Express News Service
CHENNAI: The latest data released on the doubling time of Covid-19 cases in the city, may be an indication that the rate of transmission has lowered significantly, especially in Royapuram and Tondiarpet zones. Tackling the contagion in these zones was a major challenge before the city corporation since the pandemic broke out.
As on July 7, the time taken for doubling of cases in Royapuram was 57.1 days, while the figures for Tondiarpet and Thiru Vi Ka Nagar zones were calculated at 32.7 days and 32.4 days respectively.
“These figures are welcome signs for Chennai as a doubling rate of above 14 days is usually recommended,” Chennai Corporation Joint Commissioner (Health) Madhusudhan Reddy told TNIE.
The doubling time is calculated using a seven-day moving average, taking into account the cumulative number of Covid-19 cases on the first day and seventh day. While a higher doubling time may be considered an indication of slow transmission of the infection, it is based on certain assumptions such as the testing, detection patterns, overall strategies and available resources are more or less the same across zones.
“In the case of Royapuram for instance, when we plot the doubling time on a graph, the trend seems to be going upwards,” ICMR National Institute of Epidemiology Assistant Director and Scientist Dr P Ganeshkumar said. “This shows that the public health measures such as increased testing, door to door surveillance, fever camps and lockdown have had a positive impact on the doubling rate,” he added. Chennai city as a whole reported 25.4 days doubling time.
While Teynampet, Madhavaram, Perungudi, Kodambakkam, Anna Nagar, Manali and Thiruvottiyur zones reported doubling figures higher than the city’s, Adyar, Ambattur, Sholinganallur, Valasaravakkam and Alandur zones have doubling figures lower than 25.4 days. “In some of these areas, the case load increased recently. So, stringent measures are being introduced and the situation there too will be brought under control,” the Joint Commissioner added.
Three main factors that the city corporation attributes to the higher doubling rate is the lockdown, testing and surveillance. “Apart from intensive identification and isolation of positive cases, we have doubled the number of tests and also set up fever clinics. The turn-out at a single fever clinic is 70-75 people on average in a two-hour period,” Reddy further said.
Source: https://www.newindianexpress.com/cities/chennai/2020/jul/09/chennai-on-the-road-to-recovery-2167354.html
