The SARS-CoV-2 surveillance of sewage and water bodies project was launched in June 2020. Since then, weekly composite samples provided by Irish Water from the influent of Ringsend (Dublin), Shanganagh-Bray and Enniskerry wastewater treatment plants are analysed in Prof Wim Meijer’s laboratory. 

To measure the levels,  250 ml of each 24h-composite sewage sample is concentrated until a volume of 250 µl - 1 ml is obtained. After viral RNA extraction,  RT-qPCR assays for three viral markers are performed to detect the presence of the virus. This process takes around seven hours. Weekly reports are provided to NPHET, the Irish Epidemiological Modelling Advisory Group, the National Virus Reference Laboratory (NVRL) and Irish Water. 

The levels of SARS-CoV-2 RNA have significantly increased compared to levels during the summer, and closely match clinical data from the same period. Thus, wastewater offers an aggregate sample from an entire community and combined with clinical data allows critical monitoring of SARS-CoV-2 transmission within a community. This wastewater surveillance project is of immediate benefit to public health and our community  in identifying early COVID-19 warnings outbreaks.

This research is part funded by the European Regional Development Fund through the Ireland Wales Cooperation Programme as part of the Acclimatize operation and by Science Foundation Ireland (20/COV/0159).