Mumbai: COVID-19 doubling rate drops to 947 days

The doubling rate of COVID-19 infections across Mumbai has once again dropped below the 1000-mark after 45 days. As per the data, until August 20, the city's doubling days was 947 days until August 20. The previous lowest doubling rate was on July 7, at 949 days. Officials have attributed this to the rise in daily COVID-19 cases and have also warned citizens to follow Covid-appropriate behaviour as the next two weeks are very crucial and cases are likely to surge due to the festive season.

The doubling rate is the time taken for the total number of cases to double. The rate depends on the reproduction number (RO) and the serial interval of a disease. Senior health experts have blamed citizens for this impasse. “People have begun venturing out and taking the situation casually. Some are not wearing masks and those who do are not wearing them properly. Social distancing has now gone for a toss,” said a health professional.

Senior doctors from the civic-run hospitals said that the numbers suggest a clear trend, but all are mild cases and people need to be vigilant and cautious. “We had an Omicron outbreak in Mumbai and still it is dominant. Now there are sub-lineages due to which whole genome sequencing is a must. Moreover, the ward-wise break-up of rising Covid cases shows that areas in the western suburbs are observing a faster spike,” said a doctor.

“We need to be on vigil. We need to ramp up our genome sequencing. The positivity rate in the last two to three months was 1-3 per cent and now it has crossed 10 per cent in Mumbai,” he added. The main reason doctors are not worried about the fourth wave right now is that the Covid variant in circulation is still Omicron.

“Waning immunity post prior infections and vaccination, increased social interactions/overcrowding, increasing travel and reduced precautions (masking, sanitising) have all possibly contributed to the surge that we are presently experiencing. Fortunately, it does appear that despite increasing numbers, the proportion of those infected who have the severe disease is low, and we are likely to experience a surge similar to what we witnessed in January,” the doctor concluded.

Officials believe that the new Omicron variant – BA.2.75 – is the driving force behind the recent surge in Covid cases. “The latest genome sequencing of samples has shown that BA.2.75 is dominating other variants in the state. Thankfully, however, it is not causing any severe infection as the death rate is low,” Dr Pradeep Awate, state surveillance officer, said.

Dr Umang Agarwal, an infectious diseases consultant at PD Hinduja Hospital and Medical Research Centre, said, “The Covid cases have certainly gone up with over 800 cases reported yesterday in Mumbai. Lack of masking and social distancing may be the most important contributing factor. Moreover, our booster vaccination rates remain low which may be an important contributing cause.” According to Dr Agarwal, the doubling time might have gone down but it was temporary and a better picture of the situation will emerge over the next few weeks.

Published on: Sunday, August 21, 2022, 10:34 PM IST