The highly contagious Delta variant of COVID-19 has been detected in wastewater samples taken at some Kansas City area wastewater treatment facilities, according to tracking by the Missouri Department of Health and Senior Services.
The water is not a danger to the public, officials say, but it is a sign that the variant is taking hold in the area.
The data comes as Missouri earned the dubious honor of having the highest rate of new COVID-19 infections in the United States, racking up a 72% increase over the last two weeks, according to a New York Times analysis. And it comes with new concerns over the rapid spread of this variant.
The latest wastewater testing, from the week of June 7, found levels of the variant at the Atherton and Rock Creek wastewater treatment plants, both in Independence.
It also found the variant in samples taken at treatment plants in Platte City and St. Joseph, north of Kansas City, the state health department’s tracking map showed. The week before, the variant was found in samples from the Atherton plant, and in Liberty, according to the map.
The Delta virus, first detected in India, could soon be the dominant strain in the United States, Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, warned last week.
The variant is becoming more prevalent across Missouri, especially in rural areas. It was found in 27 of 30 locations tested across Missouri the week of June 7.
“Towards mid-to-late February we started seeing the UK virus in sewersheds and saw it start spreading across the state,” said Jeff Wenzel, chief of the Bureau of Environmental Epidemiology for the Missouri Department of Health and Senior Services.
“We’re seeing a similar story with the Delta virus now. A few weeks ago we saw it in one or two sewer systems.”
The trend is enough of a concern that state health officials continue to urge Missourians to get vaccinated against COVID-19. The vaccine rate in both Missouri and Kansas is far below the national average.
Working with the Missouri Department of Natural Resources and the University of Missouri, the state health department began testing wastewater for variants in February. The genetic material from the coronavirus can show up in human waste, providing an early indication of COVID-19 infection in communities.
DHSS posts the findings of the Sewershed Surveillance Project in a map, linked on its website.
“The first week of June, 14 out of 23 facilities contained mutations associated with the Delta variant. The week of June 7th, we are seeing 27 of 30,” said Wenzel. “This is the most locations we have seen, but it is also the most sites we have tested.”
According to the New York Times analysis, 13 of the 25 counties in the country with the highest rates of new COVID-19 cases are in Missouri. Most were in rural areas, although Joplin was also included.
“So what we saw with this India variant, basically it seems to have started in that rural population. Those smaller cities, more rural locations, were the ones where we were more likely to see it,” said Wenzel. “Not that it couldn’t happen in Kansas City or St. Louis. It’s just those were the areas we were testing, those were the areas we were seeing it.”
In Kansas, the state health department teamed up last year with researchers at The University of Kansas and Johnson County officials to study wastewater samples in the county for the presence of COVID-19.
Now, though, “we are not conducting Delta variant testing in wastewater at this time,” said Kristi Zears, spokeswoman for the Kansas Department of Health and Environment. “However, we are exploring it as a future effort and our consultant has reached out to Missouri concerning their operations.”
Kansas ranked 23rd in The Times’ analysis of new cases.
Delta is a ‘moving target’
The wastewater is sampled before it goes through the usual treatment process, “so no one is getting exposed to that water or drinking it,” said Wenzel, answering a question he gets asked often. And, he said, the bits of virus they find in the treatment system are no longer dangerous.
“As it’s passed through that miles of sewer pipe it has become inactive,” he said. “And really, it might have been inactive before it even left your body.
“Especially in Kansas City. It takes a long time for sewage to move from point of entry to the sewage plant. There are some cases that it’s been in there for a few days.”
The department is testing for COVID-19 at 83 facilities, Wenzel said.
“We’re only able to test for variants when the viral load gets to high enough for us to look at,” he said. “We have to have enough there to look for those mutations. So that means we’re not testing every plant every week.
“So unfortunately we’re not able to show you those mutations every week. So it’s kind of a moving target.”
Plants where the viral load increased by 40% or more from the previous week, or increased by 25% or more for the previous two weeks, can sometimes, but not always, predict an increase in the number of COVID-19 cases in that community.
Because the testing looks at a sewer system as a whole, it is impossible to know exactly where in the community the virus is coming from, health officials say.
In early April, testing began at KC Water’s KC Rocky Branch wastewater treatment plant north of the river, Wenzel said, and the detected viral load this week “is one of the higher ones that we’ve seen there,” he said.
“We weren’t testing it at the same time as we were having those huge viral load numbers in November and December, so we don’t have that to look at. So really we’re just looking at those numbers in early April and they’re at or above those levels we were seeing” then.
Delta variant is in 41 states
Testing for variants doesn’t show how much is in the wastewater, Wenzel said.
“That is one of the downfalls of our sewershed testing,” he said. “With the variants, we’re able to see is it there. But we can’t tell you how much is there.
“We’re just able to say we’re seeing that mutation. So we piece the puzzle together to say Delta is there, but we’re not able to tell you a certain percentage is Delta versus something else.”
The Delta variant has been reported in at least 41 states, according to the CDC.
“When these viruses mutate, they do so with some advantage to the virus. In this case, it is more transmissible,” Walensky told “Good Morning America.”
“It’s more transmissible than the Alpha variant, or the U.K. variant, that we have here. We saw that quickly become the dominant strain in a period of one or two months, and I anticipate that is going to be what happens with the Delta strain here.”
Current COVID-19 vaccines work against this strain, Walenksy said, but health officials worry that the virus could mutate to the point where the vaccines won’t work. Potentially, the Delta variant can cause more serious illness and require hospitalization among people who aren’t fully vaccinated.
That’s especially concerning in Missouri, considering how many people aren’t vaccinated yet.
About 44% of Missourians — the same percentage as Kansas — have had at least one shot, according to state health departments, compared to 53% of eligible Americans reported by the CDC.
Missouri posts the map of wastewater testing results both for public health officials and the general public, all of whom have decisions to make when it comes to COVID-19.
“Hopefully, this will encourage people to go out and get their vaccinations and do what they can do to help prevent the spread, get tested, and stay at home if you’re sick,” said Wenzel.