The method is easy, and so, it has an added advantage of not having the discomfort of sample collection using an invasive swab.
Coronavirus testing: Scientists have suggested an alternative testing method to detect COVID-19! Scientists have said that a low-cost saliva test that would allow people to collect their own samples, that too with minimal discomfort, could be a better way to detect the novel coronavirus, a report by news agency PTI stated. Currently, the test is conducted on samples that are taken using invasive throat or nasal swabs. The alternative testing method has not yet been introduced in India. However, giving their approval, scientists said that this method would allow faster and more accurate results, while the risk for healthcare workers who collect samples would be minimised.
The report stated that the COVID-19 diagnosis through the saliva testing method is better than the nasopharyngeal swab method, which is being used currently, since it allows people to collect their own samples. The method is easy, too, and so it has an added advantage of not having the discomfort of sample collection using an invasive swab. The saliva-based test only requires the people to spit into a sterile tube, after which they need to mail the tube to a laboratory for testing.
The report quoted Chennai-based L&T Microbiology Research Centre’s Senior Associate Professor AR Anand as saying that this technology is unique for conducting COVID-19 detection test since it does not require a separate step of extracting the RNA. The professor further stated that this was significant since the kits used for the extraction in the other tests were found to be prone to shortages.
He added that testing using this method was easier and it only needed a few reagents and a machine for RT-PCR.
The discussion around this method of testing gained momentum after the Yale School of Public Health was given an emergency use authorisation by the US’ Food and Drug Administration for Yale’s ‘Salivadirect’ diagnostic test for COVID-19. The report quoted an FDA statement as saying that this test did not require any special equipment, including swabs or collection devices, and only needed a sterile container.
While the test has not yet been approved in India, several scientists, including Anand, are pushing for further exploration of this technology. Anand said that a fast-tracked study should determine the differences between diagnostic tests done using the saliva RT-PCR tests and the nasopharyngeal RT-PCR tests.
A scientist of the Indian Council of Medical Research (ICMR), which is the nodal agency in the fight against coronavirus in the country, was quoted by the report as saying India was looking into various aspects of this method of testing, including the availability of kits. He added that currently no kit was approved in the country.
Apart from this, a study published in ICMR’s Indian Journal of Medical Research stated that samples of gargled water could also be a viable alternative to the swabs. They would also be easy and self-collectible, eliminating the need for trained healthcare professionals for the sample collection process.
The report also stated that the Director-General of ICMR, Balram Bhargava, told a parliamentary committee on Wednesday that the idea of using gargled water samples for collection and testing is already being considered.
At the moment, two types of tests for the detection of COVID-19 are available, and both use nasal and throat swabs for testing. One is the RT-PCR test which detects the genetic material of the virus using the polymerase chain reaction technique and this can take hours or even days to give out the result.
Meanwhile, the antigen COVID-19 test detects certain proteins in the virus and it can give out the results within a few minutes. The report added that the saliva test would be an improvement compared to both the techniques.