The Indian Council of Medical Research (ICMR) on Wednesday approved the country’s first Covid-19 self-testing kit for home use. That essentially means anyone can collect their own nasal sample and test it for SARS-CoV-2.
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Many states are going through a second wave of infections, putting pressure on diagnostics laboratories. The RT-PCR test, considered the gold standard for Covid-19 testing, takes 3-4 days to give results, delaying hospitalisation and treatment.
Self-test kits can potentially be a game-changer in Covid-19 management in India. These can cut queues in laboratories, reduce costs, dissipate the burden on existing manpower for sample collection from homes, and provide quick results (within 15 minutes), leading to prompt treatment and isolation.
Such a self-test kit was first approved in the US last November. A rapid-result all-in-one test kit produced by Lucira Health was given emergency use authorisation. Similar kits have been approved in Europe and South Korea too.
Called CoviSelf, it has been developed by MyLab Discovery Solutions, a Pune-based molecular company. It uses a rapid antigen test, in which a nasal swab sample is tested for the virus and gives results within 15 minutes. Taking the test takes hardly two minutes.
This testing kit cost Rs 250, while RT-PCR test costs between Rs 400 to Rs 1,500 and a rapid antigen test in laboratory costs Rs 300-900 in different states.
“For India, we will make millions of kits available at fraction of the cost of such kits in the US,” said Dr Hasmukh Rawal, managing director in MyLab. The kit will be available in market by end of next week. MyLab’s current production capacity is 70 lakh kits per week, and it plans to scale up to one crore kits per week in next fortnight. The kits will be available across at least seven lakh chemists and e-pharmacy portals in India, the company said.
“This easy-to-use test combines with MyLab’s AI-powered mobile app so that a user can know his/her positive status, submit the result to ICMR directly for traceability, and know what to do next in either result. We are sure this small step will be a big leap in mitigating the second and subsequent waves,” said Sujit Jain, director, MyLab Discovery Solutions.
ICMR has advised this test only for those who have symptoms or are high-risk contacts of positive patients and need to conduct a test at home. If positive, the person will be considered Covid-19 positive and will not require RT-PCR as a confirmatory test. All government guidelines for isolation and high-risk contact tracing will be followed. This test is synced with a mobile app, CoviSelf, which will help directly feed the positive case’s report on the ICMR portal. This test is not advised for general screening in public places of hawkers, show owners, or commuters.
If a person tests negative but has symptoms, he or she has to undergo RT-PCR test.
The kit comes with a pre-filled extraction tube, sterile nasal swab, a testing card, and biohazard bag. First download the CoviSelf app and enter all your details. The app will capture data on a secure server connected with the ICMR portal, where all test reports are available to government.
Before taking the test, sanitise your hands and clean the surface on which the kit is to be placed. Insert the swab into your nose 2-4 cm inside, or until it touches the back of nasal tract, and rub it well to collect the specimen. The swab is then swirled inside the extraction tube to mix with the liquid inside, the tube is tightly closed, and two drops from the extraction tube’s outlet are spilled onto the testing card.
The result comes within 15 minutes. A person is positive for Covid-19 if two lines appear on the testing card — on marker ’t’ for testing line, and ‘c’ for quality control line. If the person is negative, a single line appears on marker ‘c’. If the result takes more than 20 minutes to show, or if a line does not flash across marker ‘c’, then the test is invalid.
Seal the tube and swab in the biohazard bag and dispose of it as biomedical waste.
A person testing himself at home rather than visiting a hospital or lab, or calling a technician at home, reduces the risk of transmission to others. Swab collection in this case is fairly simple and quick, and reduces overall testing expenditure and the stress of booking appointment in labs. Self-testing will reduce the burden on laboratories that are currently working 24 hours up to full capacity with manpower that is already saturated.
On the flip side, the reliability of results remains a major concern. The likelihood of the sample not being collected correctly, or the swab stick getting contaminated, is high.
Also, rapid antigen tests come with a high chance of false negatives. If a Covid-infected person is asymptomatic and tests negative, the test may give a false sense of security. But by far the biggest concern is the difficulty in tracing positive patients. A person can feed a wrong address and details on the mobile app, making it impossible for health workers to carry out contact tracing. Alternatively, technical errors in the mobile app can hamper the entire testing and reporting process.
While a rapid antigen test serves as a quick mass surveillance tool, over-dependence on it for testing is not advisable. It should only supplement, not form, the bulk of testing.
Self-tests can be effective if the patient follows isolation norms, feeds correct data and is able to interpret the results accurately.
According to the European Centre for Disease Prevention and Control, “the reliability of the test result depends on a few factors: the ability of the person taking the sample and performing the test to follow instructions, the viral load at the time of the sampling, and the disease prevalence in the population when the test is taken”.
The European CDC released a document in March, stating self-testing can complement but not replace traditional testing methods. “Shifting the responsibility of reporting test results from health professionals and laboratories to individuals could lead to underreporting, and make response measures such as contract tracing and quarantine of contacts even more challenging,” the report said.
But a preprint in MedRxiv by three US researchers from Harvard and Yale argued that home testing could actually help in pandemic control and warrants being considered as part of national containment strategy.
Another article, in The New England Journal of Medicine last September, said simple, cheap rapid tests will accomplish the aim of mass surveillance even if their sensitivity to capture accurate results are inferior to other tests.