Observed Differences in Wastewater Measurements of <i>Treponema pallidum</i> , Norovirus, and SARS-CoV-2 in Detroit Metropolitan Areas with Different Socioeconomic Vulnerabilities

Wastewater surveillance of viral and bacterial pathogens, covering communities with varying social vulnerabilities, is needed. Incorporating communities with high social vulnerability index (SVI) scores in wastewater surveillance programs is a critical direction suggested by the National Wastewater Surveillance System (NWSS) Phase II report and numerous studies. This paper describes one of the first investigations demonstrating differences between viral (SARS-CoV-2 and norovirus) and bacterial (Treponema pallidum) concentrations in municipal wastewater in geographic areas with varying SVI scores. We investigated two interceptor-served urban sewersheds in the Detroit Metropolitan Area (DMA), Michigan, covering communities with substantial differences in SVI scores, including Great Lakes Water Authority’s (GLWA) Detroit River Interceptor (DRI) and North Interceptor East Arm (NIEA). We identified contrasting differences in overall SVI scores and themed SVI scores between DRI-covered and NIEA-covered areas. Notably, pepper mild mottle virus (PMMoV)-normalized SARS-CoV-2 and T. pallidum exhibited higher concentrations in DRI-covered than NIEA-covered sewersheds. Conversely, PMMoV-normalized norovirus concentrations did not present distinct differences between the two sewersheds. The results confirm that socioeconomic differences affect communicable disease occurrence, and wastewater surveillance may be used to track and predict those differences for certain diseases.