If the presence of the coronavirus (such as viral genetic material) can be detected in sewage, this could inform measures to contain the virus even when people are asymptomatic and unable to access testing kits.

“One of the key areas we’re exploring is whether we can detect this new virus, SARS-CoV-2, in a community’s wastewater before it’s known to be circulating there,” said Professor Krista Wigginton, the project leader at Michigan. “The case numbers we’re seeing reported in the US and lots of other places are dependent on how many test kits we have, so the curve displaying a number of cases is more of a curve of test kit availability in a community. What we see in wastewater may look totally different.”

While this method would not give precise numbers of cases, it would allow for estimates which do not rely on individual testing – with the possibility of much faster detection in local surges – and which are less prone to measurement bias.