The civic health clinics in all 144 wards of Calcutta will have the facility to conduct the rapid antigen test for Covid-19, officials of the Calcutta Municipal Corporation (CMC) have said.

The officials said a spike in the number of Covid-19 cases across the city had prompted the civic authorities to decide to start conducting the test, which produces results much faster than the conventional RT-PCR test for the coronavirus disease, in all civic clinics.

“Widespread antigen tests will lead to faster detection and isolation of infected people,” a CMC official said.

Public health specialists have repeatedly stressed that in the absence of any drug or vaccine for Covid-19, the best way to combat the disease is to test and isolate as many infected people and as quickly as possible.

To start with, the test will be introduced in the clinics of the first 100 wards in the city. The remaining 44 will be gradually added to the list.

The CMC now organises camps for the antigen test at various locations on specific days. But once all civic health clinics offer the service, people can get themselves tested on all days the facilities remain open.

“Just like conducting dengue and malaria tests, our health clinics will conduct the Covid-19 antigen test,” a CMC official said.

The antigen test is known to throw up false negatives but the Indian Council of Medical Research has still approved it because the results arrive within half an hour. The results of the conventional RT-PCR test take about two days to come.

“A person who is suffering from Covid-19 is isolated within 30 minutes if she/he tests positive in the antigen test. This helps prevent spread of the infection more effectively,” the CMC doctor said.

To deal with the problem of false negatives, the ICMR has said that people who test negative in the antigen test but have symptoms of Covid-19 must undergo the RT-PCR test. Those who are asymptomatic and test negative in the antigen test should be allowed to go.

The CMC, which launched the antigen test late last month, had earlier thought about opening antigen test centres in at least three places in each borough.

Air-conditioners will be fitted in at least one room in all the clinics where the antigen test will be conducted. The AC rooms are needed because medical technologists who will conduct the test will have to wear personal protective equipment (PPE). Working in a non-AC room wearing a PPE suit is not impossible, an official said.