or twice per week using a 24-hour-autosampler or a grab sample from maintenance holes.

The data obtained were shared on SEPA’s public dashboards and with the Government of Scotland. In addition, the datasets were shared in open online platforms and repositories such as GitHub, protocols.io, and Zenodo. Data were normalized for the final analysis, based on information such as the site population, incoming wastewater flow values, and ammonia content, and expressed as million gene copies per person per day [Mgc/pD]. Statistical analysis was performed using the biomathematics and statistics Scotland (BioSS) and the data were presented in the Scottish government reports, published weekly.

Results

The study managed to present precise SARS-CoV-2 spreadness levels for the majority of regions of Scotland. 6% of the study samples could not be categorized. Data normalization showed that data obtained by the WBE approach correlated well with data published by local health authorities on the SARS-CoV-2 pandemic waves.

Wastewater-based epidemiology allows for precise analysis and thorough monitoring of the virus distribution. In the future this type of analysis will grant researchers an opportunity to predict and prevent dangerous virus outbursts. This works not only for the coronavirus type, but for similar virus groups as well.