Since India began to battle its third Covid-19 wave, Mumbai and Delhi have recorded the same number of cases. But even as the number of patients in Delhi requiring oxygen support is only one-third that of Mumbai, the Capital has reported a higher number of deaths.
Between December 15, when the coronavirus outbreak started to intensify again, and January 13, both Mumbai and Delhi recorded 2.04 lakh Covid-19 cases. However, Delhi reported 180 deaths in that period – 2.7 times the number in Mumbai, which recorded 66 deaths.
Experts believe the difference in these figures is a result of the varying comorbidities of the severely ill patients in each city, previous exposure to the coronavirus, different hospitalisation protocols and the procedure for reporting Covid fatalities.
Despite this, experts say it may be too early to draw any larger conclusions about the trajectory of the current wave from these figures because they are quite low.
“There is noise in the data,” said Dr Anurag Agrawal, director of CSIR-Institute of Genomics and Integrative Biology. “At this point, there is no reason to think the difference is significant.”
Experts note that the number of deaths escalate about 15 days after the number of cases begins to increase. Both Delhi and Mumbai have seen an exponential rise in cases over the past week so the effects will be visible only in a few days.
Expressed in terms of percentages, Delhi over the last month has recorded a 0.08% fatality rate – the proportion of the number of people who have died from the disease after being diagnosed with it. The figure in Mumbai is 0.03%.
The current death rate in both cities is much lower than the second wave in March 2021, when monthly fatality rate had crossed 3%. That wave was driven by the Delta variant of the coronavirus and struck when fewer Indians were fully vaccinated.
Delhi’s cold weather could also be influencing the fatality rate, said Dr SK Sarin, Vice Chancellor, Institute of Liver and Biliary Sciences and former chairman of Delhi Covid Task Force.
“During winters, respiratory problems in elderly population get aggravated,” he said. “The pollution and cold wave can add to the worsening of comorbidities. Also, if a senior citizen was not exposed to Delta, the natural immunity is lower against Omicron. But we don’t have data to examine all these hypotheses.”
Dr Avinash Supe, the head of the death audit committee for Maharashtra, said Mumbai follows a process of categorising deaths “due to other causes” if a person is infected with Covid but the virus was not the primary cause of death.
“We need to see the process adopted by Delhi, how liberal they are in categorising a death due to other reasons compared to Mumbai,” he said. Mumbai has said that 52 deaths since December 15 were “due to other reasons”. If these are added, Mumbai has recorded 118 deaths between December 15 till January 13, still lower than Delhi’s count of 180.
Both Delhi and Mumbai saw a surge in Covid-19 in mid-December. Mumbai recorded more than 20,000 cases on a single day for the first time on January 6, while Delhi breached that mark on January 8.
By January 8, the number of active daily cases in Mumbai touched a lakh but started declining within a week. As of January 15, it stood at 73,518. In Delhi, the figure stood at 93,407 on January 15 and has yet to breach the one-lakh mark.
Though both the cities have a similar active case pool, Mumbai has higher number of patients in hospital, and patients on ICU, oxygen and ventilator support.
Delhi has 2.5% of total active cases in hospital, less than half of Mumbai’s rate at 6.7%. Of those hospitalised in Delhi, 31.6% are on oxygen support and 25.9% are on intensive care support. In Mumbai, 43.7% of hospitalised cases are on oxygen support and 13.9% on intensive support.
In Mumbai, 8.3% of hospitalised patients are on ventilators. In Delhi, the percentage is 4%.
Despite a higher hospitalisation and ICU admission rate, Mumbai’s toll remains lower than Delhi.
Looking at the demographic details of 46 of the 180 people who have succumbed to Covid-19 in Delhi, 25 were senior citizens, while 14 were in the 41-60 years age group. In at least 37 cases, the patient reached hospital after their oxygen levels had dropped below 94, indicating a slight delay in seeking treatment. At least 34 of 46 deceased had some comorbidity that further contributed to the severity of the disease.
Twenty one of the people who died in Delhi tested positive for the virus after getting hospitalised for other ailments. Thirty five of the patients who died were not fully vaccinated.
In Mumbai, data available for 51 of the 66 deaths in January show that 44 of them had a comorbidity and 44 were aged above 60. The largest number of deaths continue to be among elderly people with a severe comorbidity, said Dr Rahul Pandit, an intensivist with Fortis hospital.
Four of the 51 were younger than 40, while three were aged between 40-60. Deaths among younger people are lower in Mumbai than in Delhi.
Most deaths in Delhi during this wave are due to ailments unrelated to Covid-19, said Sarin.
“Patients are incidentally testing positive for Covid after admission,” he said. “We are seeing very few deaths due to lung involvement”, a significant cause of death during the second wave.
Pandit of Fortis hospital said he hopes the peak of the third wave has passed in Mumbai. “We have to watch if the decline in cases continues for the next week,” he said. “But it seems that the city is already on a decline.” he said.
Iqbal Singh Chahal, Mumbai’s municipal commissioner, added that the city’s positivity rate is also on a steady decline. The positivity rate, which reflects the proportion of people who are positive of all tests conducted, rose from 0.5% on December 15 to 29.9% on January 6. It has started dropping since then and now stands at 19.5%.
“We have our fingers crossed,” Chahal said.
In comparison, Delhi’s positivity rate rose from 0.09% on December 15 to 30.6% on January 15.
This reporting was supported by a grant from the Thakur Family Foundation. Thakur Family Foundation has not exercised any editorial control over the contents of this article.