Dynamics of SARS-CoV-2 variants in southwest Ohio municipal wastewater

Abstract

Wastewater surveillance has proven to be a widely useful means for tracking the dynamics of COVID-19, particularly as the emphasis on clinical testing and reporting of case data continues to decline. Here we present wastewater monitoring data from a multi-year sampling campaign at 11 wastewater collection facilities in Ohio. We found strong correlations between flow-adjusted wastewater concentrations of the virus (as represented through quantification of N2 gene fragments) and reported cases and used sequencing to confirm the sequential arrival of several variants of concern (VOCs) between winter 2020 and spring 2022. We observed that the three main VOCs in our dataset, alpha, delta, and omicron, showed differing temporal dynamics like length of time from first detection to dominating the wastewater signal. We also found credible variation in the relationship between wastewater concentration and clinical cases during different periods within our time series (delineated based on the dominant VOC), indicating the possibility of differential fecal shedding by the three variants.