The Detroit Water and Sewerage Department and Michigan State University in East Lansing today announced they have evolved a virus research project to study the COVID-19 outbreak with funding from the Great Lakes Water Authority. The original research project began in November 2017 to determine whether viruses can be detected in the city’s sewer collection system.
The results of the project could lead to another mechanism for public health agencies to predict virus outbreaks.
The MSU study’s findings show that viruses, including coronaviruses, can be detected in untreated sewage, and when the data is joined with health care data, it can be used to further trace outbreaks.
“This project has significant implications for providing an advance notice signal of disease incidence in the community,” says John Norton, director of energy research and innovation at the authority, which is offering technical and financial support.
“The various use case scenarios we are developing for the virus data found in the environment will have short, medium, and long-term uses. Short-term use may be to provide information regarding immediate response activities and regulations, while a medium-term use may be to help guide detection of infected people, and long-term uses concern general epidemiological work regarding diseases in general.”
The researchers took the data from the sewage samples and looked at county health data for the same timeframe, discovering that viruses were apparent in the sewer collection system about one-two weeks prior to seeing increases in reported data at health departments for those same viruses.
The study is being led by Irene Xagoraraki, associate professor of environmental engineering at MSU. She received a two-year National Science Foundation grant in 2017 called “A Wastewater-Based-Epidemiology System for Early Detection of Viral Outbreaks in Detroit MI.” She then received a two-year grant from the Great Lakes Water Authority called “SARS-CoV-2 in Detroit: Surveillance and Prediction,” which started in April.
The team is focusing on community composite sampling and analysis. It is a wastewater-based-epidemiology method directly applicable to urban metropolitan areas with centralized wastewater collection.
“Our approach has the potential to provide warnings earlier than traditional systems focused on clinical diagnostics – rapid or not – which are inherently limited to an after analysis of an outbreak,” says Xagoraraki. “Our approach goes above and beyond simple surveillance of wastewater.”
Two models were developed. The first, the Viral Identification Model, determines diversity and genetic makeup of viral infections in a certain population. The second, the Viral Prediction Model, provides early detection of fluctuations of specific viral diseases, such as hepatitis, COVID-19, and others in certain geographical areas over time.
During the National Science Foundation grant, untreated wastewater samples were collected from November 2017-February 2018 to evaluate the diversity of human viral pathogens from the Detroit population. In the Viral-ID model, samples were collected, concentrated, and purified to allow for analysis that detected the presence of enteric, respiratory, bloodborne, and vector-borne viral-related genomic sequences. The measured viral signatures were related to clinically important diseases reported within the study area during the sampling year. Viral species were confirmed with qPCR analysis that measures unique genetic regions related to specific viruses.
To test the Viral-PD model, the concentration of hepatitis A in wastewater, along with other parameters, were correlated with clinical data. Increases in hepatitis A incidence in the surrounding community were revealed in wastewater about seven-nine days before symptomatic cases were reported to health care facilities.
For the work recently funded by the authority, team members from its Water Resource Recovery Facility are collecting samples weekly and providing them to Xagoraraki so she and her team can quantify concentrations of beta coronavirus in wastewater. The team will also determine diversity of human viruses, such as ssRNA coronaviruses, in wastewater with sequencing followed by metagenomic analysis.
To estimate contributing population fluctuations, the MSU team is quantifying concentrations of biomarkers and metabolites in wastewater. To estimate virus detection times in the city’s sewer collection system, hydrological and other network data are analyzed and modeled.
Historic data and data on COVID-19 and other beta-coronavirus disease characteristics, such as incubation times, shedding rates, and duration of shedding, are collected and modeled for estimation of delays between measured viral concentrations in wastewater and demonstration of disease symptoms. Clinical disease records will be used to determine correlations and validate predictions. The developed models are expected to describe patterns of endemic disease, identify potential new viruses, and predict hot spots (counties) and critical moments (weeks), for the onset of spread of outbreaks prior to full-blown demonstration of disease in clinical settings.
“The method we are using is at a research level at this point, and multiple steps need to be followed to make it user-friendly for utilities around the country,” Xagoraraki says. “Partnering with DWSD and GLWA, which operates the largest single site wastewater treatment plant North America, is crucial for the development of this method. If it can be done here with this massive system and show predictive results, it can be done in other smaller communities as well.”
The Detroit Water and Sewerage Department and the authority have committed staff resources to provide access to the sewer collection system and share system data with regard to sewage volumes, collection locations, and other factors.
The city emphasized that once sewage enters the city’s collection pipe, it is not encountered by the general public. Most basement backups are either stormwater or the household’s own untreated sewage. The city’s treatment process uses chlorine to kill viruses in sewage at the Water Resource Recovery Facility in southwest Detroit, which is operated by the authority.
The Detroit Water and Sewerage Department serves more than 230,000 accounts that include a residential population of nearly 700,000. Its water network consists of more than 2,700 miles of water main and nearly 3,000 miles of sewer collection piping within the city of Detroit.
The Great Lakes Water Authority offers drinking water services to nearly 40 percent of Michigan’s population as well as wastewater services to nearly 30 percent.