A Look in the Sewer: Using Wastewater-Based Epidemiology to Track COVID-19
Wastewater-based epidemiology (WBE) is a disease-tracking tool that involves analyzing untreated wastewater for biomarkers. This public health tool serves as an early warning system and provides a timely and cost-effective way to assess the health of communities. A recent article from Yale University showed the SARS-CoV-2 viral signal in wastewater may indicate trends in disease incidence in the contributing sewer service area 7 days before clinical testing of the population.
The SARS-CoV-2 virus that causes COVID 19 is excreted by the body and carried through wastewater to the local sewage treatment plant. Although the SARS-CoV-2 virus is very dilute in wastewater, researchers are still able to detect and measure the viral signal through RNA markers. Researchers are employing qPCR technology commonly used in labs and hospital settings to clinically diagnose individuals to prove that the small quantities of the virus RNA present in untreated sewage can be measured in the complex matrix of wastewater. The data collected can be used to track warnings of potential recurrences of diseases like COVID-19 without testing residents individually.
Even after the COVID-19 crisis subsides, long-term monitoring of wastewater can provide ongoing benefits to communities and decision makers. WBE techniques have been successfully applied to investigate the occurrence of diseases like norovirus, polio and hepatitis A. They have also been used to investigate patterns in other public health characteristics, such as opioid usage and even stress levels in the population.
Teaming up with Dr. Xagoraraki at MSU
Irene Xagoraraki, Ph.D., associate professor of civil and environmental engineering at Michigan State University (MSU), is a pioneer in the field of WBE, and has quickly moved to apply her research to SARS-CoV-2 to mitigate the societal impacts of COVID-19. Dr. Xagoraraki’s own research prior to the current COVID-19 crisis demonstrated that extremely low trends of hepatitis A in the population could be discerned in wastewater.
In March, Dr. Xagoraraki’s team at MSU teamed up with CDM Smith and the Great Lakes Water Authority (GLWA) in Detroit with the goal of rapidly developing a practical method for applying WBE at the community scale. The aim of our research is to provide advanced notice of future trends in COVID-19 disease in the population as a whole, which can help Detroit’s decision makers take targeted action in the event of a resurgence of the disease.
Since March, more than 100 samples have been collected from Detroit’s wastewater flows at three interceptors—downstream endpoints of separate sewer collection networks in the city—and successfully analyzed in Dr. Xagoraraki’s laboratory using the sensitive virus quantification method she has developed. Our research team will be working with Dr. Xagoraraki to correlate the virus signal with the number of COVID-19 cases within the contributing sewer service area.
Our goal is to generate a public health tool that will inform short-term responses to viral threats, long-term disease prevention and be applicable to other viral diseases beyond COVID-19.
Findings in Detroit
Thanks to our firm's internal R&D program we were able to mobilize quickly to apply our skills and connect with other strategic thinkers to help.