COVID-19 Tests: What’s Available & What are the differences?

There are a few types of COVID-19 tests currently available in Singapore. Find out what are they and which one is more suitable.

At the moment, there are two main types of COVID-19 tests commonly used to detect infections. Diagnostic tests are done to confirm if you currently have the virus and antibody (serology) tests help to identify people who have previously been infected with the virus by looking for antibodies in their immune system.

Diagnostic tests (the sample is usually taken with a swab from the nose/mouth)

Diagnostic tests are the Antigen Rapid Test (ART) and Polymerase Chain Reaction (PCR) test that look for active coronavirus infection in the mucous or saliva. ART tests look for the coating or proteins from the virus while PCR tests detect nucleic acid (RNA), the genetic material of the virus. RNA tests are very sensitive and can remain positive even after the person has gotten better and is no longer infectious.

Antibody tests (also known as serology tests – blood tests that look for antibodies in your blood)

Antibody tests look for coronavirus antibodies in people who have been infected with the virus. Antibodies are proteins made by the immune system to fight infections. The timing and type of antibody test affects accuracy as it can take 1 – 3 weeks after infection for your body to develop enough antibodies to be detected in a test. Antibody tests are a good way to determine if you have had significant exposure to the virus in the past but should not be used to diagnose someone with an active infection, due to the delay in production of antibodies after exposure to the virus.

In Singapore, both ART tests and PCR tests are done by swabbing the back of the nose or throat to collect secretions for testing. The difference is that antigen tests can produce results in an hour or less. Due to the possibility for false positive or false negative result from the ART test, a further PCR test may be ordered to confirm the result.

A COVID-19 PCR test result can be shared as early as 24 hours after sample collection. After the person has cleared their nose, samples are taken from the back of the nose or back of the throat. The back of the nose is preferred as it contains the highest viral load. The process may feel slightly uncomfortable and might even cause one to tear up. As for an oral swab, it will be placed down the throat for 2 – 3 seconds. The sample will be placed in a secure container before being sent to the laboratory for testing.

An antibody test is usually done after full recovery from COVID-19. A blood sample will be taken by a healthcare professional via finger prick or venous blood draw and then sent for testing.

How can I get tested?

The Ministry of Health has recently approved the use of do-it-yourself, self-test kits that can be purchased at pharmacies. Designed to be self-administered, these tests will allow more frequent testing for greater peace of mind, should individuals wish to be tested more often. Anyone who tests positive using a self-test kit should immediately approach a SASH clinic for a confirmatory test, and self-isolate while awaiting results.

Click here to to find out more about our COVID-19 ART Kits.

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