Breaching the Covid 19 Maginot Line?

About 90% of the global mortality was in the northerly latitudes, above roughly 30 degrees north

A comparative analysis of global Covid-19 data done in this paper in April indicated that although the pandemic was at various stages in different countries, and the public policy response was differentiated, a pattern was nevertheless discernible.

About 90 per cent of the global mortality was in the northerly latitudes, above roughly 30 degrees north. Mortality data was used for the analysis as a proxy for the spread of Covid-19, and not the infection data directly, because of the vast differences in testing across countries. We really do not know how many Covid cases are out there. Mortality data also suffers from reporting infirmities but is easier to compare across countries.

Two sets of countries were selected, each accounting for about a third of the global population. Practically all the advanced economies in North America and Europe fell in the northern zone. Since these countries have the best public health systems and state capacity, it appeared that the villain of the piece was the coronavirus itself that flourished in colder regions on the one hand, and that for some unknown reasons the effect of the virus was relatively benign in warmer climes on the other. India had one of the lowest mortalities per million amongst the bigger countries. Hypotheses such as sunshine that generated more Vitamin D in the tropics, the use of the BCG vaccine and anti-malarial drugs on account of tuberculosis and malarial fevers endemic in such areas etcetera, which provide better immunity against respiratory illnesses were advanced. It was argued that even seasonal flu had a higher mortality in the temperate zone compared to the tropics.

Six weeks later, while the overall distribution pattern of Covid deaths north and south of this imaginary Maginot Line has not substantively changed, some disquieting trends are in evidence that indicate that this Maginot Line is being breached.

The Northern countries share in global Covid mortality was 92 per cent on April 7, 89 per cent on April 20, and 75 per cent on June 6. The comparative figures for the Southern countries are 2, 3 and 15 per cent respectively. Southerners appear to be catching up after the initial lag through increased mortality rates.

Between April 7 and April 20, mortality per million increased by 115 per cent in the Northern countries and 326 per cent in the Southern. However, between April 20 and June 6, mortality per million increased by just 102 per cent in the northern countries, while it rose by 1,188 per cent in the southern ones.

 

The worst performers globally amongst the major countries during the last six weeks (April 20 to June 6), measured in terms of increase in deaths per million of the population, are Mexico (1,820 per cent), followed by the South Africa, Russia, Brazil, and India in that order. India (1,090 per cent) has performed worse than its neighbours, Pakistan (1,052 per cent) and Bangladesh (830 per cent), pointing to serious deficiencies in the management of the epidemic.

Epidemiologists and public health experts are better placed to give deeper insights and explain the reasons behind this lagged response and shifting trends than data analysts. One hypothesis nevertheless comes to mind. Recent research, especially that in the University of California, Santa Barbara, indicates that in cold and humid conditions droplets carrying Covid-19 can travel up to 20 feet, making the current physical distancing norm of six feet insufficient to contain its spread.

An explanation using the Occam’s razor rule of thumb suggests that the initial lower mortality per million in the South was because the chances of catching the infection were lower than in the North, especially under the same physical distancing norms. Community spread in the Southern countries was therefore slower, resulting in a lagged mortality impact compared to the Northern countries. However, following the lagged community response, the accelerated mortality trend relative to the North indicates that once contracted, Covid-19 may be as deadly south of the Maginot Line as north of it. The lessons from the Spanish Flu pandemic a century ago would suggest that although the common influenza virus may be more benign in tropical countries, coronaviruses might not be.

  

Despite the accelerating pace in the South, mortality measured in deaths per million of the population on average remains significantly lower (25) than in the Northern countries (110) that have a better public health infrastructure. Will the mortality figures be comparable by the time the pandemic runs its course?

There are however critical demographic, genetic and social differences between the two sets of countries that have a bearing on Covid mortality. First, the Southern countries are on the whole a lot younger, while Covid mortality has an old-age bias. Second, old people in the Southern countries live more at home, with their children. In the Northern countries, they tend to live more in old people’s homes or communities, a number of which have been devastated by Covid-19. It is therefore entirely possible that the normalised death count from Covid-19 might remain significantly lower in the Southern countries.

The author is RBI Chair Professor, ICRIER