As media outlets are on their toes to report the latest development of the COVID19 pandemic, we are constantly bombarded with information about different tests that are available to detect for the presence of SARS-CoV2 (the coronavirus that causes COVID-19 disease) infection. There are currently two tests that are performed by clinical laboratories, clinics and hospitals in Malaysia. These tests are the rt-PCR (Real-Time Reverse Transcription Polymerase Chain Reaction) and the RTK (Rapid Test Kit).
What Is The Difference Between rt-PCR and RTK?
The rt-PCR (Real-Time Reverse Transcription Polymerase Chain Reaction) is done in the medical laboratory to directly test for the presence of COVID19 viruses in the human body. This test is performed by a healthcare professional taking a swab from the nose (nasopharyngeal) and throat (oropharyngeal) from the individual. The tip of the swab is made with a soft fabric material (normally rayon or Dacron), similar to a cotton bud, and it is inserted into the nose or mouth and gently touches the back of the nose or throat. This method of collecting the virus sample does not cause injury to any part of the body. The swab is then sent to the medical laboratory and a PCR machine runs the test. A positive result indicates the presence of the COVID19 virus. The test result is highly accurate in determining if a person is infected with the COVID19 virus.
The RTK (Rapid Test Kit) tests for the presence of COVID19 antibodies (not the virus itself). Antibodies are developed by the human immune system to fight against bacteria and viral infections. The antibodies will remain in the body even after the person has recovered from the infection. Antibodies against the COVID19 virus will be developed between five and eight days after the virus enters the body. During this period, an infected person will be tested negative when using the RTK method and still be able to infect other healthy individuals. The RTK requires a drop of blood; similar to how a blood sugar test is done at home. This method of testing requires a skin puncture to obtain blood and this leaves the individual exposed to the possibility of infections and blood borne diseases. A positive test result means the individual has been exposed to the COVID19 virus. However, that does not mean the virus is still in the body. The body’s immune system could have fought off the infection and the antibodies are there to protect against future infections. A negative test result does not mean that the individual is not infected because it takes between five and eight days for the development of the antibodies.
Which Test To Perform?
Both tests have important roles to play in identifying individuals affected by the COVID19 pandemic. The rt-PCR test can determine if a person is currently infected, whereas the RTK method can ascertain if the person’s immune system has developed immunity against COVID19.
Although both rt-PCR and RTK are important tests, during this crucial moment of the COVID19 pandemic the Malaysian Minister of Health has recommended rt-PCR for early detection of COVID19 (New Straits Times, 24 March 2020). Early detection allows treatment to be provided to the infected patients as soon as possible, as well as contact tracing to identify other individuals that may be infected.
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