A Layman’s Guide To Projections And Prognosis Of Coronavirus Pandemic In India

With the onward march of Coronavirus to six different continents, trampling ruthlessly even the mighty nations and making a mockery of modern sciences, one often feels compelled to take a look at the projections and prognosis of the pandemic. However, the  technical papers, at times, are difficult to comprehend to a layman owing to the complex mathematical modelling entailed. Fortunately, a statistical analysis of empirical data of growth of Covid-19 infections in other countries, when interpolated with the containment measures taken therein, can help in a fairly accurate projection of spread of infection, particularly for a country like India, moving with a phase lag.

The statistical phases of growth of the pandemic within a country

Within a country, the spread of infection is seen to undergo five distinct statistical phases where different growth patterns are observed. These are; the first statistical phase (total infections less than 100), the second and virulent phase (total infections 100 to 1000). Here the number multiplies 10 times just in 7 to 10 days. The third stage is ushered when the country adopts stringent control measures and the per day growth starts receding from the second phase high of 25% and above to below 20%. This happens with a phase lag of nealy 10 to 12 days. The next phase, with even lower growth, is the typical “flattening of curve” phase. Finally, the fifth or healing phase is reached when number of daily infections fall below the number of recoveries. A glimpse of the statistical phases is captured  in the table below.

Attempting a projection of Covid-19 growth in India in April & May 2020

Based on the statistical dynamics in different phases, an attempted  projection would entail the following considerations.

Which stage of statistical cycle of infection the country is currently placed? For the first phase (0 to100 ), daily percentage growth is erratic and  growth predictions at this stage are  difficult and often off the mark.

For the second phase (100 to 1000), the country may experience a 25 % or more daily growth. The actual growth figures would to a large extent be depending upon the degree of containment measures and when they were adopted. India kept itself in this phase for nearly 14 days. (see table 1 and graph-1 below)

When the country has adopted a stringent containment measure (Stage 3)

Expect the percentage to drop after a week to 10 days of it. India went for a partial lockdown on 22^nd March (Sunday), with adoption of other social containment measures earlier. The daily percentage growth started seeing a dip around 26th to 28th March (from earlier high of 25% or more). But the major containment breach caused by the Nizamuddin Markaz event (in 2^nd-3^rd week of March), again caused a spurt and the growth soared to above 25% and  had a cascading effect for many days. (See graphs 1 & 2). The complete lockdown on 25^th March starts reflecting in the falling growth rate  from the 5^th of  April (growth falls to 18.5% from peak rate of 28 % on 2nd April ).  Beyond this day, the rate of growth gradually falls. (see graph 2)

Is lock-down continuing and no major containment breaches reported ? 

In such a scenario, the daily growth percentage would continue to fall, albeit gradually, receding to as low as 4% to 5% till even 8 to 10 days of completion of lockdown. Thus, one can presume the per day growth to be around 10 % even after 14th April and continue to gradually fall to 4% to 5% by the 24th of April.

Has the lock down been lifted if yes for how many days?

If the lock down is lifted, then after 10 to 11 days of it, an increase in daily growth percentage may be visible. As more intermingling of population takes place the growth may rise to 8 to 10 % within a week’s time.

Has the lockdown been continued and if yes then for how many days?

The continuation of lock down would gradually push the growth  further below to a low level of  4% to 5% and  to 1% or even 0 If lockdown continues for another three weeks.

Based on the above parameters, a projection is graphically depicted for two scenarios;

(a) where a lockdown is lifted for a week and then re-imposed for three  weeks again. 

(b) where a lock down continues till 15th of May.

Convenience and economic considerations wise, the first scenario would obviously be more desirable.

Based on the model, the graphs ( no. 3 ) depict that in case, even a week’s reprieve is  given,  with subsequent three weeks lock down, the total infections may zoom to a staggering figure of nearly 45,431 with around 23,357 active cases. However, if the lockdown/successful containment is to be continued for another month beyond 14^th of April, then the total infections would reach only 25,861 and the active  infection cases would plummet to only 3,787.

But what if the lockdown was removed after 14th April and gradual movement allowed for a week, with economic activities being fully opened there upon? Of course, immediate convenience and economic sustainability wise, this would be the most desirable option, but epidemiologically, it will be the worst case scenario, where infections would again flare up. (see graph 4)

As depicted in the graph, the number of  total infections are likely to sky-rocket to  over one lakh, with over 78,000 of active infections, if the the last course is adopted. This situation  may by then be well beyond the capacity of the health infrastructure to handle, (particularly in such a short span of time) or for the policy makers to douse, even with further stringent containments. Thus, adopting this course may not be prudent at all.

The prognosis

Although, the divergence in the projections and actual number of infections may widen, particularly more in the medium and long term, the broad contours of projections nevertheless are likely to hold.

In the event of a complete lifting of lockdown, the situation may spiral totally out of control. However, a continued and complete lockdown would have to be viewed from the economic and livelihood loss perspective as well. The extant supply chain and availability consideration of essential goods and services would be the key inputs to consider, particularly food, agricultural harvesting and medical supplies. With the buffer of essential goods depleting quickly, even the many not so essential goods and services would be needed  for their replenishment or as ancilliary supports.

The policy makers may altogether avoid both the extremes and adopt a more strategic approach. This may well be of continuing a compete lockdown till last week of April and extend the lockdown further till second week of May, only  to hotspots districts, cities and localities. However, this itself needs to be strictly implemented and be watertight, lest we see the resurgence of the contagion.

Reopening of economic activity, sector/ region wise may well require a granular approach and micro outlook.  Of course, all will depend on the ground situation and no choice would be easy at all. But as ordinary citizens, we are all hopeful and sanguine to survive this world war. As it is said; when going gets tough, the tough get going.

(The author is an IRS officer. He has a degree in  mechanical engineering, law and masters degree in economics. He is also associated as an expert panelist on information security with APRG+ group, of Global Forum ,OECD. Views expressed are personal.)