After clocking 37 per cent COVID-19 positivity ratio a month ago, the city has now brought it down to around 12 per cent following measures such as ramped up testing and increased surveillance, a top official of the Greater Chennai Corporation said on Saturday.
The government announcing a 12-day lockdown last month had also been largely beneficial as it reduced people's mobility, GCC Commissioner G Prakash said.
Ramped up testing for coronavirus, fever camps and door surveillance have brought down the positivity ratio to 10-12 per cent from about 35-37 per cent just a month ago, he told reporters here.
Since March, the civic body has conducted over five lakh RT-PCR tests.
"A month ago, we increased the testing as per Chief Minister K Palaniswami's instruction. This has been a major turning point (in bringing down the positivity ratio). As of today we have achieved a positivity ratio of 10-12 per cent, from about 35-37 per cent a month ago," he said.
"When 4,000 samples were tested in the past, there were 1,400-1,500 positive cases. And of the 13,000 samples being tested now, only 1,200 to 1,250 positive cases are being reported," Prakash added.
The Chief Minister's decision on enforcing the lockdown, which reduced the people's mobility, created a conducive atmosphere to increase the testing and step up the household surveillance, he said.
The metropolis had earlier reported heavy caseload of the virus, sharing a big chunk of daily numbers of the infections reported all over from the state.
The government had, among others, cited the population density, especially in many of the narrow lanes, as the key to the fast spread of the pandemic in this city.
Subsequently, an intense lockdown with more curbs was implemented in the city and suburban areas covered under three different districts--Chengalpet, Kancheepuram and Tiruvallore, from June 19-30.
The city has been of late witnessing a dip in the daily number of cases.
Tamil Nadu's cumulative tally of COVID-19 cases stood at 1,60,907 as of Friday, with Chennai's share being 83,377.
Prakash further said that about 11,53,399 people have attended over 18,645 fever clinics conducted in Chennai from May 8 to July 17.
Of those who attended, 60,686 symptomatic patients were identified and tested for COVID-19 and others were given medicines for minor ailments, he said.
On the civic body's recently launched Home Quarantine and Isolation Monitoring System (HQIMS), a smartphone application to monitor those quarantined, he said the method has been effective.
Nearly 8.5 lakh people were quarantined and several among them have completed the mandated isolation period.
"The Chief Minister allotting Rs 40 crore for this unique initiative had helped us to identify and deploy 4,500 youth for the monitoring work," Prakash added.