Although the State’s COVID-19 Technical Advisory Committee (TAC) recommended procurement of ICMR-approved OmiSure test kits for quick detection of Omicron in Karnataka, the State Government is yet to take a call on it.
This indigenous kit, developed by Tamil Nadu based TATA Medical and Diagnostics Limited (TATA MD), is a version of RT-PCR that detects all variants of SARS- CoV-2 virus like Alpha, Beta, Delta, Gamma and also Omicron. The Indian Council of Medical Research (ICMR) approved it on December 30, 2021.
“This kit can detect the Omicron variant by combining S-gene target failure (SGTF) and S-gene mutation amplification (SGMA). The sensitivity is 100% and specificity 99.25% for Omicron, and nearly 100% for all other variants. This kit can be considered for regular SARS- CoV-2 diagnosis for all variants including Omicron that is now known to be driving the third wave of the pandemic in the State,” stated the TAC’s report dated January 15.
“The kit can detect all sub- lineages of Omicron such as BA.1, BA.2, and BA.3. This is a clear advantage over existing S-gene dropout kits which are known to miss these sub-lineages. ,” the report said.
“This test kit is cost effective as the MRP per test is ₹250 plus taxes. However, the cost comes down when higher volumes are used. When the volume of the order is 5 lakh tests, it is ₹200 plus taxes per test and if it is 10 lakh test order it is ₹175 plus taxes per test. Cost per kit will depend on pack size,” the report stated.
TAC chairman M K Sudarshan said genome sequencing may not be required for Omicron positive samples in the kit as it has shown 100% concordance to sequencing in evaluation by ICMR. “In fact, samples that are negative for Omicron in this kit but positive for SARS CoV- 2 should be prioritised for sequencing as they may indicate other variants/new sub -lineages of Omicron / emergence of a new variant.,” he said.
V Ravi, former head of Neuro Virology at NIMHANS and head of Research and Development at TATA MD, said the kit will either show ‘SARS-CoV-2 present, Omicron detected’; ‘SARS-CoV-2 present, Omicron not detected’ or ‘Negative for SARS-CoV-2’. “Samples that show SARS-CoV-2 positive and Omicron not detected can be genome sequenced to detect the variant thereby making sequencing more focussed,” he said.
Pointing out that technology allows to upgrade the kit as and when new mutations occur in Omicron, he said: “Every day we look at global sequences of Omicron and if new mutations are found, the kit is upgraded. In other words, it is continuously keeping in pace with newer mutations.”
State Health Commissioner D Randeep said a proposal to procure 2,000 OmiSure kits has been submitted to the government following TAC’s recommendation. “We are yet to get the approval. We have proposed to procure a minimal number as of now for use in international passengers at the airport. If found useful, we can go for more,” he said.
