How Covid cases are spreading in India’s cities again

Nearly eight months have passed since India’s brutal second wave of infections peaked in the country

Nearly eight months have passed since India’s brutal second wave of infections peaked in the country. But the emergence of Omicron, a new and highly transmissible variant of Sars-CoV-2, has led to a massive rise in infections the world over, overpowering all other variants at a blistering pace. Though the variant appears far less virulent than Delta, its ability to evade vaccines and its higher transmissibility have sparked concerns that it could drag the fight against the pandemic back several months.

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In the past few days, a minor change in trajectory of new infections has been visible across several major cities in India. This, coupled with the fast-rising Omicron infections, has led some experts to speculate that this may become a steady stream of cases. But are cases rising everywhere, or is this spike limited to only a handful of regions? A look at four charts that try to answer this question.

After months of decline, cases are rising again

On December 20, India saw 5,161 new cases of Covid-19 reported across the country, making it the lowest daily case count seen in the country since May 18, 2020, or more than 580 days ago, according to HT’s Covid dashboard. But since then, a slow (but steady) bottoming out has started appearing. A week later, there were 6,139 cases across the country, and while this Tuesday, there were 9,155 new infections. The national daily case count touched 12,987 on Wednesday – the highest in a single day in nearly 50 days, data shows.

Pushed by these numbers, the seven-day average of new Covid-19 cases across India (a number which denotes a region’s case curve) has risen by more than 20% in just three days (from 6,641 on Sunday to 7,972 on Wednesday). This is something that has happened only once since the peak of India’s second wave – in early August, pushed by a mammoth rise in cases in Kerala, the national trajectory started rising for eight days.

[Chart 1: New Covid-19 cases across India]

Biggest spike, by far, visible in major cities

While the rise in infections at the national level (and even on state-levels) may appear minor, the bump in trajectories becomes far more apparent when India’s major metropolitan areas are narrowed down upon.

Delhi has seen its seven-day average of daily cases go up the most among the major cities – more than 1,000% from the start of December. At the start of the month, the Capital was reporting 31 cases a day on average. Since then, however, cases started rising slowly particularly through the second and third weeks of December. On Wednesday, for instance, the city saw 923 new cases, the most in a single day in nearly seven months, and the seven day average hit 370.

Mumbai has seen the second highest resurgence of cases. The city’s seven-day average has witnessed a rise of 552% from the start of this month – from 163 average daily infections to 1,063. In absolute numbers, the numbers from India’s financial capital are dwarfing every other city in the country. In the past week, 13% of all infections in India can be traced to just Mumbai alone.

These two cities are followed (at a fair distance) by Bengaluru, which has seen a 47% increase in average daily infections since the start of the month – from 166 daily cases on average for the week ended December 1, to 244 for the week ended Wednesday. In Chennai, average infections have gone from 135 a day to 184 a day so far in December (a rise of 36%). The case rate in Pune and Kolkata has grown by 15% and 8% respectively just this month.

To be sure, despite the rise, hospitalisation rates and reports of severe infections remain low across the cities mentioned above.

[Chart 2a to 2f: New Covid-19 cases in Delhi, Mumbai, Bengaluru, Chennai, Pune and Kolkata]

Urban centres are the main fuel in national tally

At the start of December, the six cities together were contributing to around one in every 10 cases reported across the country – of the 9,004 (on average) daily cases reported across India in the week ended December 1, only 975 could be traced to these six cities.

However, as the month has progressed, their share has nearly tripled to the national tally. In the past week, these six cities together have been responsible for three out of every 10 new Covid infections across India – of the 7,972 new infections of Covid-19 reported across India for the week ended Wednesday, these cities have reported 2,394.

[Chart 3: Share of six cities in the national Covid-19 tally]

Outbreak numbers also rising outside these cities, albeit slowly

While the six cities mentioned above remain the main cause of the rise in national numbers, it would not be fair assume that cases are rising only there. Even if their numbers are excluded from the national tally, the overall wave of India still shows a reversal in the past few days. While national numbers excluding these cities have dropped from the start of December (from a daily average of 8,029 cases to 5,578), the reversal in trajectory is there to see. For the week ended December 27, the seven-day average of daily infections in rest of India had dropped to 5,151, data shows.

[Chart 4: Seven-day average of new cases in six cities, and rest of India]

The rise in case rate in urban centres, however, is particularly worrying because if previous waves have been any indication, then a rapid rise in infections (as being witnessed in cities right now) cannot remain isolated for long. In both the first and second waves, cases were initially confined to metros, with cities such as Delhi, Mumbai and Chennai becoming the early areas of concentration of infections. The trend of a handful of high-population density hot spot regions emerging as first centres of infection, then a heavy and steady stream of cases from medium-population regions, has been identical in nearly every major country that has seen outbreaks.