OU Wastewater Surveillance Team to Monitor Long-Term for Foodborne Pathogens, a Global First

With the onset of the COVID-19 pandemic, wastewater surveillance in Oklahoma became an important tool for predicting surges and clusters of infections. Now the same University of Oklahoma-based surveillance team will conduct long-term monitoring for several foodborne pathogens that cause gastrointestinal disease, becoming among the first in the world to routinely monitor wastewater rather than doing it on an episodic basis.

People infected with pathogens shed them in their waste before they ever develop symptoms of disease. For that reason, wastewater surveillance has been especially important during the COVID-19 pandemic, typically predicting surges seven days ahead of when case counts increase. Infectious disease epidemiologist Katrin Kuhn, Ph.D., of the Hudson College of Public Health at the OU Health Sciences Center, said the process will be valuable for the detection of common foodborne pathogens in Oklahoma, which cause illness in thousands of people each year.

“We hope this project will prove that you can use wastewater surveillance to look for various diseases, but also to help in the investigation as outbreaks happen,” Kuhn said. “When we find pathogens that indicate an outbreak, we can launch public health messaging and begin to better understand the dynamics of how diseases are spread and, ultimately, reduce the number of people becoming sick.”

Samples will be taken from sewer sheds in various Oklahoma locations, primarily Oklahoma City, and the team will be looking for evidence of Salmonella, Campylobacter, Norovirus, and a type of E. coli called Shiga toxin-producing E. coli (STEC). They are the four most common foodborne pathogens in Oklahoma and typically cause nausea, vomiting, stomach cramps and diarrhea.

Kuhn sees wastewater surveillance as an important complement to testing for gastrointestinal diseases. People who get sick may recover without medical care or, if they go to the doctor, they may not be tested for foodborne pathogens. Testing, while crucial, often doesn’t tell the whole story of infection rates. Previous studies have shown that for every one diagnosis of a foodborne infection, there are up to 20 more people who are infected but never get a diagnosis, she said.

“We are missing a lot of information when we focus solely on those people who get diagnosed,” Kuhn said. “By doing wastewater surveillance, we get a picture of everyone who is infected whether or not they have symptoms and whether or not they get tested for an infection. We don’t get that with traditional human testing.”

Wastewater surveillance goes back 60 to 70 years when it was first used to monitor for polio, helping public health leaders understand where infections were spreading and to encourage preventive measures in those areas, Kuhn said. Since then, wastewater surveillance has been used to monitor a variety of different diseases, but only for defined periods of time. Kuhn aims for this project to prove the relevance of ongoing monitoring. She also hopes to expand surveillance to rural areas of Oklahoma where people don’t have easy access to medical facilities for testing.

Kuhn is leading the project and working alongside Oklahoma’s wastewater surveillance team, which is comprised of epidemiologists, scientists and public health leaders from the OU Health Sciences Center, OU’s Norman campus, and the Oklahoma City-County Health Department, working in conjunction with the cities where samples are taken. The group received a grant from the Oklahoma City-based Presbyterian Health Foundation to launch the project.

Wastewater samples will be collected by a team led by Jason Vogel, Ph.D., of the OU School of Civil Engineering and Environmental Science and director of the Oklahoma Water Survey at OU. The sampling process that was established for SARS-CoV-2, the virus that causes COVID-19, is easily adaptable to other pathogens, he said.

“The foundation of using wastewater as a surveillance tool for infectious disease in a community is to collect sewage samples that are representative of the broad population in the area,” Vogel said. “Our sampling techniques ensure that we have the best possible samples for our objectives.”

Microbiologist Bradley Stevenson, Ph.D., of the Department of Microbiology and Plant Biology on the Norman campus, will oversee analysis of the wastewater samples. He developed the team’s process for detecting SARS CoV-2 and has a background in studying environmental microbiology.

“The same sample processing that we’ve perfected for SARS-CoV-2 detection can be used to test for other pathogens,” Stevenson said. “Now we are adapting existing clinical assays for these pathogens for use in wastewater.”

The Oklahoma City-County Health Department will host surveillance results and, if outbreaks are discovered, notify the public and remind people to properly cook food, wash their hands, and go to the doctor and get tested when they’re feeling sick. The project is especially timely given the recent outbreak of Salmonella infections across the United States, including Oklahoma.

Phil Maytubby, Chief Operating Officer of the Oklahoma City-County Health Department, said: “This groundbreaking science, which we’re currently using for COVID-19 response, has practical application in the fields of acute disease surveillance and public health emergency preparedness and response. The possibilities are limitless and can provide early warning to our community.”