New Delhi: Even as it is widely feared that Kerala could be staring at the second wave of COVID-19, the Union health ministry has alerted the state against over-dependence on antigen test instead of RT-PCR test to detect the prevalence of the disease.
On examining the data from February 10 to April 6, it has been found that the RT-PCR tests had not gone beyond 53 per cent in any stage (in Kerala). Over the last two weeks this had come down to 45 per cent, Union health secretary Rajesh Bhushan stated.
The apparent slackness of Kerala comes at a time when the Centre has directed that this of the total tests at least 70 per cent should be RT-PCR test.
RT-PCR tests had also declined in Covid-affected Chattishgarh, Maharashtra and Gujarat. However, these tests are on the higher side in Punjab, Haryana, Tamil Nadu, Madhya Pradesh and Karnataka.
Though the Test Positivity Rate in Kerala had reached 8.10 per cent at one stage, it had reduced subsequently. However, the recent data is causing apprehension, the Union health ministry said.
Last week the central government had warned that the coronavirus situation was "turning from bad to worse" and was a huge cause of worry, especially for some states.
All states and Union Territories are reporting a surge in cases and there is a need to significantly and exponentially increase the number of COVID-19 tests. The proportion of RT-PCR tests need to be increased too, the Union health secretary had said while issuing the alert.
Antigen test vs RT-PCR test
Direct detection of viral components in respiratory specimens is often made through nucleic acid amplification tests via polymerase chain reaction (PCR) or antigen-based tests. These tests are apt to detect viruses that are primarily acquired via a respiratory route, such as SARS-CoV-2 which is widely known as COVID-19.
RT-PCR denotes Reverse-Transcriptase Polymerase Chain Reaction. It is a laboratory technique.
Antigen tests have variable reliability; hence they are discouraged. They are not yet widely available.
The RT-PCR test aims to detect the viral RNA of the coronavirus. A positive result is highly specific for the presence of the virus.