The Centre on Friday said that the reverse transcription–polymerase chain reaction (RT-PCR) tests for detecting coronavirus do not miss its variants. The health ministry, in a release, said that the “sensitivity and specificity” of RT-PCR tests remain the same despite the emergence of mutant strains of the coronavirus.

The clarification came amid concerns, including those raised by media reports, that RT-PCR tests were failing to detect new variants of the virus.

“The detection of these mutations does not change the strategy of management which remains to test, track, trace and treat,” the health ministry stated.

The health ministry added that so far 17 mutations of the virus from the United Kingdom, 17 other from Brazil and 12 from South Africa have been found in India and many other countries. These variants have shown higher transmissibility, the ministry said.

The release also stated that a double mutation of the virus has been found in countries like Australia, Belgium, Germany, Ireland, Namibia, New Zealand, Singapore, United Kingdom and the United States, adding that the higher transmissibility of this variant had not been established yet.

The Centre did not mention about the presence or spread of the double mutation variant in India, even as reports quoting data from the National Institute of Virology in Pune have suggested that the strain was found in 61% of the Covid-19 samples taken from Maharashtra between January and March. The country’s principal scientific adviser has also said recently that the double mutant type of the coronavirus can be considered a “variant of concern”. The United Kingdom on Friday said that the country has recorded 77 cases of the double mutant strain that was first detected in India.

After the National Institute of Virology data was placed before them, health officials in Maharashtra said that the Centre was yet to inform them if a different strategy was needed to tackle the variant. The Maharashtra government said that they had not received any written report on the mutant strain and the data was shared verbally by the National Institute of Virology.

However, in Friday’s release, the Centre claimed that the Indian SARS-CoV-2 Genomics Consortium, or INSACOG, a network of 10 laboratories was continuously monitoring the genomic changes in the virus in India. It added that INSACOG guidelines were shared with states, which were also advised to send samples for genome sequencing along with clinical data of positive persons.

“However, several states, including Maharashtra, Madhya Pradesh, Rajasthan and Kerala have not shared such data, though others including Punjab and Delhi have,” the central government said.