Delhi scales up COVID tests, situation improving as positivity rate dips

Positivity rate, which was around 30% in the beginning of June, drops to 13%

Suspected COVID-19 patients wait to be examined by medics at a government hospital Suspected COVID-19 patients wait to be examined by medics at a government hospital in East Delhi | PTI

More than 1.3 lakh COVID-19 tests have been conducted in the national capital over the last seven days, and a silver lining has emerged from the scaling up of tests, with the positivity rate, which was around 30 per cent in the beginning of June, dropping to around 13 per cent. A major ramping up of testing has been undertaken in Delhi since the middle of June, and in the week from June 24 to June 30 a total of 1,30,104 tests were conducted at an average of around 19,000 tests a day.

Even as the number of samples tested has gone up from around 5,000 in the beginning of June to around 19,000-20,000 per day now, the number of positive cases has shown a declining trend over the last one week. As a result, the positivity rate of the viral infection, which is the number of cases testing positive hundred samples tested, has gone down. On June 24, the positivity rate was 19.87 per cent. On June 23, when Delhi witnessed the highest ever single day rise in the number of cases at 3,947, the positivity rate was 23.28 per cent. On June 30, the positivity rate dipped to 12.80 per cent.

The number of samples testing positive has been on a decline over the past one week. On June 24, 3,788 people had tested positive, while the total number of tests conducted was 19,059. On June 29, the number of positive samples stood at 2084, while on June 30, 2199 samples tested positive at about 19,000 tests per day. 

According to the Delhi government's health department, a major proportion of the tests have been carried out using the rapid antigen technology, cheaper and provides test results within 15 minutes compared to the RT-PCR testing that is considered the gold standard for COVID-19 test, but which takes several hour hours to provide the result.

On June 30, while 9,585 tests were conducted using RT-PCR, 7,594 tests were carried out using rapid antigen testing kits. On June 29, the numbers were 9,619 and 6,538 respectively for the samples tested using the two testing methods.

The Delhi government has ramped up testing using rapid antigen kits. Initially, 193 centres were put up to carry out rapid antigen tests, and they focused on people living in containment zones. Hospitals and laboratories have now been asked to scale up the number of tests by using the rapid antigen testing method. More rapid antigen testing centres are being set up at the district level.

However, according to a health department official, while the rapid antigen tests are reliable when it comes to samples that test positive using the method, for people who test negative, a re-test is required through the more rigorous RT-PCR testing method.

Close to a lakh people have been tested since June 18 using rapid antigen tests. With around 8,000 people testing positive, the positivity rate in the rapid antigen tests is 7.46 per cent.