The Capital on Tuesday again set a record for the highest Covid-19 cases reported in a single day with 6,725 new infections taking the total tally in the Capital past 400,000, as the outbreak continued to worsen to levels never witnessed before in the city.
Experts raised alarm over the continuously rising positivity rate – the proportion of tests that come back positive for Covid-19. The positivity rate on Tuesday stood at 11.29%, reinforcing the fact that the virus is spreading at an unprecedented rate amid festive season and rising pollution. A rising positivity rate typically suggests that a region is testing inadequately.
This means that more than a tenth (10.7%) of all tests in the past week have come back positive in the last week – the highest weekly positivity rate has touched in the city since July 7, when it was at 10.5%.
The rise in positivity rate took place even as the number of gold-standard RT-PCR tests on Tuesday witnessed a drop. According to Tuesday’s Delhi government bulletin, of the 59,540 samples tested in the past 24 hours, only 13,560 were RT-PCR – this is the lowest weekday RT-PCR sample size in the last three weeks.
Reverse transcription-polymerase chain reaction, or RT-PCR, tests are significantly better than rapid antigen tests at detecting positive cases – the latter has a higher tendency to give false negative. As a result, the higher the share of RT-PCR tests in overall testing, the more accurate the positivity rate is. In other words, the low RT-PCR count may be masking a much higher positivity rate on the ground.
In the past week, 5,536 new cases were reported on average every day, the highest this number has ever been in Delhi. Before this, the seven-day average (also known as the case trajectory) was highest at 4,174 at the height of the second wave on September 17 and 3,446 at the height of the first, which was on June 26.
Worried about the continuous spike in Delhi’s infections during the ongoing festive season, and at the start of winter, top officials from the Union and the Delhi governments met on Monday and discussed a recalibration of testing, treating and surveillance strategies.
This was the second time that the Centre intervened into rapidly rising Covid cases in Delhi. In July, Union home minister Amit Shah held a round of meetings with Delhi chief minister Arvind Kejriwal and other officials after which, testing, contact tracing and sero surveillance were ramped up in Delhi with the two governments working in coordination.
Last Tuesday, Delhi health minister Satyendar Jain claimed the positivity rate spike was down to testing the contacts of patients in a “targeted manner”.
Health experts, however, disagreed. Dr Lalit Kant, former head of the department of epidemiology and infectious diseases at the Indian Council of Medical Research, said, “The government says that the positivity rate is going up because more people are being tested. That is not true. For example, if you want to check the concentration of fat in a milk sample, it will be the same whether you test 100ml, 200ml or a litre. Of course, RT-PCR picks up more cases than the rapid antigen tests but the transmission in the city is going up.”
He added that the government needs to put in restrictions to reduce interaction of people — curbs on how many can gather for weddings and funerals, closing of non-essential services such as the cinemas, bars and restaurants, and limiting the number of people on public transport. The government should also stagger the timings of the markets and enforce mask-wearing through challans, he said.
“I don’t think we should attribute every rise and fall in the number of cases on testing; it does have a role, but a small one. That said, there is no rationale behind reducing testing because that will mean artificially reducing the numbers. And, we know RT PCR test picks up more cases than the rapid antigen test,” said Dr Shobha Broor, former head of the department of microbiology at AIIMS. “Look at what is happening outside, people are out and about. The markets are crowded, traffic is back to normal on the roads. The masks have become chin-accessories and no one is following social distancing. Add to that the increase in the levels of air pollution in the city and the dip in temperature,” Broor said.
With the rise in the number of cases, the number of hospitalisations has gone up to over 6,700 – the highest this has been since hospitalisations peaked at just over 7,000 during the September surge. There are over 15,700 beds earmarked for the treatment of Covid-19 in hospitals across the city, of which 43.6% are now occupied.
However, it is the occupancy in the intensive care unit (ICU) that has the government worried. As on Tuesday evening, almost 69% of the 3,175 ICU beds were occupied, according to data on the Delhi corona app. “1,000 ICU beds were added last month. But, given the surge in number, Delhi Government plans to scale up to 30,000 beds,” wrote Delhi health minister Satyendar Jain on Facebook.