Amid global speculation that Covid-19 may begin to tail off in the summer, India is witnessing its steepest jumps in cases over the past few days, even as mercury across the country is on the rise.
India has witnessed an increase of over 5 per cent every day in the total number of cases for the past nine days. In the past 24 hours alone, the country witnessed 6,977 new Covid-19 cases, taking the tally to 1,38,845.
The country's death count also breached the 4,000-mark. As of Monday, the death toll stood at 4,021 with 154 more people succumbing to the disease.
“It is hard to separate that (effect of rising temperature) from the effects of the lockdown. At any rate, the doubling time seems to be decreasing recently and this doesn't suggest that soaring temperatures will mitigate the spread of virus,” said Gautam Menon, professor of computational biology and theoretical physics at Ashoka University.
Menon also said India’s R-value -- which measures the number of persons each Covid-19 patient can infect -- is 1.2 to 1.3, with a considerable variation between states. “We calculated that it had been declining until about a week to ten days ago. But, it may be on the upswing now,” Menon said.
According to experts, the only transmission that could reduce due to higher temperature is the one through surfaces, as the lifespan of the virus on infected droplets gets reduced when mercury rises above 24 degrees Celsius. “When the primary transmission is through overcrowding and close contact, temperature will not play a big role,” said E Sreekumar, chief scientific officer, Rajiv Gandhi Centre for Biotechnology.
A Covid-19 study by John Hopkins and Michigan Universities had assessed if there was any correlation between country-wise average monthly temperature and total incidence of Covid-19 in India. “Our analysis, based on the current data, suggests we cannot rely on the hypothetical prevention (with inconclusive evidence) governed by meteorological factors and need public health actions, regardless of the seasonal weather,” the study said.
Jacob John, virologist and former ICMR chairman, said: “I will not count on temperature to slow down the epidemic. This is not an airborne infection. It passes through droplets and does not travel beyond three feet. Even by breathing, it can be passed on through the moisture in our breath.”
If an increase in temperature is not affecting the number of cases, will the drop in mercury have any impact? “The epidemic will end by winter. And then it will become a slow-spreading endemic infection. We will have to wait and see next year. whether it's going to be seasonal or throughout the year,” John added.