For 24 hours starting early every Sunday morning, small pipes suck samples from the river of sewage flowing into the South Platte Water Renewal Partners wastewater treatment plant in Englewood for 24 hours.
The tubes deposit the raw sewage into containers inside a box that resembles a mini fridge. Goggled, masked and gloved workers then haul the samples to the plant lab, package it in special vials and overnight it to a lab near Boston.
There it becomes part of a national effort to track the novel coronavirus through poop.
At least two Front Range water treatment entities and one Western Slope county are taking part in this attempt to determine how much of a given population might be infected with coronavirus, if the virus’ spread is increasing or decreasing, and where hotspots of the highly infectious virus might be.
Sewage surveillance, poop tracking, wastewater epidemiology. Call it what you will. It involves looking for and tallying fragments of the virus’ RNA, its genetic material in human waste. It’s a search akin to finding a fingerprint rather than locating an entire body. The numbers of these genetic RNA fragments can be calibrated with population to give an estimate of how many virus carriers there are. The density of the genetic material in specific waste streams can also point to virus hotspots in communities.
Fecal surveillance is like testing an entire city
Looking for the coronavirus in feces has a number of advantages. The virus can be detected in poop within three days of infection. That is days before most people would show signs of having the virus. The RNA levels detected in feces can highlight a problem weeks before there is a discernible outbreak. And it can be done on a population-wide basis, rather than trying to individually test thousands of residents to glean similar information.
“I think it certainly has potential. We are looking at it as something in the overall tool kit for the state,” said John Putnam, director of environmental programs with the Colorado Department of Public Health and Environment.
Putnam said the state, particularly the governor’s Innovation Response Team Task Force for coronavirus, is watching South Platte, the Metro Wastewater Reclamation District, Gunnison County and other Colorado entities that are beginning to jump on the fecal-testing bandwagon. They are considered the models for a potentially more widespread wastewater coronavirus tracking program.
Nationally, the Centers for Disease Control and Prevention, the Environmental Protection Agency and the Department of Homeland Security have already expressed interest in the testing. Currently, about 270 wastewater treatment facilities in 40 states are participating in coronavirus tracking. That tracking now covers about 10% of the U.S. population.
Biobot Analytics, a Somerville, Massachusetts-based nonprofit, is behind much of that testing, including in Colorado. Biobot is rushing to adapt previous fecal monitoring for other pathogens to make it work for the coronavirus pandemic. The coronavirus has thus far mostly evaded any widespread attempts to track its spread through the testing of individuals’ mucus or blood.
Biobot has been promoting wastewater epidemiology to gather population-level insights into human health since it launched a joint research project with the Massachusetts Institute of Technology in 2017. The company is advancing a type of monitoring that is actually not a new thing.
Fecal tracking has been used to look for polio in the sewage in developing countries and in Israel. It has helped catch outbreaks of norovirus, hepatitis A and other disease-causing pathogens around the world. Fecal monitoring has measured illicit drug use in parts of Australia. Opioid epidemics in some areas of the South have been tracked in feces measurements.
Biobot responded to emailed questions about its coronavirus testing with a statement saying that its team “is heads down making sure Biobot is able to reach as many communities as possible as part of their COVID-19 response program.”
Thus, there is no time to answer questions right now, wrote company spokesperson Tenaya Goldsen.
South Platte got the idea from a story in Popular Mechanics
Serendipity brought some of the Colorado entities on board Biobot’s coronavirus fecal monitoring program.
“I read an article about it in Popular Mechanics,” said Pieter Van Ry, director of the South Platte wastewater facility. “I reached out to Biobot to see if we could help, and they sent us sample kits. That was in late March. We have been taking weekly samples since then.”
Andrew Sandstrom, a spokesman for the Gunnison County COVID-19 Task Force, said his county jumped on the sewage testing opportunity after a community member brought it to the task force’s attention.
“We signed up and started taking samples,” Sandstrom said.
So far, the testing hasn’t yielded any quick answers. It has been more successful at raising questions about how the testing will be calibrated going forward.
“The trending is what we see as the value of this whole testing thing,” said Blair Corning, deputy director of environmental programs at South Platte.
He said the two result reports they have received so far from Biobot indicated an increase in virus, but that will become clearer with further test results.
The testing has been more problematic in Gunnison County than it has in metropolitan areas. Sandstrom said heavy spring mountain runoff flows into the wastewater treatment systems at this time of year dilute the sewage and thus the levels of virus.
Another problem is that the population is hard to calculate now in Gunnison County. The pandemic has shut down tourism, so many condominiums and rentals in parts of the county, like Mt. Crested Butte, are sitting empty. Coming up with accurate population numbers to correlate with virus levels in the sewage has been difficult.
“The company is still tweaking how they are going to interpret our data,” Sandstrom said. “We are hopeful that it will get there.”
This week, Biobot will be holding a virtual meeting with all the entities participating in the fecal monitoring in Colorado. Participants say they hope to have more information then.
Corning will be dialed in.
“I think it is so interesting to take wastewater and make analysis from it. Taking one population sample rather than testing 300,000 people (the population in South Platte’s treatment area) – it’s such an interesting deal,” he said. “This should have impacts for other future pandemics and other issues.”