Despite accuracy concerns, Chandigarh to introduce antigen test

Naina Mishra

Tribune News Service

Chandigarh, July 29

The UT Administration is set to introduce the rapid antigen test for the first time for the diagnosis of Covid-19.

According to sources, the UT will procure around 2,000 kits in the coming days. A tender has been floated on the GeM portal.

The UT will use the antigen test for asymptomatic patients only. Those who test positive will be considered Covid patients. As per the ICMR advisory, symptomatic patients with negative antigen results have to go in for the RT-PCR test for confirmation. However, no RT-PCR test confirmation is required for asymptomatic individuals testing negative in the antigen test.

However, the antigen test has been widely condemned for its low sensitivity as compared to the RT-PCR test. In its advisory, the ICMR said it had evaluated the antigen kits’ performance in two labs and had found its sensitivity to be 50.6 per cent and 84 per cent.

Recently, the Delhi High Court had asked the Delhi Government why it was going in for the rapid antigen test, which had a high rate of false negative results, as the primary test for Covid.

An official said on condition of anonymity, “The antigen test at times gives a false negative result and warrants confirmation using the RT-PCR test. Around 90 per cent of the tests had to be repeated using the RT-PCR method in line with the previous ICMR advisory.”

The decision to start the rapid antigen test was taken on the advice of the PGI authorities, who apprised the UT Administrator on its feasibility.

Know the difference

• Real-time RT-PCR is the gold standard front line test for diagnosis of Covid. The time taken for the test varies from two to five hours, including the time taken for sample transportation.
• Known as the Standard Q Covid-19 Ag kit, the antigen test does not require any specialised machine. The test can be interpreted as positive or negative after 15 minutes of using the sample. It can be read with a naked eye. The maximum duration for interpreting a test is 30 minutes.