When it comes to the fight against the novel coronavirus more and more states in India are set to opt for “rapid tests” instead of the traditional swab-based procedures, despite the controversy surrounding its efficacy, in order to considerably increase the pace of testing and test more people with fewer symptoms.
This after South Korea, which sat atop the world coronavirus charts in early February managed to avoid a nationwide lockdown and set a model for other states by moving aggressively to contain the pandemic through a mass rapid testing strategy, among several other measures.
The 500,000 kits, which arrived in New Delhi on Thursday morning, will be used to test people with fever, cough, and shortness of breath in 325 districts that are currently unaffected by the coronavirus, starting with those that are in states with a high number of COVID-19 cases, an official told Hindustan Times.
Calibrated approach falls by wayside
India at the outside of the coronavirus outbreak, adopted a “calibrated” approach to testing, with only symptomatic people in quarantine, health workers and contacts of positive cases being tested. As of today, only 85,000 people have been tested across India even as Kerala, Delhi, Maharashtra and Tamil Nadu, among other states, have been pushing the Centre to adopt the “Korea model” over the past few weeks.
Indeed, it was Kerala, which has done a remarkable job fighting the coronavirus, that was first to implement the rapid tests in early April after receiving approval from the Indian Council of Medical Research (ICMR) on 30 March.
Kerala, which has a strong healthcare system and instituted a slew of other measures, including contact tracing and cooked meals, has seen a mere 395 cases and just three deaths, placing it at 10th position in terms of the number of cases across all Indian states.
Compare Kerala’s success to Maharashtra, which has 3,205 positive cases and 194 deaths, and has seen an explosion of coronavirus cases over the past few weeks, and whose officials admit their fight against the disease “got off on the wrong foot”.
“Unlike Kerala, we start testing late,” an official told Economic Times. Kerala began testing in January itself at its airports and they aggressively practised home quarantine even for those who came from the Middle East countries, even before the Gulf countries were not included in the initial list of countries that needed compulsory quarantine.”
While Maharashtra is set to roll out rapid testing after the all-clear from the Centre, the BMC is complicating matters with its decision to only selectively test asymptomatic high-risk people (that is, close contacts of positive cases), as per a report in Yahoo News.
The BMC’s testing criteria differs from the ICMR guidelines that state that all asymptomatic high-risk contacts, such as family members, between fifth and 14th day of suspected exposure, should now be tested.
The Karnataka government’s COVID-19 task force on Thursday decided to purchase of additional two lakh rapid test kits to identify coronavirus infections in the state more rapidly. “Approvals have been given to a company mentioned in the official list of the Chinese government for the supply of kits and once it comes the number of tests will be increased further,” Deputy Chief Minister Ashwath Narayana was quoted as saying about the decisions taken at the task force meeting, in a release from his office.
PCR vs rapid tests
India has previously been going with the Polymerase Chain Reaction (PCR) method to test for coronavirus, which, as per the Indian Council of Medical Research, is foolproof and widely used. As per a report in Indian Express, this is done after taking nasal or throat swabs of the patient, from which RNA is extracted and converted to DNA, which is then amplified before being checked for confirmation of the virus. The test takes up to nine hours.
As per a report in Moneycontrol, serology tests or rapid test kits are blood tests that track down antibodies, which are created by the immune system for fighting off a disease. The test requires just two drops of blood from a pinprick to detect a virus and takes only 15 or 20 minutes to get a result. This test has three distinct advantages over traditional tests: they can be mass-produced and are relatively less expensive and easy to self administer.
Controversy over efficacy
As per the ICMR, while rapid tests can be a good tool to check for community transition, it is not a confirmatory test for SARS-CoV-2 that causes the coronavirus infection. Guidelines released by the ICMR on 28 March state that these rapid kits should only be used for preliminary screening.
“Positive test indicates exposure to SARS-CoV-2. Negative test does not rule out Covid-19 infection,” as per the guidelines. A subject, after taking the rapid test, must still take the PCR test to get confirmation that he is indeed negative for the virus.
Bought tests, burned fingers
While there are reasons to be optimistic, India needs to tread cautiously. Several countries that rushed to place orders for these rapid kits have resulted with burned fingers. As per a report in Bloomberg, the UK, after stocking up on more than 4 million finger-prick antibody blood tests available on Amazon and in pharmacies, is now looking for a refund.
Spain, after purchasing thousands of antigen tests from a Chinese supplier, discovered that the kits often fail to detect the disease. The Czech Republic also found tests it purchased from China to be less reliable than stated, while leaders in neighbouring Slovakia have been critical of the kits, as per the report.
“Until we have independently validated tests, governments shouldn’t be rushing in to buy millions of them,” Rosanna Peeling, director of the International Diagnostics Centre at the London School of Hygiene and Tropical Medicine, told Bloomberg.
Updated Date: Apr 17, 2020 11:30:00 IST