Delhi may go past Covid peak in Aug if cases keep falling: Experts

Experts see a definite flattening of the curve, but warn against complacency

NEW DELHI: The coronavirus disease (Covid-19) pandemic will enter its post-peak period in Delhi in the first week of August if the Capital maintains a steady decline in cases — which have averaged at 2,494 a day over the past week compared to 3,446 daily cases the week before — according to public health experts.

The experts said that the reduction marks a definite flattening in the new Covid-19 cases curve, but does not yet classify as a “reversal” of a peak because an untapped cluster or lack of precautions by people could still lead to a spike that pushes the daily cases higher than they have been so far. If the same trajectory continues, and new cases fall to about 1,500 a day for at least a week before falling further, then it can be said that the peak has passed, they added.

Active Covid-19 cases, or the number of people currently infected in Delhi has averaged around 26,000 for the past three weeks despite testing going up three times from 6,130 tests on May 31, to 18,586 on June 30 -which indicates an encouraging levelling off.

Delhi’s current positivity rate is 15.9%, down from 37% on June 13, when one in three people being tested for Covid-19 were diagnosed with the infection, which has infected 94,695 and killed 2,923 since it was first reported in the Capital on March 2.

“There has been a flattening, no doubt, with Delhi recording less than half of the numbers projected by the state government three weeks ago. If containment measures stay at the same levels, we would see a reduction by the end of the month and we will be over the peak in beginning of August. We can say the peak is over only after new cases have more than halved over a sustained period, say, from 3,000 a day to 1,500 day for at least a week,” said Dr Randeep Guleria, professor of pulmonology and director of All India Institute of Medical Sciences (AIIMS).

Other public health experts and epidemiologists agreed that the number of cases will fall by July-end, and accounting for slipups in containment, Delhi may get over the peak in early August.

“With very energetic household surveillance and increased testing, case count will rise for a few weeks. If this is accompanied by effective contact tracing and isolation, the case count should start falling by late July or early August and daily death count a fortnight later,” said Dr K Srinath Reddy, president, Public Health Foundation of India.

Daily deaths on average declined marginally to 62 this week, from last week’s average of 66. Since corresponding reduction in deaths get reflected around two weeks days after a decline in infections, there is likely to be a fall in daily deaths in Deli in another week to 10 days, the experts said.

“A fall in daily deaths over 10 consecutive days is a more stable indicator of decline in new cases as it accounts for undiagnosed cases as well. Deaths should be assessed accurately, both in and out of hospital, through testing and symptom-based verbal autopsy,” said Dr Reddy. Verbal autopsy is a public health tool relies on extensive interviews of health workers and caregivers to identify the cause of undiagnosed death symptomatically at the community or population level.

“It’s difficult to predict peaks, whether it is in Delhi or Tamil Nadu, because a lot depends on human behaviour and the protective measures taken after opening up. Cases go up as restrictions lift, which makes it important to widen testing to detect and contain,” said Dr Manoj Murhekar, director, Indian Council of Medical Research-national Institute of Epidemiology, Chennai.

The average daily testing is at its peak in Delhi so far, with an average of 19,000 samples being tested a day over the past one week -- the highest per million population anywhere in India -compared to 16,000 a week ago, and 7,000 a week before that.

A post-peak period signifies that pandemic activity appears to be decreasing, but countries need to be prepared for additional waves, according to World Health Organisation (WHO). “Pandemics have been characterised by waves of activity spread over months... Pandemic waves can be separated by months and an immediate ‘at-ease’ signal may be premature. It is important to maintain surveillance and update pandemic preparedness and response plans accordingly,” according to a WHO document on pandemic phases .

Dr Guleria cited the United States, where authorities thought they had a hold on the pandemic when cases fell after the New York peak and opened up too soon, leading to a second wave of infection. “The same happened in Bangalore, where cases rose after falling because the state opened up and people became complacent,” he said.

Delhi chief minister Arvind Kejriwal also warned against complacency in a web briefing on Thursday. “Experts are commenting on social media that Delhi’s peak has come and gone. Don’t listen to them. Wear masks, maintain social distancing, wash hands regularly, don’t make a mistake,” he said. “We have managed to bring the situation under control after a concerted effort. There is a saying, hope for the best, prepare for worst. That’s what we have to do.”

Cases continue to rise in the rest of the country, however. India crossed 20,000 cases in a day for the third time on July 3, for a total tally of 649,425 at a doubling rate of 20.