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Your poop may soon serve as an early warning system for Colorado coronavirus outbreaks

Why the attention to the sewage? A Utah city spotted a spike in coronavirus a week before it showed up in tests. That knowledge could allow communities to act to slow the spread of COVID-19.

Peter West, operator at South Platte Water Renewal Partners stands atop a clarifier where he takes his sludge judge to measure solids at the bottom of the settling tank on May 12, 2020. The South Platte Water Renewal Partners are participating in a sewage study in an attempt to determine how much of the population is infected with the coronavirus. The utility serves Englewood, Littleton and 21 smaller sewage systems. (John Leyba, Special to The Colorado Sun)
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Toilets from Fort Collins to Colorado Springs will soon become important tools in Colorado’s efforts to establish an early warning system for the novel coronavirus.

The state of Colorado has committed half a million dollars in federal COVID-19 relief funds for a year-long pilot program to test sewage. The testing will pinpoint COVID-19-carrying genetic fragments in the poop that goes into at least 11 Front Range wastewater treatment facilities. The study will be carried out under the auspices of the Colorado Department of Public Health and Environment with Colorado State University and Metropolitan State University conducting laboratory testing of the sewage.

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“The real exciting part about this technology is the ability to get an early warning before we can get (individual viral or antibody) test results back. We will be able to see an increase or a decrease,” said John Putnam, the director of environmental programs for the state health department.

Sewage is a valuable testing tool because humans shed the novel coronavirus in poop within a day or two of being infected — well before symptoms usually appear at five to 14 days.

Carol Wilusz, the molecular biologist who will be leading the sewage testing at CSU, said results should be extracted from the sewage and available within 48 hours of the sample collection. That will make it possible to quickly nail down areas where more people are becoming infected. That could trigger social distancing mandates and allow hospitals to prepare for an influx of patients if needed. Once a vaccine is available, the sewage testing could pick up on any outbreaks so they can be squelched before they spread.

MORE: Colorado sewage treatment plants are examining your poop for coronavirus clues. Seriously.

The actual testing will work like this: samples of influent that comes from toilets into wastewater treatment plants will be dipped out of the sewage stream twice a week from each treatment plant. The samples will be delivered to laboratories where fragments of RNA infected with COVID-19 can be counted on a sensitive machine called a digital droplet PCR. Numbers from the digital droplet CPR will then be calibrated with population numbers to determine virus levels.

Wilusz said CSU is ready for this role in tracking COVID-19. The digital droplet machine had already been in use at CSU for five years. And CSU has already been working in partnership with GT Molecular, a Fort Collins business that had been doing molecular detection technology for cancer research and for harmful pathogen detection, as well as individual COVID-19 testing before it turned recently to detection of the virus in wastewater.

The City of Fort Collins has also been giving the CSU system practice at handling very dirty samples. For the past two months, the city has been turning over samples of sewage to the lab so CSU could make sure its testing system was working well for this new type of testing.

Sewage testing has shown in other parts of the country and the world that it has value in spotlighting where virus levels are high and growing.

Where the samples are being taken
As of July 20, there are 11 utilities that have tentatively agreed to participate in the Front Range testing program, sampling from about 20 locations. They are:
• Aurora Water Sand Creek Reuse Facility
• Boulder
• Broomfield
• Colorado Springs
• Estes Park
• Fort Collins
• Longmont
• Louisville
• Metro Wastewater
• South Adams County Water and Sanitation District
• South Platte Water Renewal Partners

Sewage testing in Colorado actually began this spring with South Platte Water Renewal Partners, the Metro Wastewater Reclamation District and the Gunnison County wastewater treatment system pioneering poop testing in the state. That testing was done through a non-profit laboratory, Biobot Analytics, based in Somerville, Massachusetts.

Biobot Analytics had been doing this type of sewage testing to track other viruses like polio and hepatitis A and opioid use before it began testing for the novel coronavirus. Biobot is currently working with 400 wastewater treatment facilities in 42 states. But the delays for test results – as long as three weeks — and the increasing cost — $1,200 per sample — prompted Colorado to put together its own sewage-testing project.

The new state project got off the ground after it caught the attention of Gov. Jared Polis and his Innovation Response Team Task Force. Putnam said Polis had reached out to the tech community and the tech community found the idea intriguing.

“Polis embraced it. It was not a tough sell,” Putnam said. “He was excited about this.”  

Poop testing for COVID-19 has proved its usefulness in places like New Haven, Connecticut, which is working with the Yale School of Public Health; Tempe, Arizona; and Virginia Beach, Virginia.

The state of Utah has been testing for months and has set up a dashboard to show the levels of COVID-19 in the Cache Valley area around Logan. The testing there showed the virus had spiked in sewage a week before individual testing showed a big jump in the virus’ spread.

The Utah testing found the virus in all 10 sewage treatment plants tested and in 64% of the samples. The sewage test results showed the highest concentrations of the virus are in urban areas and that tourist communities have higher concentrations per capita than other areas of similar size and density.

MORE: Eagle County rolls out welcome mat, says “summer of the part-time resident” will aid coronavirus recovery

The Centers for Disease Control and Prevention is also looking at poop testing on a national level, but has not yet started any testing programs.

“There is a lot happening on this across the country,” said Nicole Rowan, the clean water program manager for the State of Colorado.

She said the facilities that have signed on for the Colorado testing will pull samples from influent at about 20 sampling sites plants for the next year. Those samples initially will go to CSU and eventually some are planned to also go to Metro State once a testing lab is ready to go there.

Rose Nash, the director of research and development at GT Molecular, said her company will also be a backup if demand for testing continues to grow. GT Molecular held a webinar last week for interested utilities and had more than 200 attendees. She said her company has been able to bring down the cost of testing to $295 per sample. Because the company developed the protocol for the testing with CSU, Nash said it will use the exact same process so the company can be used for overflow on the state project if need be.

Putnam said if the first year pans out, the plan is to continue and expand the testing and to pull even more specific data from sewage. He said it could potentially be used to pinpoint outbreaks at universities, schools, prisons and agricultural facilities – all places that have experienced outbreaks or have the potential for outbreaks. Putnam said he also hopes to expand the testing to the Western Slope.


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