There are 300 Covid patients for every square kilometre in Bengaluru, which reported a record 17,342 cases and 149 deaths on Saturday.
With the active caseload in Karnataka breaching the two-lakh mark on Friday itself, according to an analysis of Covid-19 patient spatial density done by Jeevan Raksha, an initiative of Proxima, supported by Public Health Foundation of India (PHFI), in Bengaluru Urban, Covid-19 positive patient density is 300 per square kilometre.
“In a pandemic environment, positivity is bound to be high in a densely populated city. In this scenario, Bengaluru has nearly 50% of Covid cases of the state,” said Mysore Sanjeev, convenor, Project Jeevan Raksha.
Mysore said the land area of the city was taken as 2,196 sq km and the population as 1,06,40,064 (as per population considered for Aadhaar generation by the state government).
Dr C N Manjunath, the state nodal officer for Covid-19 testing, explained, “The Chinese city of Wuhan is the epicentre of the world of Covid-19 but it is eight times bigger than Bengaluru. The population of both the cities is more or less the same. Considering that Bengaluru is one-eighth the size of Wuhan, obviously, the cases will be more because of the huge density.
“When the positivity rate is 20%, it has to be because of the congestion in the city. New Zealand and Australia hardly have any cases,” Manjunath stated.
“Cases are linearly related to the number of people living per sq km. Indirect theoretical extrapolation also shows that had it been the same strain of coronavirus, the transmissibility wouldn’t have been this high, so there has to be a mutant variant in the city,” he said.
Nodal officer for genetic confirmation of SARS-CoV-2 in the state, virologist Dr V Ravi noted that such a theory was yet to be proven. “There are 20 mutants in the state and 34 lineages in the city. The only way higher infectiousness is proved is by extensive contact tracing where a particular patient with a certain strain is infecting more people with a higher reproductive number R0, compared to the parent strain.
The other way is to do cell culture studies where the virus is isolated, a particle is added to the cell and see if the output is more for the mutant virus compared to the parent,” he said.
To study the correlation between closed spaces and virus transmission, the RGUHS has tasked 12 medical colleges in the city to study 24 slums, two slums each.
Dr P S Ranganath, HOD, Community Medicine, Victoria Hospital, said, “We’re trying to study why despite sharing public toilets and lack of hygiene, there are not many cases in slum clusters. We are testing 720 slum dwellers for both antibodies and active infection. The only way to cut transmission in closed spaces is mass vaccination but we found that the slum dwellers do not want to miss a day’s wages and get in line for vaccination. The government has to help them get vaccinated.”