https://www.pilotonline.com/news/health/vp-nw-coronavirus-hrsd-wastewater-20200809-jjh74mw3snabfbrg5ebio2ctri-story.html

A week before the Virginia Department of Health reported a spike in coronavirus cases coming from Hampton Roads at the beginning of the summer, the increase was being detected not through nose swabs, but in our pipes and sewers.

Jim Pletl, the water quality director at the Hampton Roads Sanitation District, saw genetic material from the virus surge in the wastewater being produced by hundreds of thousands of Virginians when he analyzed samples from the utility company’s nine plants. As he plotted his data over the health department’s data, he saw pretty close similarities, although there was a delay.

“We found the lag time between the time we start to see signals in the wastewater and the time the clinical data starts to change is at least a week,” he said.

The process is called wastewater epidemiology. It’s a way to detect the virus’s presence pretty soon after people flush the toilet, instead of waiting for them to get tested and get their results back, which can take several days. While SARS-CoV-2 — it’s official scientific name — is primarily thought of as a respiratory virus, scientists have found that it can affect the digestive system, and the virus’s genetic material has been detected in stool specimens even before people showed symptoms.