Monitoring SARS-CoV-2 Using Infoveillance, National Reporting Data, and Wastewater in Wales, United Kingdom: Mixed Methods Study (Preprint)

Abstract

BACKGROUND The COVID-19 pandemic necessitated rapid real-time surveillance of epidemiological data to advise governments and the public, but the accuracy of these data depend on myriad auxiliary assumptions, not least accurate reporting of cases by the public. Wastewater monitoring has emerged internationally as an accurate and objective means for assessing disease prevalence with reduced latency and less dependence on public vigilance, reliability, and engagement. How public interest aligns with COVID-19 personal testing data and wastewater monitoring is, however, very poorly characterised. OBJECTIVE This study assesses the associations between internet search volume data relevant to COVID-19, public healthcare statistics and national-scale wastewater monitoring of SARS-CoV-2 across South Wales, UK over time to investigate how interest in the pandemic may reflect the prevalence of SARS-CoV-2, as detected by national testing and wastewater monitoring. METHODS Relative search volume data from Google Trends for search terms linked to the COVID-19 pandemic were extracted and compared against government-reported COVID-19 statistics and RT-qPCR SARS-CoV-2 data generated from wastewater in South Wales, UK, using multivariate linear models and correlation analysis. RESULTS Wastewater monitoring data suggests that prevalence of the virus exceeded that reported in self-testing national reports. Google search volumes surrounding the COVID-19 pandemic also decreased across the same period, potentially suggesting a reduction in public interest is reflected in lower volumes of self-testing and reporting with consequential loss of accuracy of those data. CONCLUSIONS Wastewater monitoring presents a valuable means for assessing population-level prevalence of SARS-CoV-2. The importance of such monitoring is increasingly clear as a means of objectively assessing the prevalence of COVID-19 despite the dynamic interest and participation of the public. Increased accessibility of wastewater monitoring data to the public, as is the case for other national data, may enhance public engagement with these forms of monitoring.