Impact of population demographics on the utility of wastewater surveillance for early detection of community COVID-19 transmission

ABSTRACT Graphical abstract showing (1) wastewater sampling and RT-qPCR workflow; (2) temporal SARS-CoV-2 RNA trends with two surges; (3) COVID-19 community data by demographics; and (4) summary statements linking wastewater surveillance to disease burden. Wastewater-based epidemiology offers useful information about virus spread and community health. This study investigated the relationship between SARS-CoV-2 in wastewater and COVID-19 community health data in Bethlehem, Pennsylvania, parsed according to population demographics (zip code, age, sex, race, and preexisting health condition). Influent wastewater samples were collected from August 2020 to May 2021 and processed by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) to determine SARS-CoV-2 RNA concentrations; two surges in SARS-CoV-2 concentrations were observed in this timeframe. SARS-CoV-2 concentrations in wastewater were correlated with the number of active COVID-19 cases among each demographic group and each zip code within the study area. Variations in COVID-19 case counts across zip codes, age groups, sexes, racial groups, and individuals with underlying health conditions were observed, suggesting differences in transmission rates, testing availability and data collection, and/or adherence to preventative measures across demographic groups and the importance of applying targeted interventions and providing access to specialized health care for individuals at higher risk. Overall, study findings affirm the utility of wastewater surveillance as a predictive tool for monitoring COVID-19 transmission and underscore the importance of considering population demographics when interpreting community-level data.