By Kathleen Berger, Executive Producer for Science & Technology
The surge of Omicron cases in Missouri is documented through testing done in a University of Missouri School of Medicine laboratory in Columbia, Missouri. And the Mizzou lab doesn’t need consent from anyone who is infected or not.
“It starts with the toilet,” said Marc Johnson, PhD, professor of molecular microbiology and immunology at the University of Missouri School of Medicine. “People do their business and then they flush, which goes down the tubes and eventually ends up at a wastewater treatment facility. Depending on the city, it might take a few hours or even longer for it to get there, but it mixes pretty well during the process. But eventually it gets to the wastewater treatment plant. At the wastewater treatment plant, as the influent is coming in, there is what we call an autosampler that takes a sample every half hour for a 24-hour period and gets mixed together. Samples of those are what gets sent to my lab for analysis.”
Marc Johnson’s lab collects about 200 samples every week from wastewater treatment facilities across the state.
“We remove everything big so we only have the small things, like viral particles, and then we extract the RNA which is the genome of SARS-CoV-2.”
From this extraction and identification process, Johnson’s lab tracks the spread of Omicron.
“The very first place we detected it (Omicron) was in the northwest – Kansas City and St. Joseph. But within a week, it had also spread out and filled in the I-70 belt. So by the second week, this was already a week before Christmas, we were detecting it in many of the St. Louis sewersheds, many of the Kansas City sewersheds, and many of the sewersheds between them – either on I-70 or close to it,” explained Johnson. “St. Louis and Kansas City really went the fastest. By just before Christmas, it had largely filled out the sewersheds by the beginning of January and has basically gotten everywhere. The last time we tested, I know every one of them had Omicron and a lot of them are to the point where that is the only thing we’re detecting.”
Johnson has been keeping watch over COVID-19 in Missouri since early in the pandemic. That’s when his lab partnered with the Missouri Department of Health and Senior Services and the Missouri Department of Natural Resources to track COVID-19 and its variants in the state. It’s called the Sewershed Surveillance Project, which has a website with tracking tools for anyone to follow: https://storymaps.arcgis.com/stories/f7f5492486114da6b5d6fdc07f81aacf
As of Friday January 21, 2022, Johnson said the wastewater test results from samples in the St. Louis region showed levels of Omicron in wastewater “cresting”, indicating the surge reached its peak in mid-January. Johnson said wastewater testing is reliable, having the ability to identify few cases among thousands of people.
“One in 1,000 and maybe one in 10,000 is the range we think that we can detect it. In some facilities we were pretty sure we’ve detected it from a single person, especially with the smaller sewersheds.”
As a scientist who is studying COVID-19 and its variants very closely, Johnson said the speed of Omicron in Missouri is interesting to him. He said it’s a lot like Delta.
“In terms of how fast they swept the state, there wasn’t that much difference between Delta and Omicron. Delta – within three or four weeks had taken over the state. I will say that the spikes have been higher with Omicron,” said Johnson. “With both Delta and Omicron, once we see them move in, we see a spike in the amount of RNA and we see a spike in the number of cases. But I will say with Omicron, that (spike) seems definitely higher. But how fast it got through the state was fairly similar.”
Johnson advised that Omicron is not a variant to be messed with.
“And this notion that this is a milder version of the virus is largely misunderstood. The average disease is milder. That’s because the average person that’s infected has preexisting immunity. It’s really not entirely clear yet whether this (Omicron) is truly milder than Delta. In an apples to apples comparison, meaning if you’re unvaccinated and get infected with Omicron, it’s not really clear that it’s that much milder than Delta. If you are unvaccinated and you have not been infected at this point, you need to be really, really careful because the chances of you getting infected anywhere you go are very high – much higher now than at any point in the pandemic.”
