Sewage Surveillance for Monitoring COVID-19 in Oklahoma Communities

Monitoring sewage as a means of detecting the prevalence of pathogens dates back more than 60 years, when the focus was on the Polio virus. The realization that individuals with COVID-19 could have nearly as many virus particles in their stool as in their nasopharynx prompted many scientists around the world to apply the principles of wastewater-based epidemiology to monitor the prevalence of COVID-19. In the spring of 2020, I helped assemble a collaborative team of scientists with expertise in water sampling, microbial molecular biology, epidemiology, community planning and engagement. We began by monitoring the concentration of SARS-CoV2 in sewage coming from several dormitories on the OU-Norman campus and the City of Norman. This work quickly expanded to include the City of Oklahoma City, Tulsa, Midwest City, and Anadarko, representing over 1.2 million Oklahomans. Since August 2020, we have monitored populations at the building, neighborhood, and municipal level, from as few as 50 to over 500,000 people. Populations associated with college campuses can be transient, with significant fluctuations related to the academic calendar and sporting events. We are using cell phone and WIFI data associated with the OU-Norman campus and the City of Norman to adjust population levels and better understand fluctuations in concentrations of SARS-CoV2 in this sewage. Our data strongly predicts the prevalence of COVID-19 with a lead time of 7 days before positive cases are reported with a high correlation. This correlation between our data and reported cases has dropped significantly since health departments have transitioned from widespread testing to vaccination distribution, leaving sewage surveillance as the only reliable indication of COVID-19 in these populations. Sequencing of the viral genomes from our sewage samples suggests that subsequent waves of SARS-CoV2 infections have been connected to viral variants of concern (e.g., B.1.1.7) becoming more widely distributed. We continue to monitor municipalities for COVID-19 infection levels and the prevalence of various variants of concern, but we are also looking towards the future which we feel should include sewage-based monitoring of COVID-19 and other prominent or persistent respiratory, gastrointestinal, or vector-borne pathogens. The ability of wastewater-based epidemiology to provide an economical and testing-agnostic measure of public health has proven itself during the current pandemic but will likely remain to be a method of choice in the future.

Dr. Bradley Stevenson is an Associate Professor at the University of Oklahoma, in the Department of Microbiology and Plant Biology. Dr. Stevenson earned his B.A. in Microbiology at Miami University in Oxford, OH and his Ph.D. in Microbiology at Michigan State University, where he also was an Agouron Geobiology Postdoctoral Fellow. Brad joined the faculty in the Department of Microbiology and Plant Biology in 2005. His research group studies the role of microbiomes of natural and engineered ecosystems. Dr. Stevenson's research is supported through funding and collaborations with the NASA Exobiology program, the Air Force Research Laboratories (AFRL), the Secretary of Defense Office of Corrosion Protection Technical Corrosion Collaboration program, and several industry partners. Dr. Stevenson's research group is also part of the OU Institute for Natural Products Research and Technologies (INPART). With funding from the National Institutes of Health, his group studies the metabolites from microbial assemblages as a means to better understand interactions between populations and to identify novel antibacterial, antifungal, and anticancer drug candidates.

Since the onset of the COVID-19 pandemic, Dr. Stevenson has drawn upon the expertise of his research group to focus on monitoring COVID-19 in sewage across the OU-Norman campus, several cities and municipalities and other partners. Dr. Stevenson helped form the OU Sewage Surveillance Team, which is a growing collaboration of scientists from the School of Civil Engineering and Environmental Sciences, OK Water Survey, OU Medicine, and the OU Hudson School of Public Health and Environmental Safety. They are currently monitoring over 2 million Oklahomans for COVID-19 and SARS-CoV-2 variants through detection and sequencing of sewage samples at the municipality, neighborhood, and building level.