“The concept behind WBE is that the concentration of specific microorganisms and/or chemicals in sewage is a reflection of the total inputs of these constituents from a given community,” writes Pepper. “For SARS-CoV-2 and wastewater treatment plants, the concentration of coronavirus in the sewage is a reflection of the total virus load resulting from members of the community served by the plant. Critically important is the fact that the total virus load reflects viruses shed by infected individuals with symptoms, as well as infected individuals who are asymptomatic. Thus, assaying the sewage for the virus monitors a given community with one test, and answers the question: ‘Is the virus currently present in the community?’ Previous studies with poliovirus indicate that as few as one infected person in 10,000 can be detected by WBE.”
Pepper adds that WBE provides quantitative data from multiple samples at a single WWTP over time, determining if the pandemic is increasing or decreasing. “Correlation of sewage concentrations of virus (gene copy) with the number of cases and deaths allows for future prediction of infection rates,” he says. Results of WBE analysis can help determine whether or not a community could/should return to work, evaluate the success (or lack thereof) of interventions such as social distancing, and compare the effects of different secondary treatment processes on virus removal.
Syracuse University (SU) in Syracuse, New York announced plans to use WBE to routinely test sewage leaving each residence hall when the university reopens in the fall. According to an article in Syracuse.com, the testing can “spot signs of the virus before students even become sick. If the testing finds a sudden spike of virus in a dorm’s sewage, SU can start testing students in that building to get a jump on a potential outbreak.” SU Professor David Larsen, who is leading the testing project, said “a person can be infected and start shedding the virus through their intestines up to a week before showing symptoms.” SU has 19 dorms that can house nearly 6,000 students.