According to a BBC report, the accuracy of the test depends upon two proportions – a highly sensitive test will detect almost everyone positive for COVID-19 while a high-specificity test will rule out those who test negative.
In March 2020, when the coronavirus pandemic was still in its initial stages, a team of two scientists, Dr Souvik Maiti and Dr Debojyoti Chakraborty, at the Council of Scientific & Industrial Research’s Institute of Genomics and Integrative Biology (CSIR-IGIB) in New Delhi, came up with a simple 'paper-test' to determine if you have COVID-19 in a few minutes.
The test is named after writer and film-maker Satyajit Ray's famous fictional detective, 'Feluda’, and detect the virus within an hour.
The test uses an indigenously developed CRISPR technology to know the genomic sequence of the SARS-CoV-2 virus. It helps in achieving quicker results and is less expensive.
The Tata CRISPR test is the world’s first diagnostic test to deploy a specially adapted Cas9 protein to successfully detect the virus causing COVID-19, a statement by CSIR said.
According to the scientists, the Feluda kit would cost Rs 500 and will be made by a leading India conglomerate, Tata. It could be the world’s first paper-based coronavirus test available in the market.
Professor K Vijay Raghavan, principal scientific adviser to the Indian government told BBC, "This is a simple, precise, reliable, scalable and frugal test."
Researchers at the Delhi-based CSIR-Institute of Genomics and Integrative Biology (IGIB) found out that the new test had 96 per cent sensitivity and 98 per cent specificity after it tried out the test on samples from around 2,000 patients, including the already tested positive ones.
The accuracy of the test depends upon two proportions – a highly sensitive test will detect almost everyone positive for COVID-19 while a high-specificity test will rule out those who test negative.
India’s drug regulator has cleared the test for commercial use.
With more than six million confirmed COVID-19 cases, India is the second country with the highest coronavirus caseload. More than one lakh people in the country have died of the virus so far.
India has finally started testing a million samples a day in more than 1200 laboratories across the country, using either PCR swab tests or the speedy antigen test, which works by detecting virus fragments in a sample.
After a slow start, India is now testing a million samples a day in more than 1,200 laboratories across the country. It is using two tests.
Dr Anant Bhan, a researcher in global health and health policy told BBC that scaling up testing in India hasn't meant easy availability yet.
"There are still long wait times and unavailability of kits. And we are doing a lot of rapid antigen testing which have problems with false negatives," Dr Bhan said.
"The new test has the reliability of the PCR test, is quicker and can be done in smaller laboratories which don't have sophisticated machines," Dr Anurag Agarwal, director of IGIB added.
The sample collection for this new Feluda ‘paper-test- will be similar to the PCR test. It will also require a nasal swab inserted a few inches into the nose to detect the virus.
The new Feluda test uses CRISPR which means Clustered Regularly Interspaced Short Palindromic Repeats. In a simplified way, it means a gene-editing technology to detect the virus.
The researchers believe that gene-editing works similar to word processing.
Here’s how – It is exactly like using the cursor to correct a mistake by changing an incorrect letter and adding the correct one.
Gene-editing’s main purpose is to prevent infections and treat ailments like sickle cell disease.
Two blue lines indicate a positive result, while a single blue line means the test has returned negative.
According to Dr Stephen Kissler, a research fellow at Harvard Medical School, "Testing remains a limited resource and something that we need to do everything we can to improve its availability. So Feluda is an important step in that direction.”