One Way to Monitor a Community's Coronavirus Infections: Test the Sewage

By now we’ve heard plenty about the difficulty of accessing widespread testing for the coronavirus. However, there is another approach for municipalities who want to know the presence and extent of the COVID-19 virus in their community…

Sewage.

Ten counties, coordinated by the East Bay Municipal Utility District, are giving samples of sewage water to researchers at Stanford for testing. The scientists have received samples once a week for about the past two months, and results are expected soon.

The virus begins to show up in feces soon after infection, and according to some studies, well before the development of symptoms. That’s a pretty early warning compared to one given by, say, a diagnostic test.

Eileen White, director of wastewater for East Bay MUD, is spearheading the effort, hoping it will provide information that officials can use.

“We can monitor trends in real time, evaluate community-based presence and infection rates,” said White, “and then prioritize to focus areas and theoretically observe the impacts of shelter-in-place orders.”

East Bay MUD recently secured 1.5 million in anonymous funding to expand and extend the reach of testing. Areas such as Redding, in the northern part of the state, will be included. White sees the need for sampling to last the length of the pandemic, so communities can detect surges or resurgences.

“You can use sewage as the tool,” she said. “You can see if it starts coming up back in the communities as we get into fall, and if you need to go back into shelter-in-place orders.”

It could also provide early warning for health departments to ramp up capacity, she says.

“It’s a great predictive tool for the medical community to know if they need to get ready for surges and patients coming into the hospital.”

Similar sewage monitoring for COVID-19 is happening in Massachusetts, Israel and the Netherlands.

“It doesn’t require sampling a whole bunch of people,” Dr. Angela Rasmussen, associate research scientist at Columbia University, said in an online webinar. “This is exactly the sort of creative innovative approach we need to test at population scale.”