Covid-19: What you need to know today

My current obsession, in tracking the spread of the coronavirus disease pandemic around the world, is curves and waves — and readers of this column will likely encounter both this week, as well as some hypotheses about them.

Several experts including Dr Anthony Fauci, the US immunologist who is the head of the National Institute of Allergy and Infectious Diseases, believe that countries such as the US are not seeing a second wave of infections, just a continuation of the first. They are right — at the country level.

At the regional level, I have a different opinion. I believe that the first wave is over in at least some US states (New York is one, for sure), just as it is in continental Europe. As the infection has picked up in other US states, the plateauing and dip in the curve of daily new infections at an aggregate level — very evident in the middle of June — has been offset to an extent that it is no longer visible. But New York, for instance, is showing a curve that has flattened. It peaked in mid-April, and is now perfectly flat (the seven-day average for new cases, on July 11, according to the NYT, was 634, way off its peaks of nearly 10,000 in mid-April). If the state sees a consistent increase in cases — one hopes it doesn’t — it will definitely be a second wave of infections. The state has clearly fought off the first.

Also read: Coronavirus pandemic is going to get worse and worse and worse, says WHO chief

A similar curve, mapping daily new cases and the weekly average of new cases for the three Indian states that have seen the most cases — and which, on Sunday evening, accounted for 58% of all Covid-19 cases and 67% of all deaths in the country — throws up some interesting conclusions.

Delhi has definitely flattened the curve, although the peak is a little too narrow for my liking (in general, the peaks of many distributions, including infections, are more rounded and gradual).

Tamil Nadu appears to be in the very early stages of flattening the curve.

And Maharashtra is still seeing an increase in cases — although HT’s reporting has shown that Mumbai itself may have flattened the curve a bit.

Also read| 10 million children may never return to school after Covid-19 pandemic: Charity

At an aggregate level, starting the last week of June, the curve of infections (new cases) in these three states is beginning to plateau. Sure, this may be just an aberration — but if it is, we will know soon enough. The reason it finds mention here is because it is in keeping with the trend of how the infection has waxed and waned globally. For a little over two months, Delhi, Maharashtra and Tamil Nadu have driven India’s Covid-19 numbers. That may be changing.

Click here for complete coronavirus coverage

For the first time since early May, on July 10, the total number of new cases in the rest of the country exceeded the aggregate number of new cases in the three states. This, too, fits in with what we know of how the pandemic spreads through a population. Much like the US — this column has pointed out that the US can be compared to India because both countries are large in terms of geographical area (the US is much larger) and population (India has a much higher population) — India is beginning to see a significant proportion of the new cases coming from states outside Delhi, Maharashtra, and Tamil Nadu.

Purely in numerical terms, this could mean an increase in the number of new cases, perhaps to hitherto unseen levels. The good news from Delhi and, perhaps, Tamil Nadu, has to be tempered by the bad news from the rest of India.