Photo Credit: University of Missouri
By Kathleen Berger, Executive Producer of Science & Technology
Collecting samples of wastewater may seem like a dirty job, but somebody has to do it so that Marc Johnson, PhD, at the University of Missouri School of Medicine can track the spread of COVID-19 and its variants in the state.
All that Johnson’s lab needs is human waste to identify genetic material from the virus and its mutations.
“As long as you’re using a toilet, then your waste is going to the wastewater treatment facility, and we can measure it,” said Johnson, professor of molecular microbiology and immunology.
Johnson is a pioneer in this new science for COVID-19 tracking.
“I have the best sort of observation view of anyone in this country,” said Johnson. “I could tell Delta was the real deal long before the CDC decided it was the real deal.”
Partnering with the Missouri Department of Health and Senior Services and the Missouri Department of Natural Resource, Johnson’s lab was first to identify the Delta variant in Missouri nearly a month before the first patient tested positive for it. Then by testing wastewater from communities throughout Missouri, the lab successfully tracked the spread of the Delta variant across the state.
The Sewershed Surveillance Project has a website with a tracking tool for anyone to follow: https://storymaps.arcgis.com/stories/f7f5492486114da6b5d6fdc07f81aacf
Just one positive case in a community can be identified in a sample of wastewater. Johnson estimates he can get a signal of just one case among a thousand to 10,000 people.
“Basing it sort of on knowing where we’ve gotten signal and what the caseload has been,” he said.
Missouri is first to have this level of success with wastewater surveillance. Johnson says that’s because his viral sequencing protocol is different.
“No one else is deciding to use our protocol, but I know that they are all still struggling with theirs,” Johnson explained. “No one else is saying, ‘Oh, let’s do it the way Missouri is doing it.’ They’re all continuing to try and get the whole genome every time.”
Johnson says the way he is doing it quickly identifies variants in a similar way facial recognition technology quickly identifies people.
“We look at a very small piece of the SARS-CoV-2 genome. So it’s kind of like, if you can’t look at the whole person but you want to be able to tell who they are, you would probably look at their face. It’s kind of like that,” he explained.
Johnson is confident he’ll be the first to know when and where a new variant may emerge in Missouri. The new Mu variant is a variant of interest. He’s already identified the presence of Mu in a handful of samples over summer months, but nothing alarming.
“We’re watching for it. I haven’t seen anything scary new yet. Delta is still the cream of the crop. It is really contagious.”