Global Covid-19 deaths this week crossed 900,000. The six-weekly timeline and geographical distribution as of September 5 in the accompanying table has data for three major regions that account for 73% of the world’s population and 90 % of all Covid deaths.
The table indicates that the trends visible in the data available till July 21 (bit.ly/2Fbnp0f) are further entrenched. The earlier data showed the pandemic receding unevenly across the board. The alignment of the Covid axis had shifted from north-south (above roughly 30o North) to east-west, with most of the mortality concentrated in the transatlantic (including the Mediterranean system) area, mostly Europe and West Asia, and increasingly the Americas. India stood out as one of the worst performers globally, and the worst in South Asia.
The demographic contours of the Covid-19 pandemic are becoming clearer as more data pours in. Beginning with China, the pandemic moved westwards towards the transatlantic region, even as it was halted in its tracks in the country of origin by the second half of April 2020. Mortality, equalised to deaths per million for cross country comparison, rose dramatically in Europe, but was contained equally dramatically within four and half months, by mid-July.
The data updated to September 5 shows that the pandemic continues its uneven retreat, with four notable exceptions. The Covid axis has continued its westward march and is currently centred on the Western Atlantic. North and South America, with just 12% of the global population, now account for 54% of Covid-related deaths. If the legacy deaths in Europe are included, 23 major countries in the Americas and Europe (the transatlantic region), which together constitute a quarter of the global population, account for 80% of deaths to date. Eight countries in Asia, with 47.7% of the global population, account for just 10.8% of Covid deaths.
The most spectacular success in rolling back the epidemic has been in Europe (apart from China) where the six weekly growth rate of deaths was brought down to single digits within 18 weeks of the outbreak, and to below 3% within six months, Russia excepted. That the pandemic was quickly controlled in Europe despite its initial virulence is unsurprising as it has a good, scientifically driven health infrastructure. The inability of the United States to control the spread of Covid-19 so far, with adjoining Canada and even Mexico faring better, also underscores the critical role of effective leadership that relies on evidence-based science and expertise.
This dramatic rollback has not been replicated elsewhere. Each succeeding six weeks has seen declining mortality rates, but the decline is much slower than in Europe. Amongst the major countries, Mexico, South America, Turkey, Iran and India—countries with a relatively poor health infrastructure and scientific temper, and authoritarian leadership— stand out for their failure in containing Covid-19.
What is worrisome is that while Asia (ex-West Asia) currently accounts for only about 10% of global Covid deaths, the growth over the last six weeks is over twice that of the West Atlantic. This is largely on account of India. Could the Covid axis be continuing its westward march from the West Atlantic towards the Pacific and the Indian Ocean?
Over the last six weeks, four major countries, namely the US, Argentina, Japan and Australia, have shown an increase in the growth of Covid deaths over the preceding six week period. While the Japanese and Australian percentages are on a very low base, that the US should be part of this group is a little shocking.
India’s Covid mortality per million is currently under half the global average, a fourth of the East Atlantic, and one-tenth of the West Atlantic. However, it has the third-highest number of aggregate Covid deaths, after the US and Brazil. Also, India’s mortality growth over the last six weeks is exceeded only by Argentina, Bolivia, South Africa and Australia in the selected subset of 31 major countries. Like the US, India has performed worse than its neighbours despite its relatively better health infrastructure. Indeed, its Covid mortality per million (49.7) has further worsened with respect to Bangladesh (26.6) and Pakistan (28.7) over the past six weeks. It now stands at about twice the Asian average.
A model-based projection by the Washington DC-based Institute for Health Metrics and Evaluation (IHME) makes the apocalyptic prediction that Covid deaths in India could exceed well over half a million by January 2021. This projection is in line with a continuing westward march of the Covid axis. Back of the envelope calculations based on past growth trends, however, show that Covid deaths in India should not exceed 200,000, or 150 per million, by end January 2021.
Mortality growth has declined successively over six-week intervals, as elsewhere, and this trend can perhaps be expected to continue.
The geographical distribution and spread of Covid-19 is descriptive rather than explanatory. How do the various theories that have been doing the rounds since the beginning of the pandemic hold up in the light of incoming data? Medical experts and epidemiologist are of course best qualified to draw conclusions, and even they are struggling to unravel the capricious aetiology of Covid-19.
It does appear, first, the cold-warm climate theory that was rife in the early days of the epidemic has fallen by the wayside.
Two, the high initial mortality in Europe and the Americas could be because this was their first exposure to a coronavirus like SARS or MERS. Exposure to Ebola could explain the very low mortality in Africa to date.
Three, older people have been found to be most vulnerable to the acute symptoms of Covid-19. The surprisingly high mortality in Europe can also be ascribed to flawed management of the pandemic in old peoples’ homes in an ageing society.
Four, the theory that countries, where tuberculosis and malaria are endemic, may be naturally protected owing to widespread use of BCG and hydroxychloroquine continues to remain on the table.
Five, the genetic explanation also remains on the table as this appears to fit the data. The Asian gene pool is very different from the western, where Covid mortality is much higher. There are also differences between the West Asian, South Asian and East Asian gene pools. The mortality rates per million are very different in all these regions. Outside South Africa, mortality in Africa, with its distinctive gene pool, is very low despite its very poor health infrastructure. This is, however, also a little puzzling because Covid mortality in the US is higher amongst African Americans.
The author is RBI Chair Professor, ICRIER