Mumbai, Maharashtra’s ‘thick tail’ of cases a concern: Experts – Hindustan Times

As the second wave of Covid-19 abates in Mumbai and the rest of Maharashtra, the higher number of daily positive cases — a trend that medical experts term as ‘thick tail’ — has become a cause of concern.

“A thick tail essentially means that there is a continuing circulation of the virus in the area and there is susceptible population to which the virus can latch onto,” said Jacob John, professor at the Department of Community Health, Christian Medical College, Vellore. “Due to the relaxations in lockdown measures, this susceptible population may be mingling together leading to further infections,” said John.

While Delhi has gone down to report cases in two digits, Mumbai has been hovering between 400-600 and Maharashtra has been recording anywhere between 8,000-9,000 cases daily. The concern among experts is that the daily numbers, clubbed with relaxations in the stay-at-home orders may drive the third wave closer.

Dr Shashank Joshi, a member of the state’s Covid-19 task force, said, “It is hard to pinpoint the exact reasons causing the thick tail, but there are several factors that could be contributing to it.”

“The lack of adherence to protocols like sanitising, masking and overcrowding could be contributing factors. In addition, the population density, mobility, migration as well as lurking variants of the virus could be driving the thick tail,” said Dr Joshi.

The proportion of the population exposed to the virus and the proportion of the vaccinated population also plays a role in the thick tail. Some experts believe that places that did not implement significant measures when the pandemic raged could be experiencing a ‘thinner tail’ as their population is already exposed to the virus. States like Maharashtra and Kerala are experiencing a thicker tail as they may have controlled the transmission with better measures during the peak of the pandemic.

According to John, it appears that Mumbai was overall more efficient during the peak in terms of implementing lockdowns, testing, tracking, and managing patients. “Delhi, on the other hand, struggled. This could have exposed more people in Delhi to the virus, while Mumbai continues to have a susceptible population even now,” he said.

While Delhi’s positivity rate dropped down to 0.12% on July 1, Mumbai’s positivity rate stood at 1.7%. Delhi had carried out 76468 tests that day, while Mumbai had carried out only 38652 tests. “Mumbai’s testing has to go up. The more we test, the more cases will surface,” said Soumitra Ghosh, associate professor at the Centre for Health Policy, Planning and Management, Tata Institute of Social Sciences. “There should be more localised measures in terms of finding out where the cases are emerging from, the kind of population that is infected, etc. Such measures may provide more accurate answers to why Mumbai is experiencing a thick tail.”

The civic body has already started focussing on wards that are recording higher cases. The Maharashtra Covid-19 task force is also working out various strategies to ensure that the thick tail does not trigger a massive spurt. Among various measures that have been suggested include aggressive campaigns to promote Covid appropriate behaviour such as masking, handwashing, and maintaining a physical distance. Other measures include random testing of the population and tackling vaccine hesitancy.

“There is a pseudo sense of confidence among the population that has got vaccinated. We need targeted campaigns for such population so that they don’t drop the guard,” said task force member Joshi. “Vaccinating at a greater speed is also crucial to decrease the susceptible population,” he added.