Omicron Variant Discovered in Oklahoma Wastewater

The Omicron variant of the virus that causes COVID-19 was discovered in sewage samples collected in Tulsa on Friday, December 17.

The discovery of the Omicron variant was made through the efforts of a team comprised of scientists, epidemiologists and public health leaders from the University of Oklahoma, OU Health, the Tulsa Health Department and the City of Tulsa and supported by the Pandemic Prevention Institute at the Rockefeller Foundation. People infected with SARS-CoV-2 shed the virus in their waste before they develop symptoms of COVID-19, allowing scientists to provide an early warning of surges and, now, the presence of the new variant.

Since September 2020, the team has been monitoring wastewater drainages in Tulsa, Oklahoma City and, more recently, several smaller cities. Wastewater samples are collected by a team led by Jason Vogel, Ph.D., Grant Graves and Caitlin Miller of the Oklahoma Water Survey at OU and are analyzed by a team of microbiologists led by Bradley Stevenson, Ph.D., Ralph Tanner, Ph.D. and Erin Jeffries of the Department of Microbiology and Plant Biology at OU.

“By collecting wastewater from multiple communities across the state, we have a sampling network that represents more than 1.2 million Oklahomans,” Vogel said. “That has allowed us to sample more than 30 percent of the state’s population and detect the Omicron variant in wastewater as it starts to move into the state.”

“We have seen the concentration of SARS-CoV-2 in wastewater increasing recently, to concentrations higher than we have ever observed. This increase has been driven by COVID-19 caused by the Delta variant. However, the recent detection of the Omicron variant in wastewater means that a significant number of Tulsans are now infected with it. While our data suggests that infections from the Omicron variant are still a fraction of the infections from Delta variant SARS-CoV-2, Omicron is on the rise. Monitoring wastewater will allow us to track its prevalence more quickly and with less effort than patient testing,” Stevenson said.

“The detection of Omicron in Tulsa’s sewage highlights the power of wastewater testing as an early signal and complement to other surveillance approaches. The Rockefeller Foundation and the team at the Pandemic Prevention Institute are proud to support this cutting-edge work,” said Megan Diamond, manager and wastewater lead at The Rockefeller Foundation.

Public health officials reiterated the importance of getting vaccinated or receiving a booster shot and wearing a mask in public indoor settings. Because wastewater analysis predicts the presence of the virus about a week before infections may be reported through human testing, researchers know the Omicron variant is already spreading in the state.

“Although the Delta variant of COVID-19 is still the most dominant variant in Oklahoma currently, Omicron will most likely become the dominant variant in a few weeks or months,” said infectious disease epidemiologist Katrin Kuhn, Ph.D. of the Hudson College of Public Health at the OU Health Sciences Center. “The evidence thus far shows that the Omicron variant is more transmissible than previous variants, so it is important that people get vaccinated if they’re not already, or get the booster if they’re eligible. Vaccinations are very effective at preventing severe illness, hospitalizations and death.”

“It is more important than ever that people who are unvaccinated get vaccinated as soon as possible and those who are fully vaccinated get their booster,” said Tulsa Health Department Executive Director Dr. Bruce Dart. “It’s also important to stay home when sick to prevent the spread of illness. Testing is a great resource to know your COVID-19 status before going around others. Masking indoors where social distancing may be difficult, regardless of vaccination status, is also recommended. The Tulsa Health Department encourages all residents to continue to take a layered prevention approach to stay safe.”

Even though the Omicron variant appears to be more easily transmitted than the Delta variant, early evidence suggests that the symptoms of infection could be milder, Kuhn said. That points toward a classic trajectory for viruses in general, including possibly SARS-CoV-2, the virus that causes COVID-19.

“For viruses to survive in the human population, in time they often evolve to become more transmissible but less lethal in order to keep multiplying,” Kuhn said. “That’s actually good news. Even though we may have to learn to live with COVID-19 indefinitely, a positive scenario is for it to become milder and eventually turn into something like the common cold.”

The characteristics of the Omicron variant also underscore the importance of wastewater surveillance, Kuhn said. Because people infected by Omicron may not experience major symptoms, they may not get tested; therefore, official test results won’t accurately reflect the infection rate.

“If people don’t feel as sick with an Omicron infection as they do with the Delta variant, they may not get tested, but wastewater analysis provides a picture of everyone who is infected whether they have symptoms or not and whether or not they get tested,” she said. “In that respect, it’s actually more important to monitor the wastewater because it gives us a very good indication of how much transmission there is in a community.”