Mumbai: For the first time in 10 days, the city’s test positivity rate – the percentage of tests that come positive – jumped to 2% on Wednesday. While the positivity rate has been oscillating between 1.4% and 1.7% since June 28, civic officials attributed Wednesday’s marginal rise to focussed testing. The positivity rate, however, dropped down to 1.4% on Thursday. A positivity rate of 2% means the situation is still under control,” said additional municipal commissioner Suresh Kakani. “The marginal increase only suggests that our strategy of targetted and focussed testing is working. We are also gradually opening the city and there is plenty of movement of people, which could also be contributing to positive cases,” he said.

According to Kakani, the civic body has rolled out focussed testing for close contacts of positive patients, people living in containment areas, and inwards that are recording higher cases.

The positivity rate has to be correlated with the number of tests carried out in the city. Typically, when the number of tests goes down, the positivity rate shows a rise. Mumbai’s daily testing numbers have been fluctuating between 30,000 and 35,000. On Wednesday, when Mumbai carried out 31,944 tests, the city’s positivity rate jumped to 2% with 664 positive cases. On Thursday, the city carried out 37,802 tests and its positivity rate dropped to 1.4% with 540 cases.

Experts say the number of daily positive cases in Mumbai which run into hundreds suggests that there is a continuous circulation of the virus. This trend should push the civic body to increase the number of tests as the current tests are inadequate. For instance, according to BMC’s dashboard. Delhi is carrying out 11.53 lakh cumulative tests per million population and Bengaluru is carrying out 9.94 lakh tests per million. In comparison, Mumbai’s cumulative tests per million are at the lower end at 5.3 lakh, according to BMC’s dashboard. DrAjitPampatwar, a medical officer in K-West ward, said they are reaching out to residents in sealed buildings for testing. “We are also testing people in hotels, at construction sites, and other crowded areas like malls and grocery stores, etc. Overall, the positivity seems to be very low and a majority of those who are testing positive have a mild infection,” he said, adding the ward, which covers Andheri west, Vile Parle and Juhu, is now recording anywhere between 40 and 60 positive cases daily. During the peak in April and May, the daily positive cases ranged between 900 and 1,100 in the ward. According to Kakani, the civic body is set to roll out the fifth serological survey to better understand the exposure of the population to the virus. “This upcoming survey will have a sample size of around 4000 people randomly selected from all wards. It will help us gauge the situation before the third wave.” The fourth serological survey had covered only the pediatric population and revealed that nearly 50% of children had antibodies against the virus. The third survey, conducted with a sample size of 10,197, had revealed that nearly 36% of people had developed antibodies. The previous serosurveys showed more population living in slums was exposed to the virus as compared to the non-slum population.