COVID-19 Wastewater Surveillance Study Reveals Shifting Relationship to Clinical Disease

Stanford University researchers reporting in JAMA Network Open present findings from a wastewater testing-based analysis of SARS-CoV-2 infections in the US during 2022. Using PCR-based analyses, the team assessed wastewater samples collected between January and September from 268 counties spanning 22 US states, demonstrating that higher-than-usual levels of SARS-CoV-2 circulating in wastewater samples tended to coincide with increased case reports and COVID-19 hospitalization levels in the first few months of the year. After the first quarter of 2022, on the other hand, the authors saw separation between wastewater levels of the virus and apparent clinical severity of disease, potentially owing to improved treatment and vaccination options that dialed down the virulence associated with infections. Even so, they suggest, the current results indicate that "wastewater surveillance can provide an accurate assessment of county SARS-CoV-2 incidence and may be the best metric for monitoring [the] amount of circulating virus as home testing increases and disease acuity decreases because of vaccination and treatment."