[Ask Dr Chiu] Should I have myself tested for COVID-19?

[Ask Dr Chiu] Should I have myself tested for COVID-19?

[Ask Dr Chiu] Should I have myself tested for COVID-19?

HEALTH

2020-05-12

5  Mins Read

Despite the COVID-19 pandemic, we all have reasons to go out sometimes. It might well happen that you find yourself with flu symptoms after a night out and become so worried that you already contracted the virus. For the peace of mind, you may be keen to have a test to find out the truth. As a result, there are now different tests available in the market that claimed serve such purpose. So what are these tests and how should we choose?

There are currently two type of tests for COVID-19:

Viral genetic material (real time polymerase chain reaction RT-PCR)

Antibody test

Test method

Test method

Deep throat saliva is to be gathered and returned to the clinic or laboratory for examination. Alternatively, medical worker can pass a catheter through the nose into the throat or use a swab stick to obtain secretions for testing. PCR test is sensitive and accurate, but taking sample is complicated.

An infected person will produce antibodies to combat against the virus. Finding such antibodies in blood is the evidence that the person has been exposed to the virus. Antibody test is simple and only require one drop of blood and 15 minutes to complete. In a way, it is like doing a pregnancy test. There are now even DIY kits one can purchase.

Drawbacks

Drawbacks

Many people feel uncomfortable with the action of having a catheter or stick to probe into these sensitive areas.

The accuracy is relatively lower, with higher chances of having false negative and false positive. Medical experts in Hong Kong had advised against the use of these tests for early detection of COVID-19. With false negative, one may think they are "fine" but actually spreading the virus without knowing it. For false positive, people might seek medical attention in the hospital, only to know it was a false alarm and a misuse of the public medical resources.

Applicable scenarios

Applicable scenarios

  1. People with symptoms, such as fever or shortness of breath
  2. Contact tracing, such as checking people who have had close contact with confirmed cases, in order to identify any infected individuals early.
  3. Inbound travelers, so that we can identify any imported cases promptly.

Not suitable for early detection, limited use in community.

Either test has its own shortcomings. The key is we should do a test only with reasonable needs.

Instead of worrying about the tests, a more practical way to stay away from the COVID-19 is to be vigilant with wearing masks, performing hand hygiene and maintaining social distancing.