India is the second country that is engulfed by the COVID-19 pandemic after the United States. With 113 K deaths, it has 7.43 million cases. On Friday, nearly 63K new cases of COVID-19 were reported in India amid a downturn in the number of new positive cases. The South Asian nation has ramped up testing to 1.1 million per day now from 1,000 a day in March. For a country with 1.35 billion people, testing is crucial as early detection helps to curb transmission. A quick and easy COVID-19 paper-strip test, much like a pregnancy test, is set to hit the market, and experts predict that it could be a game-changer for India.

India uses two kinds of tests at present. One is the RT-PCR (reverse transcription-polymerase chain reaction) test, which takes from four hours to a day to produce results and is considered the gold standard of testing. A PCR test can cost up to 4,500 rupees. The second is the rapid antigen test, which is cheaper and produces results within 30 minutes, costing no more than 750 rupees per test. However, given the high rate of false negatives, it is also seen to be unreliable. The rapid antigen tests administered is not known, which only fuels concerns that the country’s coronavirus case numbers are being under-reported. Serological surveys showed that many more were infected than it had been suggested by official estimates.

The test “Feluda”, was named after a famous Indian fictional detective and the test is based on CRISPR, a gene-editing technology. Researchers estimate that the kit, known as Feluda, would return results in less than an hour and cost 500 rupees (approximately $6.75; £5.25). A leading Indian conglomerate, Tata, will make Feluda, and it could be the world’s first Covid-19 paper-based test available on the market. “This test is simple, precise, reliable, scalable and frugal,” Professor K Vijay Raghavan, the Indian government principal scientific advisor said in a statement.
Researchers at the CSIR-Institute of Genomics and Integrative Biology (IGIB) in Delhi, where Feluda was developed, as well as private laboratories tested approximately 2,000 patients for samples, including those who had already tested positive for coronavirus. They found that the new test had 96 percent sensitivity and 98 percent specificity. The accuracy of a test is based on these two proportions, the Sensitivity and the Specificity. A highly sensitive test will detect almost everyone who has a particular disease whilst a test that has high-specificity will correctly rule out almost everyone who does not have a particular disease.

Dr Maiti says that only a PCR (polymerase chain reaction) machine is required for the test, which is commonly found in laboratories and colleges. “No (other) special equipment is required. That is the beauty of this test. You need a simple machine with low-trained manpower to perform the test. You do not need a laboratory technician. You can deploy this in low-resource areas such as Ladakh and other remote parts of the country.” An early estimate for the kit puts it at 500 rupees (S$9.30), but it will likely be priced higher when it reaches the market.
Feluda makes COVID -19 testing simple
• Using nasal and throat swab on a patient a sample is collected.
• The patient’s sample is processed via the polymerase chain reaction to amplify the genetic material.
• The Feluda mix is then prepared, using the CRISPR-Cas9 protein to detect the DNA sequence-specific to the Sars-Cov-2 virus, which causes COVID-19.
• A dipstick or paper strip indicator is then dipped into the Feluda mix. Two reddish bands indicate a positive COVID-19 patient and a single band means the patient is negative.

By Jumana Jabeer