Indian Council of Medical Research has approved ‘Rapid Antigen Detection Test’ which is low-priced as well as time-efficient when compared to other analyses or detention of the novel coronavirus.
It is a point-of-care test, performed outside the conventional laboratory setting, and is used to quickly obtain a diagnostic result.
On June 18, J&K’s Chief Secretary informed the Deputy Commissioners about its use for a rigorous test of the vulnerable people especially in red and containment zones.
However, depending on the viral load, the sensitivity of the rapid test is between 50.6% to 84%. In other words, those who test negative might still have the infection. At the same time, the test gives a measure to the government and those showing symptoms would be advised to go for a test through the more reliable RT-PCR method, which a diagnostic test to confirm the presence of the virus using a nasal swab in a laboratory setting. Unlike the earlier rapid antigen detection test, the new test also seeks to detect the virus rather than the antibodies produced by the body. While the mechanism is different, the most significant difference between the two is time.
As the ICMR has pointed out, the RT-PCR test takes a minimum of 2-5 hours including the time taken for sample transportation. In a reliable rapid antigen detection test, the maximum duration for interpreting a positive or negative test is 30 minutes.
If the test shows a positive result, it should be considered as true positive, and does not need reconfirmation. However, those who test negative in the rapid antigen test should then be tested by RT-PCR to rule out infection.
It also signifies that there is a need to increase capacity enhancement of hospitals to accommodate the higher numbers of symptomatic patients which might be detected using the new test. The government may find need to also shift asymptomatic patients to COVID care centres and such there is an immediate need to augment critical care.
It is important that rapid antigen detection tests are done for surveillance testing rather than to make medically important decisions. The rapid test is being utilized as part of the exit plan from lockdown. The concerned quarters are already aware that new tests cannot substitute for RT-PCR to diagnose infection.
New Rapid Test
