Record amounts of the RNA sequence of the virus that causes COVID-19 were found in samples at wastewater treatment facilities in Logan, Tremonton and Brigham City on Monday.
It’s too soon to see whether this is an indicator of a further increase in positive COVID-19 cases, according to Jeff Ostermiller. The Logan resident and senior scientist in the state Division of Water Quality said lab-confirmed positive cases tend to lag five to seven days behind wastewater results.
“It’s just like hospitalizations and deaths kind of lag behind identification of cases,” said Nathan LaCross, an epidemiologist at the Utah Department of Health. “It just takes time for that measure to actually catch up and for us to see that effect in the data.”
Nearly two months ago, Utah State University’s wastewater monitoring for SARS-CoV-2 in sewage resulted in isolating four cases in a residence hall of 287 students.
USU biological engineering professor Keith Roper, who’s collaborating with the Utah Department of Health and the Department of Environmental Quality for the testing, said the early detection program was crucial for finding a potential outbreak before it could occur.
“There were asymptomatic individuals identified,” he said, “and there were individuals identified who elected not to be tested but to quarantine off campus. As a result (of the monitoring), the individuals in those residence halls who might otherwise have had COVID-19 transmitted to them were protected.”
What started as a pilot program of 10 facilities throughout Utah has now expanded to 65 facilities and represents roughly 80% of the population.
Though USU has water-monitoring stations at each residence hall on campus, the rest of the valley is only being monitored at two locations: Logan and Hyrum.
Both of those sites are now showing an increasing amount of SARS-CoV-2 RNA in fecal matter, though Hyrum’s increase is not as exponential as Logan’s.
While the testing showed elevated traces of COVID-19 in wastewater in Hyrum before tests confirmed an outbreak at the JBS meatpacking facility there, when wastewater treatment facilities cover a large geographic area — such as in Logan — it can be hard to narrow down where the outbreak is occurring, according to LaCross.
“You can think of it like a lot of different rivers and creeks coming together,” he said. “You sampled downstream of that river. If you find something, whatever you have been looking for, you don’t know where upstream it came from. It’s something that could be everywhere.”
In order to specify neighborhoods, more “interceptor sites” need to be set up, which can be challenging because of the manpower needed, potential drilling, shutting down streets and refrigerating samples to prevent degradation.
Ostermiller said the department organized and determined where to test in different neighborhoods to narrow the search down, but with thousands of students coming to USU, off-campus student housing in Logan has been the focus of interceptor sites.
“With all of the students leaving for Thanksgiving, the university will stop sampling on-campus and the off-campus interceptor sites,” Ostermiller said, which may lead to other neighborhoods being sampled.
The current increase came less than one week after Gov. Gary Herbert transitioned the state of emergency to a public health emergency and mandated masks for most Utahns through Oct. 29.
Both Ostermiller and LaCross said preventative measures and virus mitigation methods like mask mandates have led to a decrease in COVID-19 traces in wastewater in places like Provo and Salt Lake in past months.
“It’ll take a good two or three weeks, at least, for things like mask mandates to really have an effect because the people who are getting sick now were exposed prior, right?” LaCross said. “They were exposed a week or two ago, something like that. The mask mandates will help people not get infected now who would have otherwise would have shown up in a week or two.”
The Bear River Health District, which covers Cache, Rich and Box Elder counties, reported an average of 71 new COVID-19 cases a day for the week ending Friday. There are an estimated 1,326 active cases in the district, meaning that many people have tested positive for COVID-19 within the last three weeks and have not died. Utah hit a new record of 1,960 newly confirmed COVID-19 cases on Friday, and BRHD reported 108, its highest single-day increase not tied to the testing clinic targeting JBS in early June.
“This is a record day for Utah — but not a good one,” Gov. Herbert said in a statement Friday. “Cases of COVID-19 are at an all-time high, and I am deeply concerned that COVID exhaustion is as well. Now is not the time to let down your guard. By public health order, masks are required in 21 counties. Wear one any time you are around someone outside your immediate household, even when around extended family or friends.”