science environment

Experimental COVID-19 test at UO replaces nasal swab with saliva sample

By Erin Ross (OPB)
Portland, Ore. July 27, 2020 1 p.m.

Oregon is once again facing a COVID-19 test shortage. With commercial labs swamped, Oregon is one of several states turning to universities to develop new tests.

On Thursday, the University of Oregon began trials on a new COVID-19 test that uses saliva spit into a tube. If it works and gets approved, the university hopes it can raise the testing capacity in Lane County and neighboring communities.


“From the very beginning, back in March or April, we realized that testing was going to be a critical piece of the state of Oregon being able to reopen and stay open,” said Cassandra Moseley, the interim vice president for research and innovation at the University of Oregon.

Moseley is taking an executive leadership role on the project, called COVID-MAP. As a research university, the U of O has experience doing different types of public health surveys and working with the equipment necessary to test for COVID-19. The university set aside a lab for COVID-19 testing, raised funds for equipment, and worked to get the lab certified for medical research.

Related: Delayed test results make efforts to contain COVID 'unworkable' in Oregon

Most COVID-19 tests currently rely on a certain type of swab, called a nasopharyngeal swab. It's long enough to be stuck far up a patient's nose. But these swabs have been in short supply and have proven difficult for hospitals to get. The U of O and other organizations are looking instead at saliva. Participants will spit into a tube and then hand the tube over.

There are a lot of benefits to this method, if it works.

“The standard method is a nasopharyngeal swab,” said Leslie Leve, a human subjects researcher at the U of O and one of the lead scientists on the study, “but that requires a medical provider, and it’s not particularly comfortable.”

But with a saliva test, participants can collect the sample on their own. That means less medical staff are required and helps preserve the protective equipment they need to wear, like face masks and shields, while collecting nasal samples.

Bill Cresko, a biologist who co-leads the study with Leve, said the method means tests can be processed faster, too. Labs need humans to extract viral RNA from nasal swabs. But a tube full of saliva can be processed by a robot.


“We did an analysis, and to take swabs out of tubes meant about two hours of man time versus about two minutes of the robot’s time,” Cresko said.

The U of O will use a different method to test their samples. The standard approach, which the state lab and commercial labs are using, involves something called a qPCR or rtPCR test. The U of O team plans to use "next-generation sequencing." Cresko said there are two major benefits to this type of test: It can process a lot of samples very fast and, because it's done by robots, it uses smaller amounts of chemicals. Cresko hopes that will help the lab avoid chemical shortages.

But before they can roll the test out, they need to make sure that it actually works and get FDA approval. For that, they need to confirm 30 out of 30 true positives, and 30 out of 30 true negatives — and that means testing a lot of people, since it can be hard to tell who is sick.

“All the tests need to be done at the same time,” Leve said, “so we can’t just look for confirmed cases and test them.”

Volunteers were tested for COVID-19 in three different ways: with a spit test, with a self-administered nasal swab and with qPCR, collected using the standard methods of nose or throat swabs taken by a health care professional.

“We wanted to have more than one method for testing, since we know some ages and demographics have trouble with saliva samples,” Leve said, which is why they’re also testing a self-administered nasal swab. The qPCR will be used to confirm that the tests work.

Related: Pandemic Reveals Itself As A Threat To Rural And Urban Oregonians, Alike

After doing several trials in Lane County, which has a relatively small number of Oregon’s COVID-19 cases, researchers didn’t have enough positive samples to meet Food and Drug Administration requirements. So they turned to Marion County, which has been a hotspot for the last several months.

To try to find positive cases, Marion County helped pinpoint three zip codes with high rates of COVID-19, and recruited volunteers from those neighborhoods.The trial went well, and the results are still pending, Cresko said. But with only 150 tests done so far, researchers think they’ll need to do several more tests before they have enough positive results to get approved.

“We want to get this done yesterday,” Cresko said. “Well, as soon as possible.”

Once the university has met the criteria, it will submit the test to the FDA for emergency authorization. That process usually takes about a month.

If approved, the test will help the U of O screen students for the coronavirus when campuses reopen. The university also plans to collaborate with Lane County to use the tests for disease surveillance. It’s unclear how much the test will cost, but the U of O will make it available to other nearby communities if it’s not too expensive.