Active COVID-19 cases mount; Mumbai shows signs of flattening curve 

COVID-19 cases are rising consistently across India, but Mumbai, often held up as the bellwether for assessing the state of the pandemic,  is offering a glimmer of hope.

On Monday, June 20, India reported a total 12,781 COVID-19 cases; the number of active cases increased by 4,226 and reached 76, 700.

Active cases are those that are yet to complete a 14 day-cycle and are currently in the "infectious” stage. Because a large number of people are also declared "recovered" from the disease daily, active cases are calculated by subtracting the number of recovered patients from the new ones. ​

Of the new cases, 4,004 were recorded in Maharashtra, followed by 3,376 in Kerala and 1,530 in Delhi.

Mumbai, which was the first city to start reporting a rise in infections during the current surge, is showing a decline in the test positivity rate (TPR).

The city, which was reporting a TPR of over 15 percent early last week, registered a TPR of 13 percent on June 19.

Daily infections in the city, too, have been in the range of 2000-2,300 over the last few days, and are not rising despite an increase in testing.

Vijayanand, a Tamil Nadu-based data analyst who has been tracking COVID-19 cases since the beginning of the pandemic, said Kerala and Delhi—the two states that have also closely mirrored the Mumbai graph—are expected to show a similar pattern soon.

“However, for these two states and some others like Karnataka and Tamil Nadu, the pattern needs to be studied closely for at least a week to 10 days,” he said.

Overall, 28 states and Union territories in India showed a rise in active cases on Monday and the daily TPR crossed 4 percent, the highest in 130 days. On a positive note, the rolling average of the weekly TPR is much lower at 2.45 percent.

Uptick losing momentum

Many experts said the surge in COVID-19 cases may have already lost momentum.

“There is a definitive decline in the growth of daily active cases for the past more than a week. The rise in weekly test positivity rate also seems to have slowed down to around 2.5 percent,” said health economist Rijo M John.

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As of June 20, the growth rate in active cases was about 6.5 percent at the national level.

“It appears to me that this uptick has already lost momentum at the national level and it wouldn't be surprising to see the daily reported cases going down in the coming days,” John said.

Vijayanand, too, pointed out that though the hospitalization rate in Mumbai had inched up to 2.5 percent, only about 0.5 percent of the oxygen beds in city hospitals were occupied.

“This trend gives hope for the rest of India. There is definitely a rise in cases, but like South Africa, where there was a wave recently caused by Omicron sub-variants BA.4 and BA.5, there may be very few serious cases needing medical care in hospitals,” he said.

Immunity levels

Maharashtra-based infectious disease expert Dr Ishwar Gilada said COVID-19 infections seem to have slowed over the past few days in the states reporting the sharpest rise in cases. The trend still needs to be tracked over the next few days, he said.

Nationally, he said while the rise in cases was likely to due to newer Omicron strains, there is no indication of a large wave yet.

Dr. Gilada also said the number of weekly deaths too had risen slightly—for example, 79 deaths were registered over the last weeks, compared to the 45 fatalities reported in the previous week, but they were mostly in the high-age groups or of people with multiple comorbidities.

“While genomic surveillance remains a crucial exercise, we also need to carry out a national-level sero-survey to assess whether the immunity against SARS CoV 2, acquired either through natural infection or vaccination is waning,” he said.

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This, he said, would give the country an important tool to devise strategy for containing future outbreaks.