Meet the Minnesota scientists trying to track COVID-19 spread — through sewage

A person wearing a mask in a science lab.
Glenn Simmons Jr., an assistant professor at the University of Minnesota Medical School in Duluth, is one of two researchers studying the presence of the new coronavirus in raw wastewater in Minnesota communities.
Courtesy of University of Minnesota Medical School

Two University of Minnesota researchers are aiming to track the spread of COVID-19 in the state — through human waste.

Glenn Simmons Jr. and Richard Melvin, both assistant professors at the U of M Medical School’s Duluth campus, teamed up for the study. They’ve also enlisted the help of almost two dozen communities around Minnesota to collect samples of untreated wastewater.

Simmons and Melvin hope to trace the virus' spread across Minnesota in a way health officials aren't able to with in-person testing. They suspect that, in many communities, the virus may be more widespread than the confirmed case numbers suggest.

"We've decided that one of the easiest ways to do that would be to noninvasively kind of scan the population for the presence of the virus,” Simmons said. “And one easy way of doing that would be to look at the wastewater."

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Simmons and Melvin were familiar with research dating back to the 2002 SARS outbreak that showed the virus was showing up in human waste. Earlier this year, scientists in the Netherlands detected traces of the new coronavirus in wastewater.

The pair decided to adapt that research to Minnesota, focusing particularly on rural communities that may not have the same access to COVID-19 testing as larger metro areas.

"We're able to give them information hopefully that will allow them to change their strategies if necessary, or know that their strategies are working,” Simmons said. “So, they’re not just kind of sitting in that black box, just waiting for things to happen.”

The researchers enlisted the help of the Minnesota Environmental Science and Economic Review Board, a joint powers organization of 50 communities with wastewater treatment systems. As of last week, 18 had agreed to participate, including Rochester, Moorhead and Duluth.

Cities do regularly test their own wastewater. But often, they are monitoring wastewater after it’s passed through the treatment plant, which is designed to remove pathogens such as viruses before it’s discharged into a lake or river. 

Simmons and Melvin are analyzing sewage before it's treated. They'll analyze it to detect genetic material from COVID-19, then use a process called polymerase chain reaction to measure how much of the virus was present.

Melvin said the study is similar to a fossil dig: It can tell the scientists what’s happened in a community in the recent past, and give a warning sign of what’s about to come. What they don't know yet is how that relates to actual levels of infection in a community, he said.

Because the virus has been detected in wastewater even before a disease outbreak in other studies, a positive detection can serve as a warning sign to health officials — and the public, Melvin said.

"We don't want to make it so that it's a scary thing,” he said. “We want to make it an awareness … just how careful do we need to be? Well, it's in our wastewater. It's here.”

The pair say they plan to collect and analyze data over the next few months, then share it with the Minnesota Department of Health and the communities involved. They plan to continue their study through the fall or possibly longer to track changes in virus levels over time.

Simmons said the data they collect should be useful to health officials, because a person in the early stages of COVID-19 may not have symptoms, but actually is infectious and releasing a lot of virus.

"If, God forbid, they're moving around like normal, not knowing that they're infected, they're actually spreading it,” he said. “So we, with this technique, potentially could be able to help track those things before they become full-blown."

Simmons said Minnesota is one of the only universities in the country monitoring wastewater for COVID-19 on such a broad scale. He said their research will support the university's efforts to increase COVID-19 testing in Minnesota.

COVID-19 in Minnesota