Along with bits of teeth, coins, toys and additional inedible items that get swallowed and come out the other end, traces of disease also can be found in fecal matter, days before people feel sick.
To that end, human waste has become a subject of research in identifying the presence of COVID-19, determining potential outbreaks and tracking trends.
“It’s a very fledgling science; there’s a lot to be learned,” said Rick Johnson, laboratory manager for Colorado Springs Utilities.
The city-owned enterprise is one of 17 wastewater companies participating in a statewide effort to collect and analyze samples of excrement.
Denver, Boulder, Fort Collins and Pueblo are among the communities taking part in the one-year program, which began in June.
Spearheaded by the Colorado Department of Public Health and Environment, the goal is to develop data sets that can help guide public health policy relating to COVID-19, Johnson said.
“The hope is to understand the trends and give the information to local health agencies to have another tool in their arsenal in making decisions.”
This is the first time for Colorado Springs Utilities to be involved with such a research project, Johnson said.
Employees are capturing 50-milliliter and 100-milliliter representative samples of feces twice weekly — about the size of a roll of quarters — and sending the material to Colorado State University in Fort Collins for testing. Metro State University in Denver also is testing specimen for the project.
At the University of Colorado in Boulder, a team of 18 students and microbiologists working under project leader Cresten Mansfeldt, assistant professor of civil, environmental and architectural engineering, last week brought online 23 sewer sampling stations on the campus to capture and evaluate waste from dorms.
Between 40% and 80% of infected people eliminate the SARS-COV-2 virus that causes COVID-19, Mansfeldt said.
Finding the virus in sewage is not a diagnosis but “could identify whether or not there are infections in certain areas of the campus,” he said. The discovery could trigger testing of students in those areas to isolate the virus and prevent it from spreading campuswide.
Emerging infection can be revealed about a week before someone might have symptoms, Mansfeldt said.
“The best thing I see about this tool is that it is specific yet anonymous, and extremely noninvasive to the individual,” Mansfeldt said in an email.
At the sampling stations, a small pump and battery pull wastewater from the sewage system from four to 20 feet below ground into a secure container placed in a cooler. About two gallons is siphoned over 24 hours, he said.
Teams remove samples daily and look for the same type of indicators found in nasal swab collection.
Any virus that a student sheds through waste can be recovered in a sample about 36 hours after it gets flushed down a toilet, Mansfeldt said.
Colorado Springs Utilities’ workers test the 60 million gallons of wastewater that's treated at its two plants all day, every day, to ensure it’s in compliance with numerous government regulations, Johnson said, so adding the new virus collection isn’t much of a burden.
However, it’s been difficult to do composite testing over a 24-hour period and capture a representative sampling, he said.
After two months of gathering samples, results are starting to come in. Figuring out what the data means is another challenge, Johnson said.
What will be interesting, he said, is determining how many asymptomatic people have the virus, since the virus still shows up in their feces.
“It has potential predictive indicators,” Johnson said.
Grant money is paying for labor, shipping and other expenses, he said.
Nationally, some communities have been using private labs to do such testing, which costs $1,200 per sample, Johnson said, an expensive proposition for utilities.
The state’s public health department is developing a public dashboard with results, which will show whether actual confirmed COVID-19 cases are in line with the prevalence of the virus in the community’s wastewater.
“It’s a large-scale collaborative effort and neat to see with all the minds and skills coming together,” Johnson said. “It gives us a chance to make a difference.”
