Covid-19: Cases start to plateau in third national wave

The trajectory of India’s third wave of Covid-19 infections appears to have started receding, with new cases at the national level contracting over the past week – the first time a trend reversal has been witnessed since the start of the Omicron surge in late December.

Experts say that if these trends hold it would be a crucial development as the onslaught of the third wave has been marked by a significantly smaller proportion of hospitalisations and deaths compared to the country’s first and second waves – a pattern consistent with global waves caused by the Omicron variant of Sars-Cov-2.

A total of 233,779 new cases were reported on Friday, the lowest in 17 days, according to HT’s Covid-19 dashboard. In fact, barring a minor uptick on Tuesday, daily infections have almost dropped every single day since January 20, when there were nearly 350,000 daily infections – the highest single-day tally so far in the third wave.

The seven-day average of daily infections (a number that represents a region’s case curve) in India soared to 312,180 cases a day for the week ended Tuesday – the highest so far in this wave. This number has now dropped to 279,100 for the week ended Friday – a fall of around 10%. While this drop may be minor, it marks the first time that the seven-day average of cases has started contracting since the third wave started in the final week of December 2021.

And while daily fluctuations in daily case tallies is not uncommon, particularly on weekends and holidays such as Republic Day, other statistical elements like test positivity rate – the proportion of samples tested returning positive for Covid-19 – appear to support the argument for a plateau. National daily positivity rate, which was 20.9% on January 23, has remained below that mark in the days that followed – on Wednesday, this number was 18%, and it fell further to 15.8% on Thursday.

At the state level, the trend in contraction of daily cases becomes all the more apparent. Of India’s 36 states and Union territories, for the week ended Thursday, cases in the third wave appear to have hit a plateau, and have receded in varying degrees in 29 regions, data analysed by HT shows. A total of 16 states and UTs have witnessed their numbers drop by more than 20% from recent peaks.

The biggest fall (with respect to the third wave peak) has been visible in West Bengal. The seven-day average of new cases in the state touched 17,523 for the week ended January 15, but has already dropped 72% to 6,135 for the week ended Thursday.

In Delhi, where the infection curve touched a peak of 23,529 cases a day for the week ended January 15, cases have dropped 67% to touch 7,857 average infections a day for the week ended Thursday – the second highest recession in the country.

These were followed by Jharkhand and Bihar, where cases have dropped 62% and 61% from third wave peaks, data shows.

To be sure, even if the third wave appears to be waning in most regions, it is by no means true for all states. The surge appears to still rising through most of south India and the North-East, data shows. The case trajectory is currently at the highest point in the third wave (and still rising) in at least seven regions, data analysed by HT shows. These are Andhra Pradesh, Kerala, Madhya Pradesh, Mizoram, Nagaland, Tamil Nadu and Ladakh. Meanwhile, numbers in Telangana, Meghalaya, Manipur, Jammu and Kashmir, and Karnataka have only shown very minor recessions (under 3%).

The plateau in numbers appears to be consistent with the preliminary projections by scientists who created Sutra – a mathematical model developed at IIT Kanpur and IIT Hyderabad to predict a peak in Covid-19 cases – which predicted a national peak around the final week of January.

“According to number from our tracker (Sutra), we predicted a peak of around January 23, and we’re currently seeing a peak on January 25, so we do think the worst of this wave is over… especially in regions like Mumbai and Delhi,” said M Vidyasagar, SERB national chair, IIT- Hyderabad and member of the Sutra consortium. “An important point that we have to be mindful of is that when we started off our projections, we had to analyse the numbers from South Africa. We had to be more pessimistic with our estimates because our job was to help the government prepare for what may have been the worst that could happen. So there were some scenarios where we feared cases could be much higher, but so far we have either avoided those, or that a large proportion of mild or asymptomatic cases ended up going unreported.”

He said in either case, it is better to track changes in statistics such as hospitalisation or ICU admission, because they represent the true on-the-ground situation, and as such should be used by policy makers as the statistic that should decide curbs.

“We think there’s a possibility of raw case numbers being underreported in many regions because of the milder disease being apparent in this wave. Which is why I think that the real message to convey is that the overwhelming majority of cases are very mild, therefore, policy markers have to rethink their triggers from number of cases to hospitalisations or ICU admissions — which truly represent the severity of the pandemic,” said Vidyasagar.

He added that in both Mumbai and Delhi, almost 80% of hospital beds remained vacant even at the peak of the curve, and while many curbs applied in those regions made sense during previous waves when hospitalisations were soaring, they did not this time.

India’s second wave, in particular, was marked by a soaring rate of hospitalisations which led to a record surge in daily deaths through the country.

Another factor that appears to have played a role in keeping hospitalisation and deaths low in the country has been vaccinations, experts added. As per the latest data released by the Union health ministry, nearly 95% of all adults in the country have received at least one shot of the Covid-19 vaccine, with nearly 75% of India’s adult population has been fully vaccinated.