The novel coronavirus variant responsible for causing the second wave of Covid-19 is not just highly infectious but also stealthy, doctors say.
Hospitals dealing with Covid-19 patients stated that even when a patient has typical symptoms of the disease, they test negative for the viral infection, sometimes twice or thrice even through RT-PCR- which is considered the gold standard for Covid testing.
"We have received many such patients in the past few days. They had fever, cough, shortness of breath and the CT scan of the lungs showed lighter-coloured or gray patches. It is referred to as patchy ground-glass opacity in medical terms. The condition is one of the defining characteristics of Covid-19," Dr Aashish Chaudhry, managing director of Aakash Healthcare told The Times of India.
In order to confirm the infections, some of the patients underwent bronchoalveolar lavage (BAL), a diagnostic method where a flexible scope is passed through the mouth or nose into the lungs with a measured amount of fluid introduced and then collected for examination, which confirmed the infection diagnosis, he added.
However, all patients who had tested negative through conventional Covid-19 testing methods but had the symptoms came positive in the lavage test, he further emphasised.
Explaining what could cause this, Dr. Pratibha Kale, associate professor of clinical microbiology at the Institute of Liver and Biliary Sciences told TOI that it is possible that in these patients the virus didn't colonise the nasal or throat cavity because of which swab samples were taken from these areas didn't yield a positive result. "The virus attached itself to the ACE receptors, a protein found on the surface of many cell types in the lungs and that's why when the fluid samples from the organ were analysed, it confirmed Covid-19 diagnosis," she said.
One of the major repercussions of this, such patients can continue to spread the infection if they are admitted in non-Covid areas, also, it can delay the treatment, Dr. Vivek Nangia, the chief of the pulmonology division at Max Healthcare, said. Nearly 15-20% of the Covid-19 patients suffered from this problem, he added.