Near-source wastewater surveillance of SARS-CoV-2, norovirus, influenza virus and RSV across five different sites in the UK

Abstract

By tracking infectious diseases through sewage, municipal-scale wastewater surveillance has provided early warnings of future COVID-19 hospitalisations, identified biases in diagnostic testing, and is rapidly expanding to a broader array of pathogens. Despite applications in the targeted delivery of local interventions, near-source wastewater surveillance has received less attention and we know little about the near-source time series dynamics of contrasting pathogens. To address this, we conducted wastewater surveillance at five sites for SARS-CoV-2 and two sites for norovirus GI, norovirus GII, influenza A virus, influenza B virus, and human respiratory syncytial virus (RSV A and RSV B). Sites were selected for contrasting functions: an office, charity centre, museum, university, and care home. The key findings are (1) near-source wastewater detections were linked to local events (staff sickness, enhanced cleaning, changing populations); (2) wastewater detections decreased in the order norovirus GII > norovirus GI > SARS-CoV-2 ≈ influenza A ≈ RSV A > influenza B ≈ RSV B; (3) correlation between near-source wastewater data and national surveillance data increases as a function of catchment size and viral prevalence (examples include the SARS-CoV-2 BA.4/BA.5 variant peak at a museum and wastewater tracking the winter norovirus season); (4) strong weekday periodicity in near-source wastewater SARS-CoV-2 detections, with the correlation against COVID-19 case numbers increasing when modelling variable lag times between faecal shedding onset and clinical diagnosis (R2 = 0.45 increases to 0.84-0.86); (5) a log-linear relationship between the frequency of wastewater SARS-CoV-2 detection and log(catchment size viral prevalence) (R2 = 0.6914-0.9066). Finally, we propose two use cases. Firstly, for rare or high-risk pathogens, near-source wastewater sentinel systems provide early warning of outbreaks, achieving high frequency community coverage without behaviour change and at low cost versus diagnostic testing. Secondly, for endemic pathogens, near-source wastewater reveals long-term patterns and trends, the effectiveness of local policies, and community vulnerabilities.