Strategic use of SARS-CoV-2 wastewater concentration data could enhance, but not replace, high-resolution community prevalence survey programmes

Wastewater-based epidemiology (WBE) has been proposed as a tool for public health authorities to monitor community transmission of SARS-CoV-2 and other agents. Here, we review the utility of WBE for estimating SARS-CoV-2 prevalence using wastewater data from the Environmental Monitoring for Health Protection (EMHP) programme and prevalence data from the REal-time Assessment of Community Transmission-1 (REACT-1) study in England. Our analysis shows a temporally evolving relationship between wastewater and prevalence which limits the utility of WBE for estimating SARS-CoV-2 prevalence in high spatial resolution without a concurrent prevalence survey. We further characterise WBE for SARS-CoV-2 prevalence as i) vaccination-coverage-dependent and ii) variant-specific. Our work provides a gesopatial framework to map wastewater concentrations to public health boundaries, enabling public health authorities to interpret the relationship between wastewater and prevalence. We demonstrate that WBE can improve the cost efficiency and accuracy of community prevalence surveys which on their own may have incomplete geographic coverage or small sample sizes.