Patients from outside, unlocking led to rise in Covid-19 in Delhi: Experts

Patients from outside Delhi seeking treatment there, reopening of the economy and low sensitivity of RAT might be the reasons behind the rise in Covid-19 cases, experts have said

Patients from outside Delhi seeking treatment here, reopening of the economy and low sensitivity of rapid antigen tests might be the reasons behind the rise in COVID-19 cases in the national capital, experts have said.

The positivity rate had declined to below six per cent by July end after hovering around 30 per cent in beginning of June. The cases too had started declining but in the last one week, there has been a spike in cases.

According to the Delhi government's health department bulletin issued on Monday, the positivity rate is 8.9 per cent. This has has left experts worried.

On Sunday, Delhi had recorded the highest single-day spike in cases in August at 1,450. Delhi has seen a fluctuation in the number of coronavirus cases since August 1.

On August 1, the city recorded 1,118 fresh cases while for the next three days, the number of infections reported in a single-day stayed below the 1,000-mark.

From August 5 to August 9, the number of fresh COVID-19 cases again stayed above the 1,000-mark only to come down to 707 on August 10.

Three days between August 11 and August 22 saw less than 1,000 fresh cases being reported -- August 13 (956), August 16 (652), and August 17 (787).

Co-incidentally, the number of tests conducted on the days the capital recorded cases below 1,000 were below the average 20,000 tests which are being conducted on a daily basis, according to data.

Dr BL Sherwal, medical director of the Rajiv Gandhi Super Speciality Hospital, said with people resuming work, the surge was expected.

"Almost everything is opening up... But if the cases cross 2,000, then it's a cause of worry. There is a slight surge but we will not say it's worrying as far as illnesses is mild or asymptomptaic. The mortality is in control and that is a big relief for all of us. Overall people are taking precautions," he added.

Dr Rajesh Chawla, senior consultant, respiratory and critical care medicine, Apollo Hospitals, said the surge is partially because of people coming from outside.

"In Apollo, 70 per cent of patients admitted are from outside Delhi. Patients come to Delhi for admission for better healthcare facilities. Their relatives are roaming around, some of whom are also positive cases," he added.

Experts also said the positivity rate dropped because of the rapid antigen tests, which are less sensitive. Delhi had commenced rapid antigen testing from June 18 and since then, the national capital's testing also rose to an average of 20,000 tests on a daily basis.

Ramanan Laxminarayan, the director of US-based Center for Dynamics, Economics and Policy said there has been no real flattening of curve in Delhi. The positivity rate dropped in between because the method of testing was changed. Rapid-antigen methodology is less sensitive - reported to be less than 50 per cent, so there is no real reduction in the number of cases.

"It is throwing up a lot of false negatives. False-negative are people who test negative through antigen test and think that they don't have a virus but actually they are positive and infected, he said.

"Not many are affected in Delhi. No doubt there will more cases in the days to come," he said.

Dr KK Agarwal, president of Heart Care Foundation of India, says Delhi has not yet reached its COVID-19 peak. The second serological survey revealed only 29 per cent of the people in Delhi have antibodies. Surges in the positivity rate will come and go till the time this number rises to 60 per cent. The national capital is going to witness another second peak.

"Also, a large number of people did not get themselves tested when the number of cases increased rapidly in June. They are undergoing tests now... since they have the anti-bodies, they are diagnosed positive during the rapid-antigen testing," he said.