Patients from outside, reopening of economy behind rise in COVID-19 cases in Delhi: Experts

COVID-19 patients from outside Delhi seeking treatment here, reopening of ecomy and low sensitivity of rapid antigen tests might be behind recent rise in instances of viral disease in city, experts have said.

positivity rate h declined to below six per cent by July end after hovering around 30 per cent at beginning of June. Cases too h started declining. But in last one week, re has been a spike in cases.

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

On Tuesday, Delhi recorded highest single-day spike in cases in August at 1,544, surpassing Sunday's figure of 1,450. Delhi has seen a fluctuation in number of coronavirus cases since August 1.

On August 1, city recorded 1,118 fresh cases and for next three days, number of single-day infections stayed below 1,000. From August 5 to August 9, number of fresh COVID-19 cases again stayed above 1,000-mark, only to come down to 707 on August 10.

Between August 11 and August 22, three days saw less than 1,000 fresh cases being reported. On August 13, city registered 956 new COVID-19 cases, August 16 h 652 fresh instances of viral disease, and August 17 reported 787 cases.

Co-incidentally, number of examinations for detection of COVID-19 conducted on days capital recorded cases less than 1,000 were below aver 20,000 tests being conducted daily, according to data.

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

"Almost everything is opening up... But if (daily) cases cross 2,000, n it's a cause of worry. re is a slight surge but we will t say it's worrying as far as illnesses are mild or asymptomatic. mortality is in control and that is a big relief for all of us. Overall people are taking precautions," he ded.

Dr Rajesh Chawla, senior consultant, respiratory and critical care medicine, Apollo Hospitals, said surge can be partially attributed to people coming from outside.

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

Experts also said positivity rate dropped because of rapid antigen tests, which are less sensitive. Delhi h commenced rapid antigen testing from June 18, and since n, national capital's testing rate also rose to an aver of 20,000 tests daily.

Ramanan Laxminarayan, director of US-based Center for Dynamics, Ecomics and Policy said re has been real flattening of curve in Delhi. positivity rate dropped in between because method of testing was changed.

rapid-antigen methodology is less sensitive -- reported to be less than 50 per cent, so re is real reduction in number of cases, he said.

"It is throwing up a lot of false negatives. False-negative are people who test negative through antigen test and think that y have t contracted virus. y are positive," Laxminarayan said.

"t many are affected in Delhi. doubt re will more cases in days to come," he said.

Dr (Col) Vijay Dutta, consultant, Internal Medicine for Respiratory Disease at Indian Spinal Injuries Centre, said ir institute never witnessed a decline in number of patients, which has remained constant.

He concurred with Laxminarayan and said rapid antigen tests can throw up a false negative in 50 per cent of cases, which means that if one is positive, it will t show m as positive.

"In most of time, rapid antigen test is being conducted. RT-PCR tests will detect positive patients," Dr Dutta ded.

Dr KK Agarwal, president of Heart Care Foundation of India, says Delhi has t yet reached its COVID-19 peak.

second serological survey revealed that only 29 per cent of people in Delhi have antibodies. A surge in positivity rate will come and go till time this number rises to 60 per cent. national capital is going to witness a second peak, he said.

"Also, a large number of people did t get mselves tested when number of cases increased rapidly in June. y are undergoing tests w... since y have antibodies, y are diagsed positive during rapid-antigen testing," Dr Agarwal said.

Im credits: PTI