On an early Monday morning, Scott Bitikofer and his team gathered around a manhole across from a dormitory at Rollins College, lifted the heavy cast iron lid and snaked a tube down the shaft toward the sewer line.
Connected to an above-ground container, the tube would draw up wastewater samples in 15 minute intervals for 24 hours. Then three vials of that water sample would be wrapped in an ice pack and shipped to a laboratory in Boston for testing.
The goal: to measure the levels of SARS-CoV-2, the virus that causes COVID-19, in wastewater coming from the two dormitories that are linked to that particular sewage line.
The information can signal the presence of infection among students, almost a week before there are diagnosed cases.
“This is that proverbial canary in a coal mine,” said Bitikofer. “It gives you an early warning. And if you have early actionable information, you can stop the spread when it’s in its infancy and you stand a much better chance of being able to contain [the virus] and keep the school open.”
Rollins is one of several universities and municipalities around the nation to use wastewater testing as one of the measures of tracking the spread of the virus.
The method isn’t new. About six years ago, wastewater testing helped identify a polio outbreak in Israel. And in more recent years, it’s been used to track the opioid crisis.
But the pandemic has brought the field of wastewater epidemiology to the forefront.
“Since [the outbreak] I would say pretty much anybody who works with wastewater around the country has been working on this problem of trying to figure out” how to track the pandemic, said Dr. Marlene Wolfe, a postdoctoral scholar at Stanford University’s Woods Institute for the Environment. “A lot of universities have research labs that have completely shifted over to doing this type of wastewater testing.”
It was early in the pandemic when research showed that the virus that causes COVID-19 was shed in human waste — more specifically, in poop — and genetic bits of it could be identified by analyzing wastewater. The virus has usually fallen apart by time it reaches the sewage lines and is no longer infectious, but its genetic material is enough to prove its presence in the community.
Since then, research in the area has exploded.
Biobot, the company that’s analyzing Rollins’ wastewater samples, has worked with more than 400 locations in 42 states, sampling about 13% of the U.S. population, said Jennings Heusnner, business development associate at Biobot.
“It’s definitely a growing business,” he said.
The science behind the using wastewater to track the pandemic is still evolving. For instance, it’s still too soon to use the information to decide how many people are infected. But researchers say eventually, this kind of testing can help save money by identifying the sources of infection, which can lead to more targeted testing.
The testing can also help identify pockets of transmission that may not be known and help monitor not only colleges, but also vulnerable populations at nursing homes and skilled nursing facilities.
Cities and municipalities can use the information to make policy decisions, such as mask mandates and school openings.
The Centers for Disease Control and Prevention has also created the National Wastewater Surveillance System as “a new public health tool to understand COVID-19 spread in a community.”
“We cannot right now make a link to what is the number of infections and the number of infectious people who are in the area based on the wastewater,” said Wolfe, whose lab is working with 50 wastewater treatment plans across the country. “But because we can quantify the amount of the virus, we can say, well it looks like the trend is increasing or it looks like the trend is decreasing.”
Dr. Susan Singer, vice president of academic affairs and provost at Rollins and a biologist by training, first learned about wastewater testing two years ago and when she discovered that the Boston-based company Biobot was testing wastewater for SARS-CoV-2 virus, she was intrigued.
The process doesn’t replace other mitigation strategies, including diagnostic testing, contact tracing, or a daily self-check app. It’s another layer to tracking and stopping the spread of the virus.
“We do the residence halls because it’s a fairly contained group, and so the data has resolution,” said Singer. “If you start to see a spike, you can relate to how many people may be positive and then go in and test.”
The college began testing the wastewater from its 18 dorms in mid-September, when the school opened.
“[The virus level] in one of our very first samples was higher than we’d like, so we used that to see if it was predictive, and it was. It was one of our residence halls where we ended up with a very small number of cases,” said Singer.
The college has not had a large outbreak so far, said Singer, and the virus level in wastewater from residence halls was “low,” according to the college’s dashboard, which shows the college’s positivity rate at about 7%.
Researchers at University of Florida began conducting their own campus wastewater testing in the summer, choosing 28 different locations that captured the dorms, small graduate family housing complexes, sororities and fraternities.
“The big key here is you’ve got to make sure that you know when you get a signal that you can identify where that signal is coming from,” said Dr. Joe Bisesi, an assistant professor at the Department of Environmental and Global Health at the University of Florida.
The university hasn’t had a large outbreak, and when Bisesi and his team have found a spike in the virus in the wastewater, they’ve found that the cases have already been discovered via screening questionnaires or testing, validating their findings.
They’re planning to conduct more research in the field, naming their approach Gator WATCH (Wastewater Analysis for Tracking Community Health).
“We see a lot of promise in this just beyond COVID. [Wastewater] is almost like the lifeblood of our community. We’re looking at what’s coming out of our entire community… and trying to understand what are the potential implications for health of that community, whether it’s measurements of pathogens or pharmaceuticals or indicators of health,” said Bisesi.
On a larger scale, Miami-Dade County has been testing its wastewater with Biobot since early in the pandemic. The county, which has about 120,000 septic tanks and three large regional wastewater treatment plants, has been using the information as a way to observe how well it predicts the trends in the community, but is yet to make it a data point that results in specific actions of policies.
“The remaining question is whether a methodology for gathering and analyzing this data can be developed in such a way that policymakers in the future can use that data to make decisions sooner, and therefore more effectively than they would otherwise have been able to do,” said Douglas Yoder, former deputy director for operation for Miami-Dade’s Water and Sewer Department and a current policy advisor for the department.
nmiller@orlandosentinel.com.
