Wastewater COVID testing

Lead operator Jason Chou collects a water sample at the West Boise Water Renewal Facility, Thursday, Aug. 13, 2020. Samples are taken at various stages in the wastewater renewal process and tested for COVID-19.

BOISE — Two new variants of the novel coronavirus (SARS-CoV-2), including one that may be more infectious than current variants in Idaho, have been discovered in wastewater samples from three Ada County cities, Central District Health announced Wednesday.

The results are from ongoing wastewater sampling and testing, done in collaboration between the city of Boise a University of Missouri laboratory.

The so-called U.K. (B.1.1.7) and California (CAL.20C) variants were discovered in wastewater samples from the cities of Boise, Garden City and Eagle. The new variants, which have yet to be confirmed in Idaho through COVID-19 testing on individuals, each represented 2% of the virus that was sequenced during a six-day period last month.

Sequencing is the process used by scientists to decode the genes of a virus to learn more about the virus and how it is changing.

“While we haven’t detected the B.1.1.7 (U.K.) or the CAL.20C variants in clinical samples yet, we have presumed the variants were circulating in Idaho,” said Dr. Christopher Ball, bureau chief for the Idaho Bureau of Laboratories, in a news release. “We are grateful to the City of Boise for doing this important work. The Idaho Bureau of Laboratories is on track to sequence SARS-CoV-2 samples in-house by the end of the month, which will both speed up the time to results and expand the number of samples in our strain sequencing program.”

Ball continued, “In the interim, we continue to work with clinical labs around the state to receive samples for sequencing. Several partners including the Centers for Disease Control and Prevention, regional universities, and commercial reference labs are sequencing Idaho samples. To date, 239 Idaho SARS-CoV-2 sequencing samples have been characterized in public databases. We look forward to having more robust and local sequencing capabilities in the coming weeks.”

Kimberly Link, Central District Health’s communicable disease control manager, told the Idaho Press in an email that RNA viruses, such as the novel coronavirus, tend to mutate or change more rapidly than those made up of DNA. Link said, “it’s not surprising that many different variant types may be circulating at the same time.”

“Most of the time, these changes are minor and don’t affect how well a virus can infect a person or the severity of illness that it causes,” she said. “But sometimes there are changes in its makeup that give it an advantage over other variants. That’s what happened with the B.1.1.7 British variant. It has a change in an area of the virus called the spike protein. This is the place where the virus attaches to a cell during infection. This change has made it easier for the virus to attach and means that exposure to fewer virus particles can lead to infection.”

As for the California variant, Link said, “It has mutations that affect its spike protein, but scientists aren’t sure at this point if those changes make it more infectious, like we’ve seen with the British variant.”

Evidence of the two variants was detected in wastewater samples submitted on Jan. 25 and Jan. 30 — dates when Ada County COVID-19 case counts were higher than they have been in more recent weeks, making the samples much easier for the lab to sequence, the news release said. According to the city of Boise, as cases continue to drop, it will become more difficult to sequence wastewater samples, the release said.

“I’m grateful we have a wastewater testing program, and that it could tell us that these variants are indeed in Boise so that we are reminded, again, that we aren’t out of the woods yet,” said Boise Mayor Lauren McLean in the release. “We’ll get through this, and our community will recover, if we remain vigilant in maintaining our distance, wearing masks, and following other health protocols.”

The city of Boise has been sampling wastewater to test for the coronavirus since May. Wastewater testing measures the quantity of coronavirus in used water; it does not reveal the number of individuals currently infected with COVID-19. Samples submitted by the city include wastewater from the sewershed that includes the cities of Boise, Eagle and Garden City, representing about 290,000 people. No personal information can be collected through the testing process.


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