Context: Amid the rising cases of novel coronavirus disease (COVID-19), states have started to look at “rapid tests” — serological or blood tests — as an alternative to the longer, swab-based tests routinely being used.
About the two tests:
Polymerase Chain Reaction (PCR)
These are blood-based tests that can be used to identify whether people have been exposed to a particular pathogen by observing the development of antibodies.
It is done after taking nasal or throat swabs of the patient, from which RNA is extracted and converted to DNA, which is then amplified before being checked for confirmation of the virus.
Report comes in 30 minutes
Report comes after 9 hours.
Not possible as it takes 7-10 days for the antibodies to develop
Possible as it is a standard test for COVID -19 identification and not dependent on antibodies formation
Less efficient as after this PCR needs to be conducted anyways
More efficient as it ensures certainty of disease
Indian Council of Medical Research’ (ICMR)’s viewpoint:
- It issued an interim advisory on the use of serological tests in “hotspots”, before pulling it down hours later.
- The advisory read population in hotspot areas may be tested using rapid antibody test, and
- Antibody positives to be confirmed by RT-PCR using throat/nasal swab
- Antibody negatives to be quarantined at home
- It put up a list of approved and validated antibody testing kits that can be used directly after due approval from DCGI (Drug Controller General of India) and intimation to ICMR.
Reasons for pulling down advisory by ICMR:
- The ICMR’s contention that it is not a diagnostic test is partly because the test detects the antibodies and not the virus, which means the virus needs to have spent some time in the body.
- For that duration, the person would continue to spread the disease to others which is not an ideal situation.
- Currently, these serological tests are not recommended for diagnosis of COVID-19 infection as per ICMR.
States point of view:
- Kerala has already rolled out such tests, Maharashtra appears set to do so, while Chhattisgarh has sought permission.
- Earlier, the Tamil Nadu government had approached ICMR for permission to follow the ‘South Korea-China model” of rapid tests, but the ICMR had said the real-time PCR (RT-PCR) test is more foolproof.
South Korea Model:
- The country had shot up to the top of the COVID-19 chart in February but later emerged as a success story in its containment aggressively using mass testing, including with serological kits, to reduce the number of cases.
- The country had 9,976 cases and 169 deaths but managed to contain the virus without the kind of lockdown that several countries including India have now gone into.
- While it is testing that has got it global praise, it is also a fact that South Korea’s success was as much because of its hospital infrastructure that was ramped up during the earlier outbreaks of SARS and MERS.
- Though South Korea has become the benchmark, it was Singapore that first started using such tests.
Indian Council of Medical Research:
- It is an apex body in India for formulation, coordination and promotion of biomedical research.
- It conducts, coordinate and implement medical research for the benefit of the Society
- It translates medical innovations into products/processes and introduces them into the public health system.
- The governing body of the council is presided over by the Union Health Minister.
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