COVID-19 tests , what are the different types of COVID-19 tests?
Everyone living on our planet has heard a lot about coronavirus and covid-19 , causing a pandemic that affected almost every country.
You may also have heard a lot about COVID-19 tests lately. But you may be confused With that range of tests available in the market today.Which one of these is better for me? A question everyone is asking us! Here, we discuss the three types of COVID-19 tests and make a comparison to help you know more about them.
What are the types of COVID-19 tests?
1- Antibody Rapid Test
The rapid test is an antibody test , as it detects the presence of antibodies in your blood against SARS-Cov-2, the virus that causes COVID-19.
Most tests measure both IgG and IgM, but some tests measure a single antibody.
Levels of antibodies rise and fall at different times after infection. IgG is the last to rise but lasts longest. Levels of antibodies are usually highest a few weeks after infection.
Some antibody tests need special laboratory equipment. Others use disposable devices, similar to pregnancy tests. These tests can be used in laboratories or wherever the patient is (out-patient), in hospital or at home.
The test detects one of 3 situations:
1- You are infected the coronavirus
IgM or IgM + IgG = Positive
2- Or you have been recovered from the disease
Only IgG = Positive
3- or you had never been exposed and you are liable to be infected (not immune)
Both= negative
The rapid test is an antibody test , because it looks for antibodies produced by the immune system as a response to infection.
Antibodies may take weeks or months to develop after an infection, and may stay in your blood for several weeks. As a result, these types of tests must not be used to diagnose the presence of COVID-19 in your system.
Review of studies to find out how accurate are antibody tests for covid-19
https://www.cochrane.org/CD013652/INFECTN_what-diagnostic-accuracy-antibody-tests-detection-infection-covid-19-virus
2- Antigen Test
Antigen tests detect certain proteins using nasal or throat swabs. It is able to diagnose an active coronavirus infection.
Positive results from an antigen test are very accurate if positive, but it can give False Negative results due to low sensitivity, it Cannot detect the virus in very low quantities. So, the test does not completely rule out the infection.
3- RT-PCR Test
To get the most accurate result, you need to do a swab test, which is an RT-PCR test for covid-19. This is the standard test fo covid-19, used widely to diagnose infection. It is the most accurate of the three, and typically do not need to be repeated.
The RT-PCR means reverse transcription-polymerase chain reaction. It is done by taking swabs for the nose or throat, to detect if a person actually has the virus.
