A team of scientists working out of a Southampton laboratory are working on a way to help determine the level of COVID-19 infections in the population by testing the waste water from septic systems and sewage treatment plants.
Since March, scientists from Stony Brook University have been taking samples from wastewater at the sewage treatment plants in Bergen Point, Patchogue and Riverhead. They now plan to start sampling the untreated waste from the dormitory buildings at the Stony Brook campus to help spotlight potentially unidentified rises in infection rates among students who may not have symptoms.
The approach, known as wastewater epidemiology, is not a new one. It has been used for years to survey various characteristics of populations of people, from drug and alcohol use to diet and general health trends. And it’s been used in the past to trace infectious microbes.
So when the COVID-19 pandemic sweapt across the world in the spring, scientists quickly began looking at waste. European scientists were able to use the sampling method to sound the alarm that the coronavirus was apparently spreading in some communities at rates above what lagging testing and the high percentage asymptomatic carriers were revealing.
“Everybody that is infected sheds the virus in their feces, including people who are asymptomatic and people who are in the first days of infection and have yet to develop symptoms, so it can be an early warning sign,” said Dr. Christopher Gobler, one of the Stony Brook professors leading the research. “We have a few sites we’ve been sampling since the spring that have shown what you would expect: In April when the community infection rates were the highest, we were detecting the virus and in June, when the infection rates dropped, we weren’t detecting it.”
Thus far, the sampling the scientists have done has been experimental and focused on broad populations — the Bergen Point sewage treatment plant services the largest sewer district in Suffolk County — but this fall Stony Brook will begin applying the method to keeping tabs on whether its students are spreading the bug to each other.
“By tracking that, if we do see an uptick, we could have the campus move to testing everybody to get a sense of where things are,” Dr. Gobler said. The effort will soon narrow the focus to individual dormitory buildings.
But the sampling at this point is still only revealing general trends in a population. Another Stony Brook researcher, Dr. Arjun Venkatesan, is working on changing that. By looking at some other chemical indicators along with the virus, he is hoping to use the samples to get an even more detailed picture of how the virus has spread, perhaps down to being able to measure the number of people in a population who are carrying it — which no scientists anywhere have yet been able to do.
“When we first started this, it was just an idea,” Dr. Gobler said. “In the months since then, we’ve developed the techniques and are now transitioning to a new approach … analyzing samples as we collect them. We should soon be able to say there wasn’t any virus detected last week, but it is detectable this week and it’s even higher the next week so we’ll be able to show that we have an expanding outbreak.”