New Delhi: The Indian Council of Medical Research (ICMR) does not maintain a database of the specific number of rapid antigen tests (RAT) and RT-PCR tests being administered for Covid-19 at the national level or across states, the apex medical research body has revealed.
Responding to an RTI query by ThePrint about the break-up of specific tests administered in 10 states, including those with the highest caseload, the ICMR said, “Information is available in cumulative form and ICMR publishes testing data in cumulative form in official website.”
Speaking to ThePrint about the process that is being followed currently, a senior official with the ICMR said maintaining specific data is the responsibility of the states.
“Laboratories across the country have a common portal. As testing is happening, they are filling up that portal. At ICMR, we have access to the portal and we are collecting and capturing this data. But whether they are doing the antigen tests or RT-PCR tests, that is the state government’s responsibility,” said the official who didn’t wish to be named.
“The data being captured is giving you the exact picture of the total number of tests being done by a particular institute on that day,” he added.
According to ICMR’s Covid testing strategy, states can choose to administer either RAT or RT-PCR tests in containment zones, screening points, non-containment areas and hospital settings.
But ICMR’s policy has come under much scrutiny as states across the country are increasingly opting for RAT.
A RAT produces a positive or negative result within 30 minutes but is low on sensitivity i.e. its accuracy to detect a positive result is about 50 per cent. Meanwhile, the RT-PCR or the reverse transcription-polymerase chain reaction is the gold standard of testing which has a sensitivity of at least 80 per cent.
Commenting on the lack of specific data, renowned virologist Dr Shahid Jameel said, “There is absolutely no reason why figures for both tests should not be released separately. Given concerns about the use of a very large proportion of RAT tests, there is certainly a policy aspect to understanding how the known sensitivity and specificity of these tests might impact our ability to identify cases correctly.”
India has so far reported more than 85 lakh cases and 1,26,611 deaths.
‘Raw data but no reports’
When an authorised testing centre administers a RAT or RT-PCR, the technicians have to record it with the ICMR using the RATI (Rapid Antigen Test of India) or RT-PCR applications. The two applications have been developed by the National Informatics Centre under the Ministry of Electronics and Information Technology (MeitY).
ThePrint reached a MeitY official, who said that while the NIC has developed the portals, only ICMR can access them. “This data is visible in the ICMR-designated labs… Even though the application is being hosted by NIC, the data is controlled by ICMR. They have the username and password,” said the official, who didn’t wish to be identified, in a telephonic interview.
“If you have raw data, whatever reports you want to generate you can generate, if you are a technical person,” he said.
A second ICMR official confirmed that the data is being stored in the cloud and reports are generated as and when a higher authority requires it. “For research purposes, we can cull out the data and make the report,” he said.
Asked if the ICMR regularly generates reports on the two tests, he said, “The ICMR doesn’t use this, it’s the state authorities who use this. We just keep data on the cumulative tests.”
Some states collate specific data
ThePrint analysed the daily Covid bulletins released by the health department of 25 states and six Union Territories, which were accessible.
It was found that nine states and one UT release specific data on RAT and RT-PCR.
Of these, Kerala, West Bengal, Manipur, Mizoram, Nagaland and Tripura have released specific data on the number of antigen and RT-PCR tests conducted till date.
Ladakh, Himachal Pradesh, Karnataka, Andhra Pradesh and Delhi have released the numbers of daily RAT and RT-PCR tests conducted.
Tamil Nadu is seemingly the only state where the RAT is not being used.
On Thursday, Health Minister Harsh Vardhan pulled up the Delhi government for a “highly skewed RAT-RT-PCR ratio (of) 77 per cent and 23 per cent”.
According to Lakshmanan S, the National Health Mission director of Assam, a state which does not release specific testing data, there was no particular reason for why separate RAT and RT-PCR data isn’t released.
Asked if this data has been helpful in the public health response, he said, “It doesn’t matter much, there are multiple mechanisms. We had 25,000 RAT tests yesterday of which 253 number of positive patients (1.7 per cent) and then we had 2,900 RT-PCR of samples taken one or two days earlier.
“Out of this, we had 50 number of positive i.e. almost 2 per cent …RT-PCR being gold standard what I’m finding is that we are not getting a huge significant difference between it,” said Lakshmanan.
According to him, a combination of 70-80 per cent RAT and 20-30 per cent RT-PCR tests is what is preferable.
Effect on Covid policy
The first ICMR official quoted above maintained that the lack of distinct data on the tests did not hinder the government’s Covid response. The Ministry of Health, which funds the ICMR, is also reliant on this data.
“There are no difficulties … Actually the antigen test is just a supportive testing in case you want to test a large number of samples for containment zone and other large gatherings,” the official said, adding that the test was also helpful as it takes less time. He further argued that ICMR policy mandates that a sample be tested by the RT-PCR method if a patient had tested negative on the RAT despite being symptomatic.
“Antigen testing is giving you an extra tool to enhance and expand the testing, but you should not rely on the antigen test,” the official said referring to the test’s low sensitivity rate.
However, the official added that states generally opt for a 60-40 per cent combination of RAT and RT-PCR tests, indicating the increased emphasis on the former.
However, some experts disagreed with this position.
“If 100 true positives are tested, RT-PCR will pick 80 and RAT will pick only 50. Now if the fraction of tests deployed vary, for the same 100 true positives you will get variable numbers of positives based on the scenario,” said Dr Shahid Jameel, who heads the Trivedi School of Biosciences at Ashoka University.
“If we don’t know the fraction of each type of test deployed, and if this ratio varies in time and space, we will not even know the real trends let alone the true numbers. Trends are important for making policy,” he added.
Meanwhile, Dr Jacob John, virologist and former professor, Christian Medical College, Vellore, was of the belief that maintaining this data isn’t as important as it will be of no benefit in individual cases.
“Knowing the attitude of doctors, if they suspect moderate to severe disease with oxygen levels, they will ignore the negative test, particularly if it’s an antigen test. They will treat the person as Covid anyway. This will not be counted as Covid,” he said.
However, Anant Bhan, a researcher in global health and bioethics, argued that specific data on RAT and RT-PCR tests would help in framing policy.
“This is the kind of data that should be publicly available, there is no reason to not share that … Rather it would help policy making, as we can gauge if a fair number of cases are being missed out because of rapid antigen tests,” he said, adding it would be valuable especially now given the festive season, winter season and pollution — all “conducive factors for the spread of the virus”.