‘All-gene RT-PCR test can catch new Covid-19 strain’

By: Vivek Tripathi

Lucknow: Umesh Singh of Lucknow, who runs a pharmaceutical company, had symptoms of coronavirus four days ago when he got his Reverse transcription polymerase chain reaction (RT-PCR) test done but the report came out negative. When his condition continued to deteriorate, he quarantined himself and got himself tested again. The report came out negative but he is currently undergoing treatment at home.

Similarly, Ankush Tripathi of Lucknow showed early signs of Covid-19. He underwent an RT-PCR test whose report turned out to be negative. His health condition also did not deteriorate much. He experienced a sore throat and difficulty in breathing. At present, he is currently undergoing treatment while in home quarantine. He is slowly recovering from the infection.

The new strain of virus during the second wave of the pandemic is completely different from the first. People are experiencing Covid symptoms but the test report is negative. Whether it is the Rapid Antigen test or the RT-PCR test it is difficult to catch hold of the virus.

Ram Shankar Upadhyay, Chief Executive Officer (CEO) of Lexai Life Sciences Pvt. Ltd., Hyderabad, and chief scientist of Om Oncology, US, said, “The new strain that has come in is hard to detect during testing. The patient’s sample should be taken properly. To take the sample, a trained person should take both nasal samples. Samples should be taken from inside the nasopharyngeal cavity in the nose. A sample stick cotton should reach the oropharyngeal cavity to take out a sample in the mouth. In addition, the sample stick cotton should be rotated for three to four seconds. If the sample is not taken properly, it would be extremely difficult to identify the infection.”

He said, “The design of the earlier RT-PCR kit was in line with the virus pattern during 2020. Now the genetic structure of the infection has changed. Due to this a lot of infected cases will not be detected. Even before, the accuracy of an RT-PCR test was 80 per cent. As much as 20 per cent false positive or negative reports were found. This accuracy has further slumped. A lot of viruses have changed. The RT-PCR test will have to be updated if one needs to find it out.”

“All-genes RT-PCR test will have to be done for that purpose. O, R, S A, B, R are all types of genes. Suppose someone is vulnerable to the new virus, he undergoes an RT-PCR test. If the virus is in the ‘S’ gene, the RT-PCR test will not show anything, in this case the chances of confirmation of virus in the report will be reduced. Instead, if we will do an all gene RT-PCR test, even if there is a virus in any gene, it will be detected. Later, the virus will change its shape. The government laboratories should be upgraded. Regular genome sequencing surveillance should be continued. From this, it will be known how the mutation in the strain is inside the people. People will become aware before this strain spreads among them and the RT-PCR kit will also be updated. Government laboratories should continue to make efforts to increase genome and serological surveillance within the country. Gene RT-PCR test should cost between Rs 700-Rs 1,000.”

Upadhyay has been an Assistant Professor at Uppsala University, Sweden, for over a decade and has also worked in Max Planck Germany (Berlin) and Medicinal Research Council, UK (London), Ranbaxy and Lupine.

Dr Sheetal Verma of the Department of Micro Biology, King George Medical hospital, says, “There are many different types of kits available. I am testing a variety of genes. The old kit is being tested. There are no guidelines on how to change the kit right now. It has been seen in some patients that their report is negative on undergoing RT-PCR test. But they still have symptoms of Covid-19. They can be treated for coronavirus by undergoing a CT scan and placing them in some different areas.”

“If the RT-PCR test is negative and if the symptoms of coronavirus are present then the way of taking the sample will have to be changed. The infection is at a very low level. The risk of spreading to others is less. Samples are now being taken from the people’s throat but it also needs to be taken from mucus as well. The decisions related to the testing and kit are issued by the Union Health Ministry and the Indian Council of Medical Research. No institution can implement it on its own behalf.”

Related Articles