Georgia researchers develop coronavirus saliva test

For millions of Americans, getting tested for the novel coronavirus involves a quick nasal swab a long wait for answers.

Dr. Jose Vazquez, Chief of Infectious Diseases at Medical College of Georgia at Augusta University, says diagnostic testing is critical because it reveals who needs to quarantine and who is safe to go back out into the community.

Yet, with a surge in the demand for coronavirus testing, bottlenecks at labs, and shortages of testing kit supplies,

Dr. Vazquez says it is difficult to do enough testing to get out ahead of the virus. 

"We can do 1,000 tests a day,"  Vazquez says. "But, if we don't have the chemicals, the reagents, to do the studies, we can't run them.  That is something everyone is talking about."

So, is there a better way to test for COVID-19?

The FDA has granted emergency use authorization for "pool testing," or screening up to 8 people at the same time.

Pool testing is already commonly used to screen donated blood for diseases like HIV and hepatitis.

In this case, it could be helpful in screening a larger sample of people in low-risk groups, who are asymptomatic, and likely to test negative, like college students or residents in a retirement community.

A sample is included for each person in the pool.

If the pool of tests is negative, everyone is considered negative for the virus.

If the pool result is positive, each person would be retested separately.

The Medical College of Georgia is working on another approach to diagnosing COVID-19: a saliva test.

Dr. Vazquez says having a test that involves spitting into a tube would require less close contact and risk for the health care workers doing the testing.

"It would be so much better, so much easier to reduce the exposure, if we just gave a tube, and be able to have the same sensitivity, and the same specificity, that we do with the nasal pharyngeal (test)," Vazquez says.

Researchers at Rutgers University were among the first to develop a saliva-based test to diagnose the virus.

The University of Illinois Urbana-Champaign is using a saliva-based test to screen returning students and faculty.

In New York, Syracuse University plans to pool its saliva tests, screening as many as 25 students at a time for the virus.

The saliva test, Dr. Vazquez says, is much like a DNA test you might take to learn more about your ancestors.

"So, theoretically, we could give it to the individuals, and they could go out to the car, or they could do it at home," he says.

Right now, Dr. Vazquez says, the nasopharyngeal or nasal swab is the testing "gold standard.”

In their tests, he says, the nasal swab has proven to be accurate than the saliva test

He says they are tweaking their test to try to improve both its sensitivity and specificity.

Yet, Dr. Vazquez believes, the saliva test will be ready for wider use down the road, giving Americans another option for diagnostic testing.

"I mean we've only been working with the virus for six months, not a long time," he says. "So, yes, I definitely think so."