Finger prick blood tests will be used strictly as a surveillance tool for detecting Covid-19, Indian Council of Medical Research (ICMR) has said.
The first consignment of five-lakh kits from China has reached India. India has confirmed 12,759 positive cases, with 1,515 patients cured and 420 deaths. “Now that the kits have arrived, they will be deployed on the field. However, we must bear in mind that they will be used only for surveillance purposes and not for diagnosing the virus,” R Gangakhedkar, head, infectious diseases, ICMR said.
“It is not for early diagnosis of the virus, but only for surveillance purposes. We will not deploy these to test every one as of now, but follow a set protocol for testing. This is because antibodies are formed in the body nearly eight days after the person has been infected, to fight the virus. So, even if I conduct this test two weeks after the person has had infection, the test will be positive in only 80 per cent of all suspects in whom I run those tests,” he explained. Two-lakh kits from Zhuhai Livzon Diagnostics and three-lakh kits from Guangzhou Wondfo Biotech have arrived. According to sources, ICMR has bought kits from Guangzhou at close to ₹550 per kit.
Gangakhedkar said, “Companies have claimed that their tests are good and we are using them for the first time to try these on the field.” He explained that these kits test for IGG and IGM antibodies in the suspect’s blood, specific for SARS-COV2 virus that causes Covid-19. “IGM signifies that this is a recent infection, while IGG signifies that the immune system is good. We should check a suspect for both antibodies. While the sensitivity of these tests is 80 per cent and specificity is 84 per cent, this means that in 20 per cent of the suspects, tests will not show proper results,” he said.
For early diagnosis, India continues to use the DNA-based Reverse Transcription Polymerase Chain Reaction (RT-PCR) tests by collecting nasal or throat swabs, which reflect the infection within as early as two days of the person catching the virus.
According to the ICMR protocol, all influenza-like illness suspects with fever, cough, sore throat, runny nose patients in hotspots and in large migration gatherings or evacuees centres must undergo RT-PCR within seven days of illness and, in case their RT-PCR tests are negative, they must go through antibody tests, after seven days.
The Ministry of Home Affairs (MHA) official spokesperson said, till date, relief worth 418 tonnes, including transportation of medical equipment, drugs and relief material, has been carried out under ‘Lifeline Udan.’ In the light of the lockdown extended till May 3, the Ministry has also told States that the district collectors must appoint nodal officers who will be responsible for co-ordinating the arrangements for migrant labourers, and a senior officer must be made in charge of each camp.