COVID-19 Testing

Last Updated September 2020 | This article was created by editorial staff and reviewed by Beth Oller, MD

Who should get tested for COVID-19?

If you think you have COVID-19, stay home and contact your family doctor to get advice on what you should do next. Information on COVID-19 testing options and availability is changing rapidly. Doctors are working with local and state public health offices to determine who needs to be tested and provide access to tests.

Because there is a shortage of COVID-19 tests in some areas, the Centers for Disease Control and Prevention (CDC) released guidance on who should be tested first. The CDC recommends that people with symptoms whose job or living situation increases their risk of COVID-19 should get top priority for testing. Some examples include health care facility workers and people who live or work in nursing homes.

The CDC’s next priority level for testing includes people who have symptoms of a possible COVID-19 infection. It also includes people without symptoms who are prioritized by doctors or health departments.

What tests are available for COVID-19?

Two types of tests for COVID-19 are currently available:

  • Diagnostic tests
  • Antibody tests

The U.S. Food and Drug Administration (FDA) made these tests available under an emergency use authorization. This means that they can be used during a public health emergency. They have not been fully reviewed and approved by the FDA.

At this time, we have limited information on how accurate COVID-19 tests are. It is possible for them to show positive results that are wrong (called a false positive). They can also show negative results that are wrong (called a false negative). Even if your test result is negative, it’s important to keep following your family doctor’s recommendations to prevent the spread of COVID-19.

What are the diagnostic tests for COVID-19?

Two kinds of tests are available to diagnose a current COVID-19 infection: a molecular test and an antigen test.

The molecular test is also called a polymerase chain reaction (PCR) test. It detects genetic material of the virus that causes COVID-19 (called SARS-CoV-2). This test requires a fluid sample collected by swabbing the inside of your nose or throat. It is the most accurate diagnostic test for COVID-19.

The antigen test requires a sample collected by swabbing the inside of your nose. This test works by detecting a unique protein on or around the virus that causes COVID-19. If enough of this protein is detected, the test is positive. This means that you have an active COVID-19 infection.

Antigen tests are faster than molecular tests, but they are not as accurate. If you have a negative antigen test, your doctor may recommend a molecular test to confirm it.

What is an antibody test?

The antibody test (also called a serology test) checks your blood for antibodies to the virus that causes COVID-19. Your immune system makes antibodies to help fight harmful viruses and bacteria. They are produced a few days or weeks after you are infected. Different antibodies are produced to fight different infections.

If antibodies are detected in your blood, it could mean that you currently have COVID-19 or that you have had COVID-19 recently. But a positive antibody test could mean that you were infected with a different coronavirus in the past. This is why antibody tests are not used to diagnose a current COVID-19 infection.

A negative antibody test means that it is likely you have not had COVID-19 in the past. It could also mean that you are currently infected with COVID-19 but haven’t started producing antibodies yet.

Researchers do not know yet whether people who have been infected with COVID-19 have any immunity to the virus. Regardless of your test results, you should continue to take steps to protect yourself and others from the coronavirus.

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