Swish, Gargle, Repeat.A researcher from the University of Arizona tried to create a new way of testing the presence of COVID-19, relying only on a simple saltwater rinse and gargle for students and employees of the university who are dreading the swab up the nose.
On the campus, two types of tests have usually been offered to students and employees so far to detect the presence of COVID-19: the quick-turnaround antigen tests and the polymerase chain reaction test – but both require the nasal swab.
Michael Worobey, head of the Department of Ecology and Evolutionary Biology who specializes in the evolution of viruses, began using the mouth rinse test in limited campus populations after reading a paper on the test published by researchers in British Columbia on medRxiv, a preprint server for health sciences research.
"It's vastly more tolerable than the nasopharyngeal swab – and people can do it all by themselves and even keep their mask on almost the whole time," said Worobey.
He even demonstrated the procedure himself. After opening a crayon-sized, pink plastic vial containing a liquid, "you pull your mask down, and you just squirt a bit of sterile saltwater into your mouth," he explained.
The liquid needs to be swished around in the mouth for five seconds, then the head needs to be tilted back for the 10 seconds of gargling. After a total of three cycles of swishing and gargling, the liquid should be spit into the sample cup and finally the lid must be screwed back.
"And that's it," he says. "You're done."
"Our system allows the participants to painlessly collect [the] virus from the back of their throat in a way that, so far, seems superior in terms of its ability to detect the virus," Worobey said.
When Worobey tested the very first person on the University campus, using both the nasal swab and the saline gargle samples, the virus was detectable only in the gargle sample.
According to the study, out of more than 100 people screened, he now has paired nasopharyngeal and saline gargle samples from 30 coronavirus-positive patients and discovered that, by comparison, the oral rinse samples detected the virus in about 20% more patients than the nasopharyngeal ones.
"This shows that the salt rinse and gargle test can be more sensitive and catch an infection you'd miss with the nasopharyngeal test," he said. "It also suggests that it's doing a good job of detecting [the] virus in people who have or recently had the virus."
If success with the test continues, it could have the potential to transform how testing is done.
"COVID-19 remains a significant public health threat, and testing has been a critical part of the University of Arizona's test, trace and treat strategy to keep our students and employees as safe as possible," said UArizona President Robert C. Robbins. "If this test proves to be as promising as early results indicate, it could eventually allow us to ramp up our already robust testing efforts in a really innovative way that allows us to administer high-quality and highly tolerable tests to large numbers of people."
"That is an application where I could really see huge benefit to a safe, inexpensive – but most importantly less invasive – sampling modality like this," Worobey concluded.