Site Menu

Types of COVID-19 Tests

11/6/2020
As we resume working and attending school, we need to be cautious about how we deal with the onset of symptoms and what measures to take for prevention and treatment. The first step to taking proper precautionary measures if you suspect infection or had an infection in the past is to get tested for COVID-19 and there are currently a few options available.
 

There are two categories of lab tests that test for COVID-19: Molecular tests, which look for evidence of active infection; and Serology tests, which look for previous infection by detecting antibodies and are mainly used for investigational purposes and not for diagnostic purposes. The three main types of tests within these categories include the molecular, antigen, and the antibody tests. 

4.png
 

ACTIVE INFECTIONS

Molecular tests are looking for the core of the virus, the DNA, that is by far the most accurate to detect an active virus as you are looking for the virus particle. This type of test is generally conducted by collecting saliva or mucus from the back of the throat and usually takes a couple days to get a result. It is the most accurate form of testing. If it comes back positive, you have COVID-19 and if it comes back negative, you very likely do not. 
 
Rapid tests are frequently used in the emergency department and are one of the initial tests conducted when diagnosing patients, as results can be determined within an hour of conducting the test. Instead of checking for the core of the virus, these tests are checking for the parts of the outer shell of the virus to see if antigens exist. This form of testing is not as accurate, as tests may come back negative and there may still be a strong suspicion for COVID-19 infection, which should then be followed by a molecular test for more accurate results. This test is conducted by taking a swab from the throat or the back of the nose, much like the PCR test, but quicker and easier to do.

If you test positive for COVID-19, know what protective steps to take if you are sick and contact your healthcare provider if your symptoms worsen or if you have health-related questions. Most people have a mild illness after getting infected with COVID-19 and can recover at home without medical attention.

A negative test result indicates that you did not have COVID-19 at the time of testing or that your sample was collected too early in your infection. If you are tested in the days immediately after exposure, the false negative rate can be anywhere from 50% to 100%. You can still be exposed to COVID-19 after getting tested and may need another test for more accuracte results. If you feel sick after a few days, contact your healthcare provider to discuss taking another COVID-19 test.

3-(2).png
 

PASSIVE IMMUNITY

As far as testing for the body’s response to COVID-19, the antibodies test is far more effective for seeing if immunity for the virus exists. This type of test is not testing for the active infection; it is testing for your body’s response. Therefore, if this person has had COVID-19 at some point, this testing can be used, but it takes days, weeks, and even months for the body to develop antibodies. This test is worthless to check for an active infection, but if it comes back positive, it implies that your body has been exposed to the virus.

A positive test result indicates that you may have antibodies from an infection with the virus that causes COVID-19. You may test positive for antibodies even if you have never had symptoms of COVID-19. This can happen if you had an infection without symptoms, which is called an asymptomatic infection. Having antibodies to the virus may provide protection from getting infected with the virus again, but it is still unclear how much protection the antibodies may provide or how long this protection may last. You should talk with your healthcare provider about your test result and the type of test you took to understand what your result means. Your provider may suggest you take a second type of antibody test to determine the accuracy of the first test.

A negative test result indicates that you may not have an active infection of COVID-19 and should still confirm the test results with your healthcare provider to better understand your results and the effectiveness of the type of test taken. The test may be negative if you have a current infection or if you’ve been recently infected because it typically takes 1–3 weeks after infection for your body to create antibodies, which means that it is possible you could still get sick if you have been exposed to the virus recently. Additionally, the time it takes to develop antibodies varies from one person to the next which means you can still spread the infection.

5-(2).png
 

Different Types of Coronavirus Tests

   Molecular Test Antigen Test Antibody Test
Also known as... Diagnostic test, viral test, molecular test, nucleic acid amplification test (NAAT), RT-PCR test, LAMP test  Rapid diagnostic test 
(Some molecular tests are also rapid tests.) 
Serological test, serology, blood test, serology test 
How the sample is taken... Nasal or throat swab (most tests) 
Saliva (a few tests) 
Nasal or throat swab  Finger stick or blood draw 
How long it takes to get results... Same day (some locations) or up to a week  One hour or less  Same day (many locations) or 1-3 days 
Is another test needed... This test is typically highly accurate and usually does not need to be repeated.  Positive results are usually highly accurate but negative results may need to be confirmed with a molecular test.  Sometimes a second antibody test is needed for accurate results. 
What it shows... Diagnoses active coronavirus infection  Diagnoses active coronavirus infection  Shows if you have been infected by coronavirus in the past 


According to the Association of American Medical Colleges, in the early days of the pandemic, scientists were uncertain if those who showed no signs of illness were infectious. They have since discovered that 40% to 45% of COVID-19-positive individuals are asymptomatic. However, asymptomatic individuals carry just as much virus in their throats, lungs, and nasal passages as those showing symptoms. Therefore, you want to get tested to make sure you are not an asymptomatic carrier and to determine whether you are in the pre-symptomatic phase.

Even if you have tested negative for the virus, it does not mean you are not harboring the virus. The average onset of symptoms is five days after exposure and the peak infectiousness of the illness is two days before and one day after the onset of symptoms. To avoid a false negative test, you should get tested five days after possible exposure and be extra cautious about social distancing and self isolation in the days leading up to your visit.

1.png

During this pandemic, Assist America’s global team is engaged to continually assess and monitor the impact of the pandemic and be available as a trusted resource for our Members. Assist America has adapted its global emergency assistance offering and provides many COVID-19 services and resources, such as testing site referrals, medical referrals, medical monitoring, prescription assistance, and stranded traveler assistance. For more COVID-19 documents and resources, download the Assist America Mobile App or visit our online webpage.