Testing for COVID-19  (Source: CDC.gov)

There are two types of tests available for COVID-19 screening: antibody and diagnostic. Diagnostic tests check samples from your respiratory system (such as swabs of the inside of the nose) to tell you if you currently have an infection with SARS-CoV-2, the virus that causes COVID-19. Antibody blood tests, also called serologic tests, check your blood for antibodies that would show if you have had a previous infection. Antibodies are proteins that help fight off germs. A serologic test may not be able to show if you have a current infection, because it can take 1 to 3 weeks to make antibodies after symptoms occur.

We do not know if having antibodies to SARS-CoV-2 can protect someone from getting infected with that virus again, or how long protection might last. Scientists are doing studies to answer those questions. If you test positive or negative for COVID-19, no matter the type of test, you still need to take preventive measures to protect yourself and others.

Diagnostic Testing

Diagnostic tests can find the virus that causes COVID-19 in samples taken from your respiratory system, such as swabs of the inside of your nose. It is recommended that diagnostic tests be sent to a laboratory to analyze, a process that takes 1-2 days once received by the lab.
How to decide if you should get a diagnostic nasal swab test:
1. Not everyone needs to be tested for COVID-19. Here’s some information that might help you make a decision about getting a diagnostic test.
2. Most people have mild illness and can recover at home without medical care. They may not need to be tested.
3. At this time, there is no treatment specifically approved for people who have COVID-19.

In late April, the U.S. Food and Drug Administration (FDA) authorized a diagnostic test that lets you collect a respiratory sample at home. However, you still need to send your sample – a swab of the inside of your nose – to a laboratory for analysis. Home collection kits will be available through Marque in the coming weeks.

What to do after a diagnostic test

It takes around 1-3 days to get the test results from the lab. We will call you once they arrive based on the contact information you provided us.
  • While you are awaiting the results of your test, you must confine yourself to your home while our lab conducts the test. This is for the safety of our community and is the policy of the CDC. For the safety of all our patients, until test results are known, patients with suspected coronavirus may not receive clinic appointments or be able to spend time in the clinic. If you have a primary care provider, we will notify them of your testing and results with your permission.
  • If you test positive for COVID-19, our clinicians will go over your care plan so that you can recover from the virus safely and not be a risk to others.
  • You may be directed to one of our Marque COVID-19 positive treatment centers for a more thorough evaluation and treatment, so your condition does not worsen.
  • If you test negative for COVID-19, you probably were not infected at the time your sample was collected. However, that does not mean you will not get sick. It is possible that you were early in your infection when your sample was collected and that you could test positive later. Or you could be exposed later and then develop an illness. In other words, a negative test result does not mean you will not get sick later.

Serologic (Antibody) Testing

Antibody blood tests, also called serologic tests, check your blood by looking for antibodies, which show if you had a previous infection with the virus. Depending on when someone was infected and the timing of the test, the test may not find antibodies in someone with a current COVID-19 infection. Antibodies are proteins that help fight off germs. Serologic tests should not be used as the only way to diagnose someone as being currently sick with COVID-19.

If you test positive:

  • A positive test result shows you have antibodies that likely resulted from an infection with SARS-CoV-2, or possibly a related coronavirus.
  • It is unclear if those antibodies can provide protection (immunity) against getting infected again. This means that we do not know currently if antibodies make you immune to the virus.
  • If you have no symptoms, you likely do not have an active infection and no additional follow-up is needed.
  • If you have symptoms and meet other guidelines for testing, you will need a nasal diagnostic test. This test uses respiratory samples, such as a swab from inside your nose, to confirm COVID-19. A serologic test alone cannot tell if you have COVID-19.
  • It is possible you might test positive for antibodies and you might not have or have ever had symptoms of COVID-19. This is known as having an asymptomatic infection, or an infection without symptoms.
If you test negative:
  • If you test negative for COVID-19 antibodies, you probably did not have a previous infection that has gotten better. However, you could have a current infection. It is possible you could still get sick if you have been exposed to the virus recently, since antibodies don’t show up for 1 to 3 weeks after infection.
  • Some people may take even longer to develop antibodies, and some people may not develop antibodies.
  • If you have symptoms and meet other guidelines for testing, you will need a diagnostic nasal swab test. Remember, a serologic test alone cannot tell if you have COVID-19.