Estimating SARS-CoV-2 prevalence from large-scale wastewater surveillance: insights from combined analysis of 44 sites in England (preprint)

Accurate surveillance of the COVID-19 pandemic can be weakened by under-reporting of cases, particularly due to asymptomatic or pre-symptomatic infections, resulting in bias. Quantification of SARS-CoV-2 RNA in wastewater (WW) can be used to infer infection prevalence, but uncertainty in sensitivity and considerable variability has meant that accurate measurement remains elusive. Data from 44 sewage sites in England, covering 31% of the population, shows that SARS-CoV-2 prevalence is estimated to within 1.1% of estimates from representative prevalence surveys (with 95% confidence). Using machine learning and phenomenological models, differences between sampled sites, particularly the WW flow rate, influence prevalence estimation and require careful interpretation. SARS-CoV-2 signals in WW appear 4–5 days earlier in comparison to clinical testing data but are coincident with prevalence surveys suggesting that WW surveillance can be a leading indicator for asymptomatic viral infections. Wastewater-based epidemiology complements and strengthens traditional surveillance, with significant implications for public health.

Detection and Survival of SARS-coronavirus in Human Stool, Urine, Wastewater and Sludge (preprint)

The COVID-19 pandemic has revealed many knowledge gaps with implications toward the speed and nature of our response to contain, assess and mitigate risk. The routine discharge of treated and untreated wastewater into rivers and coastal waters has placed SARS-CoV-2 viability in wastewater at the centre of an emerging hazard and potential risk to water industry workers and the public who come into contact with sewage-impacted water. Here we provide a review of the Severe Acute Respiratory Syndrome coronavirus primary literature that presents the evidence base pertaining to the key questions of whether the SARS-CoV-1 and SARS-CoV-2 is shed in stool and urine, is recoverable, and infectious in wastewater. We discuss the challenges posed by the current literature base and the extent to which the current evidence is fit for the purpose of informing robust human and environmental risk assessments.