COVID-19 testing has come a long way since March. In just a few months, experts have been able to understand this virus enough to know how to identify its presence with a simple test. With different types of testing options available, there are many questions that have come up about the accuracy of the testing and even when it is necessary to get a COVID test.
“There is little risk in getting tested for COVID,” says John McKinnon, M.D., an infectious disease specialist at Henry Ford Health. “But it is important to know that getting testing too early can lead to a negative test because there may not be enough of the COVID virus in your body to be detected.”
To help protect yourself and those closest to you from the coronavirus, make sure that you know when it is appropriate to get tested for COVID. Dr. McKinnon shares his expertise and answers some frequently asked questions related to COVID-19 testing:
What Types Of COVID Tests Are Available?
The types of COVID tests are split into two different categories – diagnostic tests and antibody tests.
There are two different diagnostic tests that are used to officially diagnose COVID-19 – molecular testing and antigen testing:
- Molecular testing (also called PCR or RNA tests). These tests involve swabbing mucus from deep in your nose or at the back of your throat. From there, the swab is sent off to a lab where it is examined for the virus’s unique genetic material. Molecular tests are the most accurate way to test for COVID-19. However, because the test needs to be evaluated by a lab, it can take longer to get your test results back.
- Antigen testing (also called rapid testing). Rapid testing involves a similar swabbing process as the molecular test, but it doesn’t need to be sent off to a lab or laboratory equipment. This means you can get your results back sooner. Rapid testing is the type of test you are more likely to get if you go to drive-thru testing sites. While these tests are very accurate at identifying COVID antigens, it may take a while for COVID antigens to appear in your system. This means it is possible to be infected with COVID but get a negative result from a rapid antigen test.
Knowing the limitations of rapid testing is important. For example, if you come in contact someone who tests positive for COVID and decide to get a rapid test a few days later, it may come back negative because the COVID antigens haven't shown up in your body yet. A few days later, you may develop symptoms of COVID and test positive. The risk comes with you potentially exposing others to the virus when you think you were in the clear following your initial negative result. .
The antibody test is a blood test that looks for COVID antibodies in your bloodstream.
“A positive antibody test means that you had COVID in the past at some point, whether you knew or not, and your immune system has developed antibodies to help fight off the virus,” says Dr. McKinnon. “However, an antibody test can’t tell you if you still have the coronavirus, so it is not recommended to make a diagnosis.”
When Should You Get Tested For COVID?
There has been a lot of discussion around when it is appropriate to get tested for COVID-19, and unfortunately, each situation is different.
“It depends on your specific scenario and symptoms,” says Dr. McKinnon. “And there is a difference between how you should approach testing if you’ve been exposed to someone with the virus versus if you are showing symptoms.”
If Exposed To Someone With COVID
If you find you were exposed to someone who tested positive, you should do the following:
- Quarantine. Treat the situation as if you have the virus as well. Don’t go out in public for 10-14 days. The duration of the quarantine will depend on when you get tested and local health guidelines. Separate yourself from others within your household.
- Monitor your symptoms. COVID symptoms won’t appear right after you come in contact with an infected individual. It may take a few days to develop symptoms. If you have symptoms of COVID, consider getting tested.
- Talk to your doctor. Your primary care doctor can help you determine if you should get tested based on your specific scenario.
If You Have Symptoms Of COVID
If you start developing symptoms of the coronavirus following exposure to someone who tested positive, get a COVID test. If you develop symptoms but aren’t aware that you’ve come in contact with anyone who has COVID, discuss your symptoms with your doctor to see if a test is necessary.
While COVID testing can offer peace of mind to individuals that were exposed to someone with COVID or are showing symptoms, it should not be misused. It is not appropriate to get a test in other scenarios such as:
- Every time you leave the house. There is very low risk is picking up the virus at the grocery store or while you are picking up food from a restaurant. Follow these best practices for handling food or deliveries that you bring into the house.
- Using a negative test result as an excuse. A negative test result is a snapshot in time and does not mean it is okay to gather in large groups, go to parties, travel, or forgo masks and social distancing. With the holiday season coming up, celebrations should look different this year and still follow COVID guidelines.
- You haven’t been exposed to someone with the virus. Don’t get a test just to get a test. With cases on the rise around the country, there is an increase need for testing of symptomatic patients and there are already a delays in getting testing results for patients in need. If there is little to no chance of you having come in contact with a person with the virus, save the testing for people that have been exposed or have symptoms.
“COVID testing is also required for hospital patients before in-patient operations,” says Dr. McKinnon. This is necessary to make sure hospital staff is taking appropriate precautions before, during and after the surgery to keep you and others safe.
What Do My COVID Test Results Mean?
As cases go up, testing sites are incredibly busy. This means that delays in test results are incredibly common. If you are waiting for test results, behave as if you are positive for COVID.
If you get a positive test result, meaning you have COVID-19, you do not need another test to confirm. All diagnostic tests are accurate at detecting the virus and you should proceed by isolating yourself from others until your doctor clears you.
If you have COVID symptoms and get a negative test result back from a rapid test, your doctor may ask that you get a molecular test to confirm the results and to continue isolation while testing determines if you have COVID-19.
This holiday season, it is more important now than ever to actively work to minimize the spread of the virus.We can do this by continuing to wear masks, wash hands, practice social distancing and avoid large social gatherings.
If you are experiencing symptoms of COVID-19, use our online screening tool to determine your next steps. For more information on ways to get care at Henry Ford and our response to COVID-19, visit henryford.com or call 1-800-436-7936.
Dr. John McKinnon is an infectious disease specialist who sees patients at Henry Ford Hospital in Detroit.