As other states have seen their COVID-19 cases start to decline, marking a slowing of the omicron surge, Oklahoma may be nearing its peak.
Concentrations of the virus in sewage being monitored in several cities in Oklahoma have begun to plateau, though they’re still at very high levels, said Dr. Katrin Kuhn, a researcher with the University of Oklahoma's College of Public Health who is part of a team of scientists monitoring wastewater in Oklahoma.
“If we have two or three weeks of consistent readings that show a decrease, then we (will be) confident that the peak has been reached,” she said. “We're not seeing that at the minute, because the concentrations remain very high.”
During the pandemic, wastewater monitoring has allowed scientists to give public health leaders an early look at how COVID-19 is spreading in their communities, without relying on people to get tested or even develop symptoms.
With omicron and other variants that have caused case surges, wastewater concentration has "correlated very well with the increases in reported cases,” Kuhn said.
A few days before Christmas, the researchers said they were seeing the highest-ever concentrations of the virus in wastewater in Oklahoma in the cities they were monitoring, including Tulsa, Oklahoma City and some smaller municipalities.
The levels climbed even higher after that, Kuhn said.
“About two weeks ago, we had the highest readings that we've ever had in any of our localities,” she said. “We were also a little bit surprised, because we didn't really expect it to go much higher than it was already. But … you have to expect the worst sometimes with this disease.”
The omicron surge of COVID-19 in Oklahoma has led to an unprecedented number of infections. More cases have been recorded this month than any other month in the pandemic so far, and those numbers are almost certainly an undercount since they don’t include at-home testing.
Hospitals, too, are feeling the strain — Wednesday’s three-day average of 1,970 hospitalizations statewide is only a few dozen patients away from the state’s all time high of 1,994 in January 2021. But health care workers are handling this surge facing worse staff shortages than before.
In previous surges, a rise in concentrations of the virus in wastewater was about a week ahead of increases in case counts. Researchers are still working to learn how much of an early warning wastewater can give them with the omicron variant.
In a few more weeks, researchers will have enough data to know how many days ahead sewage surveillance is compared to case counts, Kuhn said.
“I would expect, given the different symptoms that people have now with omicron infections, that we will also see a different time lag,” she said.
There are some other signs that Oklahoma could be nearing its peak, Dr. Dale Bratzler, chief COVID officer for the University of Oklahoma, said Wednesday.
First, positivity rates are declining, Bratzler said, citing data from MyHealth Access Network.
“We're very early, but that's often an early sign that you're getting past the peak, when the percentage of people who test positive starts coming down,” he said.
In the OU Health system, officials have also noted decreasing numbers of health care workers in isolation or quarantine with the virus, he said.
“And then, of course, the case numbers themselves: the seven-day rolling average has come down a little bit and the trend line is not as steep as it was,” Bratzler said.
Bratzler said those are each encouraging signs that “maybe we’re starting to see the end of the surge.”
This article originally appeared on Oklahoman: When will COVID-19 cases peak in Oklahoma? Here’s what sewage shows