The rising number of Covid-19 cases have attracted some of the private hospitals and clinics to carry out screening test for outpatients. It is important to note that some of these centres are offering Rapid Tests (RTK), which is not the same as Polymerase Chain Reaction (rRT-PCR) test which is being advocated by the Malaysian Ministry of Health.
rRT- PCR is able to detect the disease early because it detects the presence of the Covid-19 virus in the body. This test is highly accurate, but the drawback is it takes slightly longer to process and is more costly.
RTK however, detects the disease late because it detects the response of the body to the Covid-19 as it produces antibodies against the virus. This test is not accurate during the early phase of the disease and may show a negative result although the patient is actually sick and contagious. This is very dangerous as patients might be falsely reassured that they are well. Sadly, this test is currently being marketed by those who want to make a quick buck because it is cheaper and gives the test results in a short time, although its accuracy is questionable.
Here I have tabulated a summary of rRT-PCR vs. RTK Covid-19 test:
So, as I have highlighted in the table above, these 2 types of tests have their own pros and cons.
The RTK is not a suitable test for diagnosis and early detection of the Covid-19 disease. Probably in the near future it can be used to detect the efficiency of a Covid-19 vaccine to create an immune response or to determine if someone has been exposed to Covid-19 virus in the past.
The current RTK for Covid-19 is mass produced by many manufacturers, and its quality and reliability is still questionable.
So, for now the simplest take home message about Covid-19 testing is:
Please spread this message to your family and friends. Please choose wisely. I trust you will make the right choice.