We can measure coronavirus's spread by looking at people's poop

Municipal wastewater treatments plants are actually ideal testing locations

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Overhead image of the Wastewater Clarifiers at the Kailua Regional Wastewater Treatment Plant in Hawaii

Roen Wainscoat on Wikimedia Commons 

Many scientists are following the same rules of social isolation as everyone else. University labs around the world have closed, and we are pivoting to working from home, delivering lectures, supervising students online, and putting our research on ice for now.

Other scientists have completely turned their research programs around to start contributing to the fight against COVID-19. This includes heroic efforts to develop new screens for infection, new antibody assays, and rapid new blood tests. A very different kind of project has been started in many cities, including my adopted home of Stockholm, Sweden.

Researchers around the world now believe that, because most infected individuals shed the virus that causes COVID-19 (SARS-CoV-2) in their feces, it is possible to detect the virus in sewage (wastewater) and thereby track its spread through a city. 

Wastewater treatment plants are the ideal testing site, as they typically serve one municipality where the citizens are also served by the same healthcare centers. The virus can be detected even at low levels, suggesting that wastewater testing could be a powerful surveillance tool to monitor circulation of the virus in a local area, and perhaps give an early warning of a resurgence in cases. 

Projects are ongoing in the Netherlands at the KWR Water Research Institute, in Stockholm at the Science for Life Laboratory and the Royal Institute of Technology, and at institutes in Spain and Turkey, and there is growing global interest in the results.

These efforts will complement the ongoing work to roll out antibody testing that will tell local authorities roughly what proportion of their citizens have been infected without showing symptoms – knowledge that might let some people start returning to work earlier than anticipated.