Detection of SARS-CoV-2 in Northern Ireland Wastewater

SARS-CoV-2 is shed in high levels in the faeces and urine leading to wastewater-based epidemiology (WBE) becoming an integral part of the response to the global pandemic. SARS-CoV-2 is shed by asymptomatic, symptomatic and pre-symptomatic individuals, meaning that wastewater testing can be used as an early warning sign for outbreaks in certain geographical areas. The potential to assess infection levels in large populations as well as being considerably cheaper and less invasive than clinical testing further contributes to WBE’s importance during the pandemic. Multiple countries, including those found in the rest of the United Kingdom, have active WBE programmes. Throughout Northern Ireland (NI), 31 Wastewater Treatment Inlets are part of a routine screening programme for SARS-CoV-2 in wastewater. These sites capture 62% of the NI population, which gives an important snapshot of infection levels among the NI population in different localities. Data generated has been vitally important to the public health response and stakeholder decision making within NI. In this study we evaluate numerous wastewater processing methods to ensure maximum viral recovery from each sample. Optimising processing methods is important in ensuring that samples are not below our limit of detection and therefore inaccurately declared negative.