Spitting in a cup might be an easier, faster way to test for COVID-19, experts say
The typical coronavirus diagnostic test involves what many call an uncomfortable and sometimes painful experience as a healthcare worker sticks a 6-inch cotton swab deep in your nasal cavities.
Despite being unpleasant for many, the process requires medical supervision and uses up valuable personal protective equipment while shortages continue to plague some hospitals across the nation.
But there’s an alternative: saliva tests. Experts say they are easier to process in the lab, more comfortable for the patient and more affordable, especially for developing countries that may not have the resources to fund the expensive technology involved with swab tests.
Scientists hope saliva tests will eventually replace the traditional nasal swab method so testing can become faster and more widespread, informing policy makers on how best to reopen economies while preventing viral spread.
“The beauty of [a saliva-based test] is that it’s less invasive, and you could allow people to collect their own samples,” geneticist Dr. Evgeny Izumchenko, a University of Chicago assistant professor of medicine behind the development of a digital saliva-based test, said in a news release. “Everyone knows how to spit.”
The U.S. Food and Drug Administration authorized the first home-collected saliva-based coronavirus test in early May for a New Jersey laboratory.
Since then, a handful of other saliva tests — to be administered at-home only — have been granted emergency use authorizations, which is the approval of “unapproved medical products… to be used in an emergency to diagnose, treat, or prevent serious or life-threatening diseases or conditions,” the FDA says.
But long before the FDA’s decision to expand testing, universities started converting their labs into makeshift COVID-19 centers with the same goal in mind.
Saliva tests could prove more precise
The traditional COVID-19 diagnostic test uses a method called polymerase chain reaction (PCR) that can detect if the virus is present in a sample. The process is costly and complex, according to the researchers at UChicago.
But saliva tests can “measure how much of the virus is present, beyond a yes or no,” Dr. Nishant Agrawal, a UChicago surgeon-scientist and investigator on the study, said in the statement.
For their ongoing research, Agrawal and his team compared saliva samples with PCR samples and discovered the results matched up perfectly.
The researchers believe the saliva test could eliminate inconclusive results for patients who test negative for the virus, but still show symptoms, and for those who are asymptomatic.
“It’s possible that people who have the virus but don’t show symptoms have a smaller amount of virus that wouldn’t show up on (traditional) tests,” said Dr. Jeremy Segal, an associate professor and pathologist at UChicago, in the statement. “If they’re still able to spread the virus, being able to detect those people would be very important.”
The specificity of saliva tests could also be used to confirm COVID-19 patients don’t have tiny amounts of virus still hiding in their bodies before being discharged from the hospital, the researchers said.
Saliva tests could save time and maximize people tested
Another saliva-based test developed by researchers from Columbia University in New York can provide “reliable results in about 30 minutes,” according to a university news release.
Current diagnostic test results can take several days, depending on who collected the sample, which has to be shipped to a lab before being analyzed.
Columbia’s test, however, skips that step. Saliva is collected in a cup then placed in a warm tube filled with “enzymes and reagents” that detect if coronavirus is present, the researchers said.
If the patient is infected, the fluid inside the tube will turn yellow. If not, the fluid will turn red — all under an hour.
The test was developed from technology used to look for “genetic abnormalities” in embryos for women undergoing fertility treatment, according to the researchers.
“We realized that the same technology that we use to help create lives could be repurposed to help save lives during the COVID-19 pandemic,” Dr. Zev Williams, the chief of the division of reproductive endocrinology at Columbia University Irving Medical Center,” said in the release. “The test serves a critical need for more widespread testing to help us safely reopen economies closed by the pandemic and prevent future outbreaks.”
This is why university researchers behind different saliva-based COVID-19 tests are seeking emergency use authorizations from the FDA.
Because saliva tests are easier to collect, cheaper and provide quicker results in some cases, experts say they can be used to screen people before entering public spaces such as summer camps, airplanes and nursing homes to help curb spread of the disease.
Researchers at the University of California, Berkeley are testing their own saliva test to hopefully “ramp up the monitoring of students, faculty and staff as the campus gradually opens in preparation for the start of classes in late August,” according to a new release published Tuesday.
Regular testing would allow university officials to catch and isolate infected, asymptomatic people early on to prevent viral spread.
This story was originally published July 1, 2020 at 10:24 AM with the headline "Spitting in a cup might be an easier, faster way to test for COVID-19, experts say."
