RT-PCR: The gold standard for COVID-19 testing
SHILLONG, Dec 9: The accuracy of Rapid Antigen Tests (RAT) has been questioned time and again by medical experts as there are several instances when patients who tested COVID-19 negative via RAT were found COVID-19 positive when tested through the RT-PCR.
However, Meghalaya seems to be relying more on Antigen tests rather than the RT-PCR tests for detecting COVID-19 cases.
Since the beginning of the pandemic in the state, 1,47,082 antigen tests have been conducted while the number of RT-PCR tests conducted in the state stands at 97,938 till date. Apart from Antigen and RT-PCR tests, 8,784 TRUNAAT and 6,463 CBNAAT tests have been conducted in the state so far.
Concerns over the accuracy of RAT were being raised as nearly 11 per cent of those in the national capital who tested negative for COVID-19 in the RAT had symptoms of the disease and were later found to have been infected after being put through the RT-PCR test between September 1 and November 7, according to official data.
Speaking on this matter, Ram Kumar S, Joint Secretary, Health Department, said that when a person tests positive via the RAT then the person is surely positive. Admitting that the accuracy of antigen tests is 50 per cent, he said that the government is not taking chances and is using RT-PCR tests for high risk contacts.
When asked about the re-infection of people in the state, he said that there are only about 9-10 cases where individuals were re-infected with COVID after recovering and most of them are health workers.
He also said that instances like these when patients who tested COVID-19 negative via RAT were found positive after going through the RT-PCR test is happening everywhere.
Sharing his views, NEIGRIHMS Director, Dr P Bhattacharya said that there are instances when emergency cases come to the Hospital and they have to take immediate call on whether or not to treat the patient with full COVID precautions and that is when they go for RAT since an RT-PCR test takes 6-8 hours for confirming the results.
“RAT is an emergency management,” he said while reiterating that if a person tests positive in an antigen test, then the person is sure to be COVID positive and the case is taken up with full COVID precautions and if the person is negative, they go for an RT-PCR test.
Stating that the antigen test is only done in emergency cases, he said that he is not a fan of antigen tests and ultimately it is the RT-PCR test which is the gold standard and gives a confirmed result.
Dr Bhattacharya also said that one advantage of the Antigen test is that if a person tests positive, it saves the cost and time on RT-PCR test.
Earlier on in order to effectively curb the spread of coronavirus infection, the Union Health Ministry had in September asked all states and Union Territories to mandatorily retest all symptomatic cases found COVID-19 negative in Rapid Antigen Tests through RT-PCR so that no positive case is missed.
A local doctor correctly observed that every person testing COVID-19 positive after a RAT is confirmed positive but a person testing RAT negative could well be positive after an RT-PCR test.