The Calcutta Municipal Corporation will conduct rapid antigen tests in housing complexes if residents request for the tests, Firhad Hakim, the chairman of the CMC’s board of administrators, said on Saturday.

Residents, though, have to ensure at least 20 people would undergo the tests. They must provide an AC room to conduct the tests, Hakim said.

A request for the tests can be WhatsApped to 9830037493. There will be no charges for the tests.

Civic officials will get in touch with the sender of the message and fix a date and time for the tests.

“We have decided to conduct rapid antigen tests at housing complexes if at least 20 people agree to undergo the tests. Residents have to provide an AC room to conduct the tests… it is very difficult for a medical technologist to conduct the tests wearing a PPE in this weather,” Hakim said at the civic headquarters on Saturday.

“The need of the hour is to conduct more tests so that those who test positive can be isolated,” he said.

Conducting tests on a few people will be a waste of logistics; so, the minimum requirement of 20 people for the tests, a CMC official said.

The civic body can conduct the tests in a locality as well if residents can provide an AC room and there are at least 20 people interested in taking the tests, the official said.

The rapid antigen test is conducted to detect the presence of the novel coronavirus (SARS-CoV-2) in a person’s nasopharyngeal swab sample. The results arrive within 30-40 minutes whereas it takes one or two days for an RT-PCR test result.

But the rapid antigen test is known to produce false negatives, which means someone who tests negative can actually be Covid positive.

A symptomatic person who tests negative should undergo an RT-PCR test to confirm if she/he is actually negative, according to the Indian Council of Medical Research guidelines for rapid antigen tests.

An asymptomatic person who tests negative in the antigen tests should be considered as not infected, the ICMR has said. Someone who tests positive need not undergo further tests and should be considered as Covid positive.

Despite its deficiency, the ICMR has okayed rapid antigen tests because the results are available in 30 minutes. “Someone who tests positive in the test can be isolated soon.

He/she will be asked to stay isolated at home if symptoms are mild. If such a person keeps mixing with others, he/she can spread the virus to more people. This is one of the reasons why antigen tests are being done,” a CMC doctor said.