By QUINTON SMITH/YachatsNews.com
During four days in mid-July someone – maybe just one visitor or two – used the toilet in their vacation rental or motel room in Yachats.
They carried the coronavirus.
But then they left town — and took the virus with them.
Public health officials know that because since June a research team from Oregon State University were testing the city’s wastewater for the virus that causes COVID-19.
The first weeks of sampling of Yachats’ wastewater in late June and early July showed nothing. Then the scientists detected a “moderate” level of the virus in samples taken July 15 and July 18. Genetic testing of six samples over the next three weeks found no detectable trace of it.
“If it stays that means you have community spread and it didn’t go away with the tourist,” said Ken Williamson, the head of research for Washington County’s Clean Water Services. “The important thing is that it went away and didn’t spread into the community.”
“To me that suggests that controls people have in place are protective,” said Williamson, who has a second home in Yachats, and who wanted to test the impact of tourists on small communities.
What Williamson and a team of OSU researchers found – and didn’t find – in Yachats was replicated in June and July for the cities of Newport, Lincoln City, Depoe Bay, Siletz and Toledo. Waldport didn’t participate.
Testing in Newport, Yachats and Depoe Bay will continue through Labor Day. In Depoe Bay, testing has shown moderate and then no levels of the virus. The latest results in Newport showed a strong presence in late July and then a downward trend in through early August.
The Lincoln County testing is part of a special $100,000 National Science Foundation effort to urgently seek reliable ways to detect SARS-CoV-2 – the virus that causes COVID-19 – in municipal wastewater.
Why?
Because genome laboratories – there’s one at OSU – are so good and precise that samples taken from sewer plants or neighborhood pump stations can detect its presence in a community when people carrying the coronavirus flush their toilets.
And, just as importantly, they detect the virus from everyone — people who don’t show symptoms of COVID-19, estimated to be 40 to 80 percent, as well as those who are sick and get a test.
This summer in Newport, the epicenter of Lincoln County’s 457 cases and 13 deaths, researchers sampled more frequently and widely. Their sewer surveillance added another layer of scientific evidence to two rounds of person-to-person COVID-19 tests in randomly selected neighborhoods by a special OSU team to determine the prevalence of coronavirus.
Scientists hope that by detecting the virus in wastewater it can serve as an early alert for local or state health authorities to consider issuing warnings, increasing precautions or instituting restrictions.
This week, University of Arizona officials said wastewater surveillance at a dorm filled with students was able to detect the virus, follow up COVID-19 tests found two asymptomatic cases, and the school isolated them before the illness spread to 311 others.
“As long as you are flushing the toilet you are participating,” said Tyler Radniecki, an associate professor of environmental engineering at OSU and one of the project’s leaders. “It gives you a pretty inexpensive check on your community’s health based on what you are doing – or not doing.”
And now the coronavirus chasers have just landed a $1.2 million grant from the Oregon Health Authority to do the same work in 43 cities across Oregon for the next 30 months.
Sewer testing not new
For decades scientists have been testing wastewater for everything from pharmaceuticals to plastics. The last time genetic labs chased a virus, however, was to detect polio in Israel in the 1990s, said Radniecki.
When the coronavirus struck early this year, scientists in the Netherlands, France and Australia quickly started testing sewers.
The big breakthrough came when researchers in China made public the RNA sequence of the coronavirus, said Williamson, who spent 40 years as a professor at OSU. Knowing that the university had a gene lab, he called Radniecki and suggested they now had the tool to trace the coronavirus.
Along with colleague Christine Kelly, they applied to the National Science Foundation and were one of six projects selected.
“That got us going,” said Radiecki.
Newport is biggest test case
A month or so before that, professors in OSU’s Colleges of Public Health and Human Services, Veterinary Medicine and Science started a unique project called TRACE to sample volunteers in Corvallis neighborhoods for COVID-19. By randomly testing hundreds of people they hoped to determine the virus’ prevalence in the community – not just the number of positive results from people who felt ill and got a test.
That project moved to Bend, where OSU has a campus and where officials were worried about the influx of summer tourists. Results in both cities showed that only 0.1 percent to 0.2 percent of residents had COVID-19.
“And then Newport happened,” said Radniecki.
On June 6, Pacific Seafood announced a COVID-19 outbreak among 124 workers there. Until then, the county had just 16 cases. But the virus from seafood workers spread into the Newport community, infecting family members and friends and shutting down numerous other businesses. Now, with a total case number of 187, the Pacific Seafood outbreak remains the largest among private businesses in Oregon.
The outbreak quickly overwhelmed the county’s small health department. The state and neighboring counties rushed in help. And in June and July, OSU brought its TRACE COVID-19 team to Newport to knock on doors in randomly-selected neighborhoods and ask people to take a COVID-19 test.
With them came Radniecki and his sewer samplers.
Sewer samplers join Newport effort
The door-to-door sampling in Newport by OSU’s virus tracers workers took place over two weekends in June and July and collected 1,120 nasal samples. The June tests showed 3.4 percent of Newport residents had the coronavirus – 17 to 34 times higher than the rate found in Corvallis. The July samples indicated the prevalence had dropped to 0.6 percent.
In an effort to provide another layer of evidence, the city of Newport and Radniecki’s staff took sewer samples from 26 locations around the city during the same time. Their testing showed a steady increase in the virus from in mid-June and then a steady decrease after that.
But the big goal in Newport was to see if there was a correlation between what Radniecki found in the sewer system with the sampling of the 1,120 individuals.
Radniecki is cautious about detailing the bigger picture results.
His team is working on a scientific paper expected to be released soon detailing their findings. On Tuesday, they are scheduled to present their findings to a conference of water experts.
But Williamson is less cautious.
“The results we got in Newport are as good as what is in the scientific literature,” Williamson told YachatsNews, because of the correlation of sewer testing and OSU’s neighborhood COVID-19 testing.
OSU researchers started taking samples at the Yachats wastewater treatment plant in June and will continue through Labor Day.
Sewer testing expands statewide
The correlation is important because sewer testing costs a fraction of COVID-19 tests and because it picks up all carriers – those with symptoms and those without. Tests can also be turned around in four days, and could get faster.
After showing that sewer sampling can correlate with actual test results, the key will be moving into areas or neighborhoods of larger cities or testing wastewater plants in smaller communities.
That’s the purpose of the Oregon Health Authority grant – to provide an early-warning system for smaller cities across the state and build on surveillance work already conducted in Lincoln County, Corvallis, Bend, Hermiston and Boardman.
“We can monitor its rise and fall, detect priority hotspots and then alert the appropriate health authorities, medical researchers and other decision-makers who can go in and take it from there with their knowledge, skills and technologies,” Radniecki said.
Katie Corliss, an intern at Clean Water Services in Washington County, processes samples for coronavirus testing taken from sewer systems there.
Williamson’s organization, Clean Water Services, is already testing 20 sites around Washington County, where there have been 3,610 positive cases and 35 deaths.
This fall, OSU will also conduct its COVID-19 sampling of students and staff on its three campuses, including the Hatfield Marine Science Center in Newport. Radniecki and Kelly will also be testing wastewater.
“The goal there is to identify hotspots within the university community for follow-up testing and to provide a general sense of the trends of the virus at the university locations,” Radniecki said.
Lewis & Clark College in Portland is also contracting for wastewater tests.
“There’s more and more people who are interested,” said Williamson.
And that’s what gives the researchers hope.
“I’m pretty sure we can make positive change,” said Radniecki. “It’s exciting and stressful. But it feels good to be doing a part.”