COVID-19 testing basics
Here is some information on how the different types of COVID-19 tests work and who should be tested.
If you’re struggling to parse through all of the information about the different COVID-19 tests, you’re not alone. Finding a credible, centralized source of information has been difficult for many, and this virus is still so new that what you thought was the most up-to-date information can change from one day to the next.
There are, however, plenty of facts we do know about testing for COVID-19. To start, tests are crucial to helping everyone better understand the virus, contain its spread, and make more informed personal choices day-to-day.
But should you get tested? If so, which test is right for you? Here is some information to keep in mind as you navigate the uncertainties of living in a pandemic.
What are the different types of COVID-19 tests?
In general, testing for COVID-19 falls into two categories — viral testing and antibody testing. Which test you get generally depends on your answer to one key question: Do you think you may be infected now, or do you suspect you might have been in the past?
If the first question describes you, your provider may suggest a viral COVID-19 test.
Viral testing determines whether a person has an active infection. This means that their immune system is currently working to fight off the virus that causes COVID-19. Most tests require a deep swab into your nose (although some labs have started offering less sensitive saliva tests).
Now, more than ever, these viral tests play a critical role in public health, explained Heather Signorelli, D.O., chief laboratory officer at HCA Healthcare. “It’s really important to have as much testing for active infection as we can, so that we’re identifying individuals who are infected,” she explained.
Fortunately, testing has come quite a way since the virus first emerged in late 2019. That progress has helped scientists create a wider range of viral testing options, including polymerase chain reaction (PCR) tests, which detect the molecular presence of the virus, and antigen tests, which identify viral proteins.
Each kind of viral test comes with caveats: PCR test results are generally more accurate, but they also take more time, since they require lab processing. Antigen tests are fast, but they may not be as accurate in ruling out a possible infection.
“The PCR test is a gold standard because it’s the most sensitive test, but antigen testing is still a really good test,” Dr. Signorelli said. “We’re going to need to have a mix of those two in order to combat this pandemic.”
Antibody testing requires heading to a clinic or a lab for a blood test. When the immune system beats an illness, it creates antibodies. Because the test is able to detect the presence of antibodies in the body, it can indicate whether someone has already had (and overcome) an infection — even if it was weeks ago.
While the results of antibody testing can help researchers see who may have already had or been exposed to the virus, it has some downsides — especially if people change their behaviors, like going back to work or school, based on the results. For one thing, a positive antibody test may not mean you’re safe from getting sick again.
“We’re seeing employers or individuals trying to test a whole bunch of people with antibody testing, but that’s not reliable,” Dr. Signorelli said. “If you have a positive antibody test, we don’t know how long those antibodies stick around for — or how protective they are. It doesn’t mean you don’t have to wear a mask or worry about getting reinfected.”
Still, don’t let that discourage you from getting an antibody test if you’d like to know whether you’ve already had COVID-19. Just be careful not to mistake those results for immunity to a future infection.
How to get tested for COVID-19
If you have symptoms of COVID-19 or have been exposed to someone with a confirmed case, the first step is to stay home and call your provider. They will help you decide whether you should get tested and which test best fits your needs. They can lay out options for viral testing in your area, such as drive-up testing sites and urgent care centers. You can also reach out to your local health department using this health department directory from the National Association of County and City Health Officials.
It may even be possible to get tested at home using nasal swabs for the PCR test. Similar to DNA testing, at-home services ship you a collection kit that you can mail back for processing. However, be careful to use the swab in the right way for accurate results. The prospect of an instant at-home antigen test is exciting, but is still a ways off, according to Dr. Signorelli.
While you wait for your results, act as if you have COVID-19 and self-isolate until you get a negative result. Even then, you may need to quarantine for an additional 10 to 14 days if you’ve been exposed to someone with COVID-19. The rules of quarantine apply: Stay home, avoid physical contact with others, and wash your hands regularly.
What to do after you get your results
When you get your results, discuss the precautions you should take with your provider. If you test positive, for example, you’ll need to focus on your recovery and on not spreading the virus to others. The Centers for Disease Control and Prevention recommends avoiding contact with others until:
- It’s been at least 10 days since your symptoms started.
- You’ve gone at least 24 hours without a fever (without using fever medicine).
- You feel better.
It’s important to isolate until you meet all three criteria. You may also get a phone call from a contact tracer, who will ask questions related to your recent history and contact with others. Cooperate as best you can with their questions — your answers can help public health leaders track, and ultimately slow, the spread of the disease.
Most importantly, work with your provider and follow their advice around COVID-19 testing. By staying informed and cautious, you can do your part to help keep yourself and others safe.
If you still have questions about whether to get tested or which test to get, contact us for more information.