Why Are People Testing Negative When They Have Covid Symptoms? Know All About The Desi Variant 'B.1.617'

"The Indian B.1.617 variant also carries the signatures for being more infectious, although those tests have not been done so far. It is plausible that this increased infectious potential of mutant viruses is a strong reason for the surge," said Dr. Shahid Jameel.

Representational Image (PTI)

New Delhi: Experts warned that there cases in which people while showing symptoms of the disease test negative in the RT-PCR test which is currently the more reliable test for Covid-19 available. Only after multiple test only did they test positive. 

These experts advise that those who show the symptoms must be treated as quickly as possible before the condition worses while waiting for test results.

Prevent, don't wait for test results

Dr Neeraj Gupta, professor in the Department of Pulmonary, Critical Care and Sleep Medicine at the Safdarjung Hospital in Delhi told PTI that experts have a general perception that guiding factor for treatment should be of the clinical symptomatology and the CT scan reports rather than relying only on the RT-PCR test which has a sensitivity of only 70 per cent. 

A rapid antigen test has a sensitivity of only 40% whereas, the antibody tests has a sensitivity of 90% but they are only useful for confirming past exposure for SARS-CoV2 hence aren't very useful during the early stages of testing.

Dr. Gupta further explained "All the treatment strategies should be guided towards preventing the progress of the disease from its mild to moderate or moderate to severe and for that we cannot wait on test reports. We have to go by clinical symptoms".

While speaking to ABP News, ICMR Dr. Samiran Panda said that cases of negative tests are rare but they do exist. He said that people should continue to follow Covid protocols and if they notice symptoms they should immediately speak to a doctor for advice on the next step. 

 

'Desi' Variant - B.1.617 

National Centre for Disease Control (NCDC) reported that a "new double mutant variant" of the novel coronavirus was found in India, whether it is the reason for the sudden spike in cases is yet to be determined. Classified as 'B.1.617', this variant has been found in eight nations so far ever since it was first deteced in October 2020.

The B.1.617 variant contains mutations from two separate virus variants - E484Q and L452R. The double mutant strain was found in samples collected from various part of the country.

Virologist Shahid Jameel, director of the Trivedi School of Biosciences at Ashoka University told IANS, "we don't yet know whether further mutations would make current vaccines useless, this is unlikely. However, the efficacy of vaccines may be reduced due to mutations."

Will the vaccine still remain effect? 

According to Dr. Jameel, "We don't yet know whether further mutations would make current vaccines useless. This is unlikely. However, the efficacy of vaccines may be reduced due to mutations. This was observed in Phase 3 trials of the Johnson & Johnson and the Novavax vaccines. These were effective against the original virus and the UK variant, but showed reduced efficacy against the South African and Brazil variants. India's Covaxin also seems to neutralise the UK variant well in laboratory tests, but results are not yet available from the population or for the B.1.617 variant."