Getting ‘tested before turkey’ this Thanksgiving? A guide to COVID-19 test options
Many South Carolina families are modifying their Thanksgiving plans this year due to the resurgent coronavirus pandemic, which has spiked nationwide in recent weeks as temperatures drop and people spend more time indoors.
More than 1 million COVID-19 cases have been reported in the United States in the past week, including 9,140 in the Palmetto State.
Public health officials say the safest way to spend Thanksgiving this year is at home with the people you live with, but if you are planning to travel or invite others over for the holiday there are ways to make the experience safer.
Gov. Henry McMaster on Thursday implored residents with Thanksgiving plans that include travel or gathering with extended family and friends to “get tested before turkey.”
Any South Carolinian could get tested at one of nearly 300 testing sites across the state and learn their COVID-19 status before the holiday, he said.
“Men and women and children of South Carolina, we have plenty of tests out there for you, plenty of locations,” McMaster said. “So don’t wait. Go ahead and get tested before turkey, and you’ll be glad that you did.”
Not all COVID-19 tests are equivalent, however, and some may not be appropriate in a given circumstance.
It’s important when seeking out a coronavirus test that you consider your options and choose the best fit because all tests have limitations and there’s not one right test for every scenario, DHEC physician and chief medical officer Michael Kacka said.
Types of COVID-19 tests
Broadly speaking, there are two types of COVID-19 tests: diagnostic tests and antibody tests.
Diagnostic tests are used to determine whether you have an active coronavirus infection, and can be broken down further into molecular tests and antigen tests.
Antibody tests, also known as serology tests, look for antibodies your immune system makes in response to the virus. These antibodies could take days or weeks to develop and may remain in your blood for several weeks or more after you recover from an infection. For that reason, antibody tests are used to determine whether you’ve previously been infected with COVID-19 — and may now have some immunity to the virus — but are not appropriate to diagnose an active infection.
To learn your current COVID-19 status in advance of Thanksgiving, you should get a diagnostic test. The diagnostic test you should select depends largely on whether or not you’re symptomatic.
Best bet: Molecular diagnostic tests
Molecular tests, many of which use a technique called polymerase chain reaction or PCR, detect the virus’ genetic material and are considered the most accurate way of identifying whether someone is infected with COVID-19.
Test samples are taken by swabbing the nose or mouth or collecting saliva. The deep nasal swabs that many people find uncomfortable were traditionally used to collect samples for PCR tests, but in recent months the Department of Health and Environmental Control has phased out the deep swabs in favor of shallow nasal testing, oral swabs or saliva tests, an agency spokeswoman said.
Research shows the accuracy of the less invasive molecular tests is “acceptable” when compared to the deep swabs, Kacka said.
Public health officials recommend the molecular test for anyone who is asymptomatic, but still wants to get tested — be it in advance of visiting with family over the holidays or just as a routine monthly precaution.
Keep in mind, however, that it will likely be at least two days before you get your results.
DHEC’s lab is generally able to turn around results in 48 to 72 hours, Kacka said, but at times backlogs may lead to delays. Private labs similarly can vary in how quickly they’re able to process results.
Saliva-based tests, like the one the University of South Carolina has offered students, faculty and staff since August, may return results within 24 hours, but are not as widely available.
USC recommends saliva testing only for people who are not experiencing COVID-19 symptoms.
The state has been slow to roll out its own saliva testing due to limited testing supplies and reagents, but three DHEC vendors recently began offering saliva tests at seven locations across the state, agency spokeswoman Laura Renwick said.
Because DHEC’s lab is still waiting for the supplies it needs to process saliva samples, its vendors currently send those samples to private labs for processing, she said.
Kacka, DHEC’s chief medical officer, said early data on saliva testing showed it to be “pretty reliable,” but not necessarily a better option than more traditional nasal swab testing.
“I would say it’s more of an alternative,” he said.
Not all people are able to provide the amount of saliva needed for proper testing, but those who prefer spitting into a tube over getting a swab stuck up their nose should feel free to get a saliva test.
“The only test that helps is the one you’re actually going to get,” Kacka said.
Antigen tests are fast, but are they accurate?
The other broad category of diagnostic tests are antigen tests, which detect specific coronavirus proteins.
Antigen tests, often available as “rapid” tests, are also done by swabbing the nose, but can produce results in as little as 15 to 30 minutes.
The quick turnaround is appealing for people who want to know their status immediately, but the speed may come at the expense of accuracy.
Rapid tests are good at identifying people who are at or near the peak of their infection, but are not considered as reliable for people who are asymptomatic.
If you test positive for COVID-19 using a rapid test, it’s highly likely to be accurate, but because the tests are not as sensitive as molecular tests, they’re prone to produce more “false negatives.”
That can create a dangerous problem when someone who is actually contagious with COVID-19 tests negative on a rapid test and believes they’re in the clear.
For that reason, the Centers for Disease Control and Prevention recommends that anyone experiencing COVID-19 symptoms who tests negative on a rapid test confirm their results using a more sensitive PCR test.
“It’s just not appropriate for that kind of surveillance-type testing for someone with no symptoms, for someone who just wants to know if they have (COVID-19),” Kacka said of rapid tests.
Rapid tests are, however, totally appropriate and highly beneficial if used in the right circumstances and within the manufacturer’s guidelines, he said.
Where to get tested
If you’re looking to find a testing location near you, DHEC maintains a list of COVID-19 testing sites on its website at scdhec.gov/covid19/covid-19-testing-locations.
As of this week, there were 293 testing locations statewide, including 53 DHEC and DHEC vendor locations and 240 non-DHEC sites, Renwick, the agency spokeswoman, said.
DHEC-sponsored testing is always free and open to anyone regardless of symptoms. Pre-registering is recommended.
A limited number of DHEC sites have testing on Saturdays, and many, but not all of the non-DHEC testing locations offer Saturday and Sunday testing. Some sites require appointments, so make sure to check in advance before showing up.
The DHEC website does not currently provide information about what types of diagnostic tests are available at each testing site, but is in the process of compiling that information and plans to make it available in the near future, Renwick said.
The agency urges testing for anyone who is symptomatic or has been exposed to someone who has tested positive for the novel coronavirus, and also recommends routine monthly testing for people who are regularly out in the community, even if they don’t have COVID-19 symptoms.
For general questions about COVID-19, call the DHEC Care Line at 1-855-472-3432, between 8 a.m. and 6 p.m. daily.
This story was originally published November 21, 2020 at 5:00 AM.