Written By: Longjam Dineshwori | Published : June 17, 2020 2:35 PM IST
The antigen test can detect presence of SARS CoV 2 in swab collected from nose alone.
In a bid to boost India's COVID-19 testing capacity, the Indian Council of Medical Research (ICMR) has approved the use of rapid antigen test kits for diagnosis of coronavirus infection in containment zones and healthcare settings in combination with the RT-PCR test.
The kits will allow faster diagnosis of infected patients at lower rates and without laboratory examinations of the samples. Each kit will cost 450 and can show results within 30 minutes as opposed to the current RTPCR test that takes 3-4 hours. RTPCR testing is also more expensive as one kit costs about Rs 2,500. Moreover, RTPCR testing method require the samples to be transported to and then examined at limited number of labs.
The Delhi government is likely to start using rapid antigen kits for COVID-19 testing in containment zones and healthcare settings from June 20, officials told a news agency on Monday. Delhi has around 240 COVID-19 containment zones and the government is planning to conduct door-to-door survey in these zones.
As of Wednesday, Delhi recoded total 44,688 coronavirus cases and the death toll due to the disease has climbed to 1,837 - as per the Health Ministry website. The top two worst-hit states are Maharashtra with 113445 cases and Tamil Nadu, which has recoded 48019 positive cases so far.
The ICMR has advised to use the rapid antigen test kits along with the RT-PCR test. In an advisory, the apex body said that suspected individuals who test negative for COVID-19 by rapid antigen test should be tested sequentially by RT-PCR to rule out infection. However, a positive test by rapid antigen test does not need reconfirmation by RT-PCR test.
According to the ICMR, the kits should be used for all symptomatic people with influenza like illness in containment zones or hotspots, asymptomatic direct and high-risk contacts with co-morbidities of confirmed cases. In hospitals, rapid antigen testing should be done for all symptomatic patients with influenza like illness, asymptomatic patients who are hospitalized or seeking hospitalization for chemotherapy and transplants or those who are over 65 years with co-morbidities, it said.
The rapid antigen test kit, also known as the Standard Q COVID-19 Ag detection kit, has been developed by a South Korean biotechnology firm SD Biosensor. It can detect presence of molecules of the pathogen that triggers immune response in an infected person. The antigen test can detect presence of SARS CoV 2 in swab collected from nose alone. Apart from the ICMR, the test has been validated by AIIMS, New Delhi.
In its advisory, the ICMR noted that the antigen test has a very high specificity (ability to detect true negatives) ranging from 99.3 to 100 per cent while sensitivity of the test (ability to detect true positives) ranged from 50.6 to 84 percent in two independent evaluations, depending upon the viral load of the patient.
The maximum duration for interpreting a positive or negative test is 30 minutes, after that the test strip should be discarded, the ICMR said.
At present, nearly 1.5 lakh RTPCR tests are being conducted in the country per day. Using the newly approved technique, India is trying to boost its testing capacity to three lakh samples per day.
