South Carolina’s slowly falling COVID-19 case counts — which have dipped since a holiday-related spike in January — are showing up in sewage, too. 

For months, University of South Carolina researcher Sean Norman has been testing samples of untreated sewage at 10 sites around the state for the RNA of coronavirus. The data has helped to catch spikes in disease across the population early. 

Now, Norman is seeing declines in prevalence similar to those in testing results, as surging case numbers from in-person gatherings over the holidays wane.