As India looks to ramp up testing in light of migrant movement and easing restrictions, an indigenous TB test will help in increasing the rate of testing.
The Indian Council of Medical Research (ICMR) has recommended the TrueNat COVID-19 test. Until now, the test was used only for screening COVID-19 suspect samples. Now, it can also be used as a confirmatory test. The test will be used in two steps — first for screening, as a E gene screening assay for all COVID-19 suspect samples, followed by the second step for the RNA-dependent RNA polymerase (RdRp) gene based confirmatory test in all E gene positives, the ICMR has said.
Prior to COVID-19, the ICMR had validated the indigenous TrueNat test for tuberculosis. The molecular test can diagnose TB in an hour and test for resistance to the drug rifampicin, too. “The test is WHO pre-qualified and is included as a reliable and accurate method for quick screening of TB patients. The TrueNat assay has also been validated by ICMR-NIV as a point of care test for Nipah virus disease,” the ICMR said.
The TrueNat platform comprises of a TrueNat machine, inbuilt RNA extraction system, RT-PCR chips, collection swabs and viral lysis medium (VLM). “A single test has a turnaround time of 35-50 minutes for 1-4 samples with a total of 12-48 samples being tested per day, depending upon the type of machine,” the ICMR said in a statement. The biosafety and biosecurity requirements are minimal because the sample is collected in viral lysis medium (VLM), which inactivates the virus. The test can be used at the level of district hospital and primary health centers as well.
In April, the indigenous manufacturer, Molbio Diagnostics, developed the TrueNat test for screening of SARS-CoV-2 and after validation, several states started using it for detection. “From April 2020, more than 1.3 lakh screening tests have been conducted by the states. However, the limiting step has been the lack of TrueNat confirmatory test. All the TrueNat positive samples had to be confirmed by RT-PCR-based tests either located in the same or different laboratory,” the ICMR said in a statement. The validation for screening and confirmatory test has been done by the department of health research/ICMR Virus Research & Diagnostic Laboratory (VRDL) at Bangalore Medical College & Research Institute.
The biosafety and biosecurity requirements for the TrueNat are minimal in view of the sample being collected in viral lysis medium (VLM), which inactivates the virus. The test can be used at the level of district hospital/primary health centers as well.
“As the COVID-19 pandemic is expanding, there is a global shortfall of diagnostic supplies. It is critical for countries to strengthen indigenous production of diagnostic material to ensure uninterrupted availability,” the ICMR said. The initial few weeks were challenging in accessing and stockpiling diagnostic kits to meet the domestic demand, the ICMR added. Eleven indigenous RT-PCR kits have been validated and recommended for testing.