Coronavirus (COVID-19) and Medical Devices

The FDA has been working around the clock to increase the availability of critical medical products, including tests for the corona virus, to fight the COVID-19 pandemic. Learn more about the different types of tests and the steps involved.

Types of Tests:

There are two different types of tests –

• diagnostic tests and 
• antibody tests.

    A diagnostic test can show if you have an active corona virus infection and should take steps to quarantine or isolate yourself from others. Currently there are two types of diagnostic tests which detect the virus – molecular tests, such as RT-PCR tests, that detect the virus’s genetic material, and

 that detect specific proteins on the surface of the virus.

  

An antibody test looks for antibodies that are made by your immune system in response to a threat, such as a specific virus. Antibodies can help fight infections. Antibodies can take several days or weeks to develop after you have an infection and may stay in your blood for several weeks or more after recovery. Because of this, antibody tests should not be used to diagnose an active corona virus infection. At this time researchers do not know if the presence of antibodies means that you are immune to the corona virus in the future.

Different Types of Corona virus Tests:

1. Molecular test:

Molecular test is also known as Diagnostic test, viral test, molecular test, nucleic acid amplification test (NAAT), RT-PCR test, LAMP test.

Nasal or throat swab (most tests) and Saliva (a few tests) are collected as samples for testing. The reporting may take a day or a week depending on the location. This test is typically highly accurate and usually does not need to be repeated. Molecular test show if you ever had COVID-19 or were infected with the corona virus in the past.

2. Antigen test:

Antigen test is a rapid diagnostic test, however some molecular tests are also rapid. Nasal or throat swabs are collected as samples for testing. reporting needs less than an hour with this method. Positive results are usually highly accurate with this method but negative results may need to be reconfirmed with a molecular test method. Antigen testing gives definitive rule out of active corona virus infection. Antigen tests are more likely to miss an active corona virus infection compared to molecular tests. Your doctor may order a molecular test if your antigen test shows a negative result but you have symptoms of COVID-19.

3. Antibody test:

Antibody test is a serological blood test which detects antibody in serum. Blood serum sample is used for the processing. Reporting may need 1 to 2 days depending on the location. Sometimes a second antibody test is needed for accurate results. this test shows if you’ve been infected by corona virus in the past, whereas other two types shows active corona virus infection. Antibody testing diagnose active corona virus infection at the time of the test or show that you do not have COVID-19.

There are some new diagnostic tests available with alternative methods and benefits.

    Rapid, point-of-care diagnostic tests use a mucus sample from the nose or throat but can be analyzed at the doctor’s office or clinic where the sample is collected and results may be available in minutes. These may be molecular or antigen tests.

    At-home collection tests, available only by prescription from a doctor, allow the patient to collect the sample at home and send it directly to the lab for analysis.

    Saliva tests allow a patient to spit into a tube rather than get their nose or throat swabbed. Saliva tests may be more comfortable for some people and may be safer for health care workers who can be farther away during the sample collection.