Why are COVID-19 deaths lowest in poor, densely populated South Asia?

Vaccines, temperature and demography could all be reasons

HEALTH-CORONAVIRUS/INDIA-SLUM A doctor wearing a hazmat suit and a mask, conducts a swab test on a man, to check if he has the coronavirus, during a nationwide lockdown in India to slow the spread of COVID-19, in Dharavi, one of Asia's largest slums, during the coronavirus disease outbreak, in Mumbai, India | Reuters

Throughout the month of April, Amitabh Kant, the CEO of NITI Aayog, tweeted data related to India’s fight against COVID-19, comparing and contrasting figures with the rest of the world. “Pandemics such as COVID require tough and timely decisions from governments. India’s timely decisions have improved the doubling rate from three days to 12.53 days! If we had not acted on time, we would have had over 10 lakh positive cases today. Almost 44 times higher than our current no of cases,” he tweeted. According to NITI Aayog data, if a lockdown was not implemented, India would have witnessed over 10,22,283 cases.

“In the 12th week since the reporting of the first case in each country, cases in USA were 39 times higher than India, France cases were 7 times higher than India, Germany 9 times higher and Italy 11 times. India has consistently been an outlier,” he tweeted. “Italy reported the first positive case a day after India. On March 13, when India reported first death, Italy already had over 1000 deaths. In week 10, our death toll was 166. In same week, Italy was 110 times more. Now, Italy is 45 times more. India’s fatalities have been consistently low.”

Among those with confirmed coronavirus infections, India has a very low death rate. As of April 10, India had a 3.1 per cent death rate, compared to the US at 3.4 per cent; Spain has death rate of 9.73 per cent, and Italy has a death rate of 12.72 per cent. The UK has reported a death rate of over 12 per cent. The global average is estimated at 5.98 per cent.

How do the data add up?

As of April 19, India had 521 deaths, Germany had 4,543, France had 19,323, UK had 15,464, Spain had 20,463, US had 39,015 and the world faced 1,61,725 casualties. Going by that data, India accounts for 0.3 per cent of the global fatalities. And, this is not a trend limited to India. The low coronavirus infection and death rates have been an anomaly in South Asia, consisting India, Nepal, Bangladesh, Afghanistan, Pakistan, Sri Lanka and the Maldives, one of the most densely populated and poorest regions in the world.

South Asia hosts around 23 per cent of world population, with a density of 303 per square kilometre. To compare with the rest of the world: If India has 453 people per sq km (Bangladesh has 3 times more), the US has 36 people per sq km, Spain has 96 people per sq km and Italy has 206 people per sq km.

Infection tally and death count, as of April 26 in South Asia:

Pakistan: 12,273 cases, 269 deaths

Bangladesh: 4,998 cases, 140 deaths

Sri Lanka: 452 cases, 7 deaths

Nepal: 49 cases, 0 deaths

Maldives: 177 cases, 0 deaths

Afghanistan: 1,463 cases, 47 deaths

India: 24,942 cases, 779 deaths

Globally: 2.89 million cases, 202k deaths

That is, South Asia, with more than 20 per cent of the world population, accounts for a staggeringly low 1.3 per cent of the coronavirus cases and 0.6 per cent of the global fatalities.

What could be the reasons?

Low testing is obviously a clear indicator. According to latest data, if countries like the US, Spain and Italy conducted tests in the range of 15,000, 19,000 and 28,000 per million of the population, India, Pakistan, Bangladesh and Afghanistan conducted 420, 654, 262 and 191 tests per million.

However, as Kant pointed out in one of his tweets, India’s tests, conducted on the symptomatic people, revealed the lowest positives on total tested, at 4.4 per cent. This means that as a percentage of the total number of tests conducted, India had the lowest number of positive cases. Similar is the count across South Asia.

According to a report by the Lowly Institute, who took a note of the trend, a multitude of reasons ranging from vaccination to climate and demography could be behind it. “Some speculate tropical countries will fare better than temperate countries, potentially reflecting factors such climate, exposure to malaria, or even high tuberculosis vaccination rates. But, demography also favours South Asia. India, Pakistan and Bangladesh are among the youngest countries in the world, with 5–8 per cent of their populations aged over 60 and 2–3 per cent aged over 70. This compares with Italy’s age distribution of about 16 per cent aged over 60, and 10 per cent aged over 70. With around 85–90 per cent of Covid-19 deaths in the over 60 demographic this may make for a smaller population at risk.”

Demography aside, many reports have credited the widespread use of tuberculosis vaccine Bacillus Calmette-Guerin (BCG) in playing a role in inhibiting the spread of COVID-19.

A study published by the National Center for Biotechnology Information, United States hypothesised that countries who continue BCG immunisation programs would contain the spread of this new coronavirus better than those that did not have or have ceased their national BCG vaccination programs. “Certain live attenuated vaccines like the Bacillus Calmette–Guerin (BCG), an attenuated strain of Mycobacterium bovis, provide protection not only to a specific pathogen, but also against unrelated pathogens, some of which cause acute respiratory tract infections. Results showed that COVID-19 associated deaths relative to the size of the population were statistically significantly lower in countries with a national BCG vaccination programme than those that did not have or have ceased their national BCG vaccination programs (P<0.0058). The most affected country with the highest death toll was Italy, which historically never had a national BCG vaccination policy for all.”

Then, temperature could be a factor. In the tropical regions of South Asia, the virus might not thrive as much courtesy the climate, according to studies. Sunlight, heat and humidity can create conditions that are less favourable for the spread of the coronavirus, a public health official of the Donald Trump Administration said on Thursday. The results of a just concluded scientific study conducted by the Science and Technology Directorate of the US Department of Homeland Security, announced during a White House news conference on coronavirus, could be good news for India in its fight against COVID-19. "Coronavirus dies at a much more rapid pace when exposed to sunlight and humidity. The virus dies the quickest in direct sunlight. Isopropyl alcohol will kill the virus in 30 seconds," Bill Bryan, the Under Secretary of Homeland Security for Science and Technology, told White House reporters in the presence of President Donald Trump.