Sewage testing for COVID-19 at 'very high plateau' in Tulsa with 'optimistic' signs for decrease soon

Sewage surveillance suggests the spread of the omicron variant in Tulsa remains at "a very high plateau," which experts don't expect to be reflected in weekly county data the state will release Wednesday.

Bruce Dart, the Tulsa Health Department's executive director, said newly reported cases last week remained near record levels here and that he believes the latest case counts will be artificially low because the recent winter storm negatively affected testing sites.

The fact that positive at-home tests are not reported to state officials also means case counts don't reflect the actual number of people who are currently infected.

Dr. Katrin Kuhn, an OU Health infectious disease epidemiologist, said sampling wastewater in municipalities reflects "real community transmission levels" because it isn't beholden to fluctuations in human testing trends — such as inclement weather prompting less testing.

"We have for the past couple of weeks now been at a very high plateau (in Tulsa)," Kuhn said. "I'm also slightly optimistic to report that we are seeing signs of what appears to be a decrease in concentration."

University of Oklahoma researchers in partnership with local officials for a year and a half have sampled wastewater in Oklahoma to monitor for COVID-19 variants and levels of disease spread among municipalities.

Kuhn, who spoke Tuesday during a Tulsa Health Department media briefing on COVID-19, said COVID's omicron variant has resulted in some of the highest concentrations of the virus in sewage the team has found so far in its monitoring.

Dr. Jason Vogel, director of the Oklahoma Water Survey at OU, noted that Tulsa has been about seven to 10 days behind Oklahoma City as far as sewage testing trends go during the omicron wave.

Vogel said Oklahoma City has shown a "sharp drop off" in the past several days that Tulsa hasn't exhibited. He said Tulsa's most recent sampling took place a little more than a week ago.

"We haven't seen that sharp drop off in Tulsa, but if it reflects Oklahoma City, … I'd expect we might be seeing that in Tulsa, as well," Vogel said.

The wastewater surveillance dashboards are available online at sewagesurveillance.net or THD's website at tulsa-health.org on its COVID-19 data page.

Dart noted that while COVID hospitalizations have declined in Tulsa County recently, they remain "very high."

The recent three-day average of 436 COVID inpatients in Tulsa County hospitals was down 13% from 504 a day earlier and 20% below the record 548 on Jan. 29. The most recent low was 119, reported Nov. 9 before a nearly three-month-long increase.

Dart added that two Tulsa hospital systems had applied for assistance from military medical personnel through a federal effort because they "absolutely" needed help.

An official confirmed that Saint Francis Health System had made an application.

"In late January, as the health system was experiencing record COVID-19 inpatient admissions, an application was submitted for federal support in the form of additional clinical staff — specifically nursing staff and respiratory therapists," Dr. Mark Frost, Saint Francis chief medical officer, said in a prepared statement. "At this time, we are still awaiting response to our request."

Hillcrest HealthCare System said it also had applied for the assistance in mid-January, though "it was determined" that the aid would go elsewhere in Oklahoma.

Two Oklahoma City hospital systems were granted assistance through the program.

THD's COVID-19 ZIP code map for the third consecutive week was entirely dark red on Feb. 2 for  "extreme severe" risk — the worst category and one added by the agency in December 2020 after its initial rollout in September 2020 because of how bad the spread had become.

Ellen Niemitalo, a registered nurse and the Tulsa Health Department's clinic services manager, said that while prior COVID infections can offer some immunity, the safest and most effective protection is through vaccination.

Niemitalo said the vast majority of COVID hospitalizations happen to people who are unvaccinated or not up to date with a booster shot.

Federal data show that 60.0% of Tulsa County's population is fully vaccinated, or about 64.5% of the population who is eligible to be vaccinated — ages 5 and older. Of those who are fully vaccinated, 36.9%, or 39.9% who are ages 18 and older, have received a booster shot.

Niemitalo noted that the Food and Drug Administration and the Centers for Disease Control and Prevention have granted full approval to Moderna's vaccine, called Spikevax.

She noted that that now makes two vaccines that are fully approved, with the other being Comirnaty by Pfizer.

Pfizer has requested emergency-use authorization for its vaccination in ages 6 months to 4 years old. Niemitalo said that would be the same formula but a smaller dose than that used in other age groups.

She said that request is set to be discussed Feb. 15 by an FDA advisory committee.