Detection of COVID-19 virus : Comparison of several types of COVID-19 test

 In previous posts we have covered many bioanalytical techniques used to detect the COVID-19 virus from patients. These tests have been very useful to help doctors and scientist to discover more about the nature of the virus. We can see the numbers of recovered patients increasing as time pass by. But what are the differences between these tests and which test is actually the BEST? Lets find out! 

Comparison of several types of COVID-19 tests

              

	Rapid serology antibody  test	ELISA	RT-PCR swab test
Sample output	Serum or plasma sample (whole blood or finger prick also possible)	Serum or plasma sample	Nasopharyngeal or Oropharyngeal swab sample
Result output	Detection of IgM and IgG antibodies via colour change of strip in lateral flow assay	Detection of IgM and IgG antibodies via colorimetric assay	Detection of viral Covid-19 RNA cDNA sequencing
Strengths	Very low relative cost, can be conducted at point-of-care or at home, fast result (5-15 min, highly accurate detection of IgM & IgG several days after onset)	Robust detection of serovonversion status in laboratory setting, can detect IgM & IgG highly accurate several days after onset or sooner	Gold standard diagnostic test, directly detects virus presence(sequencing viral nucleic acids) most accurate results
Limitations	Requires rigorous testing of cross-reactivity with other immune response, variation of test specificity and sensitivity	Requires rigorous testing of cross-reactivity with other immune response	Labor intensive, requires numerous additional reagents and equipment, can loose accurancy after 5 days since system onset.

In this differentiation, we can see that both serology test provide fast and safe laboratory techniques but it does not mean that these techniques are accurate in determining the infection of COVID-19. From our observation, we concluded that RT-PCR swab test method is the best and the most sensitive technique which can deliver a reliable diagnosis for COVID-19 infections. The timing of conducting the tests however is crucial to avoid false-negative results. Compared to both serology test, RT-PCR significantly has lower potential of contamination as the entire process can be carried out within a closed tube. It is considered to be the gold standard and most accurate method available for the detection of COVID-19 according to WHO and CDC guidelines.

However, each test has its own distinct advantages and disadvantages inherent to the underlying technology. A combination of these tests may be helpful for patients management and population pandemic control of COVID-19.