Dan Moser, November 10, 2023
Wastewater-based epidemiology key to tracking disease
The story of John Snow and the Broad Street pump is a familiar one to public health scientists: The physician tracked the spread of cholera in a London neighborhood in 1854 to a single public pump handle, helping give birth to modern epidemiology.
That principle was reborn during the COVID-19 pandemic and is continuing even after its fade in tracking the community spread of other diseases, said Shannon Bartelt-Hunt, University of Nebraska-Lincoln professor of civil and environmental engineering.
Bartelt-Hunt discussed the reemergence of Snow’s groundbreaking findings in what’s now called wastewater-based epidemiology during her Nebraska Lecture on Thursday.
Although the technology and circumstances are very different, what Snow’s and current researchers’ work have in common is an understanding of the connection between environmental infrastructure and public health, said Bartelt-Hunt, Donald R. Voelte Jr. and Nancy A. Keegan Chair of Engineering. This information could play a key role in helping public health officials better allocate resources for a variety of diseases, from potential future pandemics to seasonal influenza.
During the pandemic, a research team led by Bartelt-Hunt found that samples of wastewater from sewer systems provided key information about the prevalence of COVID-19 in a community. Working with partners including the University of Nebraska Medical Center, the Nebraska Department of Health and Human Services and public utilities, UNL researchers established the Nebraska Wastewater Surveillance System, which now covers about 70% of Nebraska’s population with twice-weekly samplings.
“The idea here for us as engineers who design and utilize infrastructure for our wastewater is that we can collect information, collect samples, from our existing wastewater infrastructure that gives us information about a community’s health,” Bartelt-Hunt said.
Samples detect the presence of chemical and biological analytes excreted in human waste, including viruses, illicit drugs, antimicrobial resistance, emerging infections and toxins. During the height of the COVID-19 pandemic, researchers found that the virus’s prevalence in community wastewater tracked closely with hospitalization numbers, meaning such testing could be used to help public health officials allocate critical healthcare resources.
“We found that wastewater-based epidemiology can really complement other kinds of health monitoring,” Bartelt-Hunt said. It’s not a replacement for individual testing but it provides a broader look at a community’s health.
“We have this wonderful engineering infrastructure in place in all of our communities — our sewer systems. … We don’t often think about what’s happening in those pipes that are running under our feet. But engineers can collaborate with our public health practitioners and utilize information that’s in our wastewater to improve our community health.”
During her lecture, Bartelt-Hunt also discussed the role of emerging contaminants in our water systems, such as microplastics and antimicrobials. Antimicrobials for both livestock and humans can end up in water systems and potentially cause resistance to the drugs and other health concerns.
Her research team studied the presence of antimicrobials in two Nebraska watersheds – the urban-dominated Elkhorn River watershed and the more rural Shell Creek watershed. They found both watersheds had troubling levels of antimicrobials, with 31 detected in the water, six of those significant to humans. The Elkhorn watershed had the highest concentrations, while Shell Creek’s was seasonably variable with the highest concentrations in the fall.
The findings underline the importance of the Nebraska One Health principles, a UNL initiative that recognizes human health is closely connected to the health of animals and the shared environment.
Plastics are an emerging contaminant of water; in some cases, they are included in personal care products and in other instances, they are improperly disposed of. Increasingly, microplastics are found in the environment and in the human body.
Microplastics can contribute to a variety of health concerns, affecting immunity, metabolism, breathing, reproduction and more.
Research on a Nebraska crop field found microplastics in runoff from both plots treated with biosolids and from control plots that weren’t treated.
“They’re at very, very low levels, but they can still have an impact,” Bartelt-Hunt said.
“Identifying their occurrence and sources is the first step toward designing remediation or prevention strategies,” she added.
Nebraska Lectures: The Chancellor’s Distinguished Speaker Series are offered once a semester, sponsored by the Office of Research and Economic Development, the Office of the Chancellor and the Research Council, in collaboration with the Osher Lifelong Learning Institute. The Nebraska Lectures bring together the university community with the greater community in Lincoln and beyond to celebrate the intellectual life of the university and showcase faculty excellence in research and creative activity.