Testing for COVID-19: Test Performance of a Rapid Antigen Detection Test


The ICMR advisory advocates RT-PCR test for all those who receive a negative test result. However, test positives are to be considered confirmed positive without subjecting them to RT-PCR. This strategy is sound when applied to small populations. However, when scaling up to a large population of several million people, the strategy may not be completely appropriate.

COVID-19 positive status has serious social and economic consequences. In many places they face stigma and discrimination; they are placed in isolation/quarantine for 14 days or more depending on their condition. While a small number of people are able to work while in quarantine, for the majority there is loss of income coupled with large hospital bills. Against this background, one wonders about the ethics of knowingly permitting several thousands of individuals with false positive test results to be placed under quarantine.

Perhaps the best solution would be to employ only RT-PCR testing. However, the test is expensive, and has greater technical requirements. On the other hand, the rapid antigen testing kit is relatively inexpensive, can be easily scaled up, and requires lesser technical expertise. One possible compromise would be to insist on RT-PCR testing for healthcare workers instead of rapid antigen test, since their status needs to be known with certainty (else they would transmit the disease to healthy patients and create potential super-spreading events/ clusters). Let me know what you think would be a better strategy- both ethically and economically- in the comments section below.

Useful Links:

Link to article on Sensitivity:


Link to article on Predictive Accuracy (PPV, NPV):


Link to ICMR Advisory for Rapid Antigen Test (PDF):



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