The Indian Council of Medical Research (ICMR) said today that while 4,49,810 tests of coronavirus had been done so far and more than 35,000 tests were done yesterday, in view of the complaint from Rajasthan, it has asked the state not to use the rapid test kits for two days.
These rapid antibody-testing kits have come from two Chinese companies Lieozon and Wanflo. India strangely continues to be friendly to China amid worldwide condemnation of the communist state’s fishy behaviour in allegedly spreading the contagious disease across the globe.
Dr R Gangakhedkar of the ICMR said that 29,776 samples had been tested in 201 laboratories of the council’s network and remaining 6,076 samples had been tested in 86 private labs.
Dr Gangakhedkar said the ICMR had distributed rapid test kits in all the states, but one state said that there was some problem. Rapid and RT-PCR tests differ, he said.
“We have, therefore, said that states should not use this test kit for the next two days while we work on the drawback. After an examination, we will ask the company for replacement. We will investigate for two days and issue directions after investigation,” Dr Gangakhedkar said.
“It is a new disease. In the last three-and-a-half months, science has progressed and developed PCR tests. Five vaccines have gone into human trial phase out of 70 vaccine candidates. It has never happened before in case of any other disease,” Dr Gangakhedkar said.
ICMR explains the difference between RT-PCR and rapid antibody testing
In reverse transcription Polymerase Chain Reaction (RT-PCR), First, a sample is taken by swabbing the nasal passages or throat. To find evidence of the virus, researchers use PCR to copy and amplify any segments of viral genetic code found in the sample, which makes it easier to detect. This typically involves adding reagents and enzymes and raising and lowering the temperature of the mixture, known as thermal cycling.
The software then determines when the number of copies of the target sequence exceeds a threshold, indicating if the novel coronavirus is present, and at what concentration.
In contrast, “Serology kits are better known as rapid testing kits. If the infection enters my body, I will be able to see the virus on the nasal swab and the pharyngeal swab. If I wait for eight days, I will see symptoms because the presence of the virus will be the most in my throat and nose. Then it [the presence of virus] starts falling,” Dr Gangakhedkar had explained on 16 April.
He added, “If the virus enters my body, my body will prepare a weapon to fight this virus which is known as antibodies. Antibodies are exactly the opposite of the virus which is why it disables the virus. There are types of antibodies, the first of these is IgM (immunoglobulin M) which does not stay for more than a few days. Detection of IgM antibody means that the infection is recent. When the IGG antibody appears, I will know that my immune system is improving. If I see only IGG antibody and no IgM antibody, I can assume that this is an old infection.”