Gurugram conducts more than one lakh antigen tests since June, shows dataUpdated: Sep 21, 2020, 23:16 IST
More than one lakh rapid antigen tests have been conducted in the district till now, as per the data shared by the district health department. Since June 24, when the first antigen test was conducted in Sadar Bazar, the district health department has conducted a total of 1,00,009 antigen tests till Sunday, while on Monday 1,004 additional tests were administered in both government and private facilities. Health officials, however, clarified that the target is to keep antigen testing below 40% of the total number of tests administered in a day.
Till now, at least 2,31,468 tests have been administered in the district since the pandemic, including both antigen and the Reverse Transcription Polymerase Chain Reaction (RT-PCR) test.
Health officials said that in compliance with the revised guidelines issued by the Indian Council of Medical Research (ICMR) in the first week of September, the focus is on increasing the RT-PCR tests overall, while restricting the antigen tests largely to containment zones.
Dr Virender Yadav, chief medical officer, said, “Rapid antigen test is a useful diagnostic tool for mass survey and active surveillance especially in containment zones. As per the ICMR guidelines, the population in areas having widespread transmission of infection should be tested through antigen testing kits for early detection. In other scenarios, RT-PCR is being administered as it is easily accessible and more accurate. We are going with 60:40 ratio to keep a check on spread of infection.”
According to Yadav, for the last one month 38% antigen tests are being conducted regularly, while 62% RT-PCR is administered. On Monday, out of the 3,001 tests, 1,997 RT-PCR and 1,004 antigen tests were conducted. “Antigen tests will remain below 40% as it is restricted to only Covid-19 affected areas,” said Yadav.
The antigen diagnostic test detects proteins attached to coronavirus or within it by testing the sample collected from the nasal cavity using swabs. One of the advantages of the antigen test is its speed as it delivers the results in 15-20 minutes. However, it may not detect all the active infections as it is not as sensitive as the molecular RT-PCR tests. It means positive antigen test result is accurate, but there are chances of false negatives as well. Therefore, the negative results have to be confirmed through RT-PCR, especially in symptomatic cases.
Data shows that of the one lakh antigen tests, only 2,766 were confirmed true positive. “The positivity rate of antigen testing is almost 2.8%. To ensure active cases are not missed, nearly 13,000 antigen negatives were administered RT-PCR, out of which almost 800 people were confirmed Covid-19 positive. RT-PCR is conducted in only those cases where the person is symptomatic yet negative for the antigen test,” said Dr Jai Prakash Sharma.
On the other hand, private labs are doing almost negligible number of antigen tests compared to government facility. Every day, less than 100 antigen tests are being conducted across the seven private labs in the city. On Monday, only 83 tests were conducted in private facilities. According to lab representatives, as reported by HT earlier this week, antigen test is not preferred due to false negatives. Following up with such patients also becomes challenging if they come without a prescription.