Why are Asian countries outperforming the Western world in controlling COVID-19 pandemic?

ABSTRACT

COVID-19 already caused more than 1,260,000 deaths around the world. However, mortality rates are not equal amongst the different countries. Mortality rates are ranging from less than 1 death per million in Taiwan, Vietnam and Thailand to 1,112 deaths per million in Belgium. In the present article, we report a striking difference in mean per million mortality between Asian and European countries (2.7 vs 197 deaths per million population, p < 0.001). In addition, we confirmed that the later a specific country was hit by the epidemic, the milder the impact on mortality during the first 50 days was. We analyzed several factors that may have contributed to this discrepancy including population age, previous experience of epidemics in the modern era, social acceptance of physical distancing and face masks, percentage of active smokers and lastly genetic prothrombotic mutations.

Introduction

COVID-19 is the worst pandemic the world experienced since the 1918 Spanish flu. SARS-CoV-2 caused over 25 million infections worldwide, as of November 8^th, 2020, resulting in more than 1,260,000 deaths[1]. This pandemic deeply affected modern society and economics, since alternative ways of working, traveling and communicating had to be figured out.

The virus rapidly spread from the Eastern world to Europe and America. Despite the adoption of similar containment measures, mortality rates largely differ among countries: no Asian country is appearing in the top 20 in terms of mortality per million inhabitants. China, for instance, only reports a mortality rate of 3 per 1 million population and around 86,000 confirmed cases overall[2]. The aim of the present paper was to further assess this phenomenon, possibly understanding the reasons why Asia outperformed the rest of the world in managing COVID-19.

Methods

In the present study, COVID-19 deaths per million population at 50 days after the beginning of the epidemic were compared between the Europe/America and the Central and Southeast Asia groups. The beginning of epidemic was defined as the day each country reported 0.1 deaths per million[3].

Data were extracted from Worldometers.info[1] and OurWorldInData.org[3] and stored in a Microsoft Excel (Microsoft Office 2019, Microsoft Corporation, Redmond, WA, US) which was also used for data analysis.

For both groups, the top 10 countries in terms of population, highest number of documented COVID-19 cases and highest number of COVID-19 deaths up to July 18th, 2020, according to the United Nations statistics department[4], were included. Countries that did not reach the criterion for the beginning of epidemic at the time of the analysis were excluded.

Data were analyzed through two different scatter plots for each group, and two lines for the best fit were identified and presented as Pearson’s R² coefficient.

Results

A total of 24 countries, 10 from Central and Southeast Asia and 14 from Europe, North America and South America fulfilled the inclusion criteria and were encompassed in the present analysis.

Mortality ranged between 647 deaths per million population in Belgium, where the epidemic started on March 11^th, and 0.1 deaths per million in Myanmar, where the epidemic began 5 weeks later. Mortality within the first 50 days of the epidemic significantly differed between Asian and European countries (2.7 vs 197 deaths per million population, p < 0.001). Figure 1 shows an R² of 0.47 for Central or Southeast Asia countries and a relatively constant mortality rate over the first 50 days of epidemic in each country. The scattered plot reveals R² of 0.57 for the Europe/America group, showing a decline in the mortality per million population during the first 50 days of epidemics amongst the countries that were hit by SARS-CoV-2 later during the year.

Figure 1.

Scatter plot of COVID-19 mortality per million population at 50 days after the beginning of the epidemic. Panel A: European/American countries. Panel B: Asian countries

Note: Y-axis ‘Death rate’ scale in Panel A ranges between 0 and 650, while in Panel B it ranges between 0 and 50.

Discussion

In the present study, we report a substantial difference in COVID-19 mortality rates between the Western and the Eastern worlds. In accordance with our previous report[5], we also confirmed that the later a specific country was hit by the epidemic, in Europe and in America, the milder the impact on mortality during the first 50 days was. This observation leads us to several other considerations. In spite of the fact that the epidemic started in China, to which trade and travel bond most Asiatic countries, Asian countries have been grossly outperforming the Western ones in terms of survival. Many factors may have contributed to this difference while others could favor better outcomes in Europe and America but not necessarily in Asia.

Attributing the difference to underreporting this far into the pandemic is not realistic, as most countries have tested a similar percentage of their population (between 10% and 25%)[6]. Similarly, it is improbable that lockdown strategies were implicated in these differences, as they were enforced throughout the world with similar time frames and modalities. Moreover, according to Google Mobility Trends data, the disruptions to normal life were even less severe in Asia than they were in Europe and in America[7]. On the other hand, analyzing the differences in population characteristics, recent history and social behavior may explain this trend.

Firstly, the Asian population is younger in comparison to the European and North American ones. Median population age in Asia is 31 years old, as compared to 42 years old in Europe and 35 in North America. In Italy, notably hit by COVID-19 early and severely, the median population age is 45.5 years old, one of the highest in the world[8]. As elderly are more susceptible to infectious diseases and their sequelae, differences in mean population age may partially explain the mortality rates.

Secondly, the SARS outbreak of 2003 may have given some Asian countries (notably China, Hong Kong and Taiwan) a few advantages in fighting COVID-19. In fact, Asians already knew how to face an epidemic, and took early actions as soon as the first cases were reported, enforcing travel limitations, lockdowns and deploying modern technology to track and trace the infection[9]. On the contrary, Europe and the US did not have any direct experience with epidemics in the twentieth century and did not raise their level of attention with regards to COVID-19 until it was too late. When restrictions were finally enforced, the population was less willing to collaborate, as the critical importance of these limitations was not understood.

Thirdly, in Europe and in America, the adoption of the facemasks and of the physical distancing was not an easy task for the authorities to enforce. In the Asian culture, the maintenance of interpersonal distance and the use of facemasks are more common, pandemic or not. These measures were hardly understood and adopted by Western populations at first. Facemasks, hand sanitizers and physical distancing are crucial to reducing COVID-19 morbidity and mortality rates.

Fourthly, the high prevalence of active smokers amongst the male population in Asia might have played a role in reducing COVID-19 cases[10]. In fact, a counterintuitive negative correlation between active smoking and a progression to a more severe COVID-19 clinical picture has been previously reported [11,12]. Although the mechanisms behind this phenomenon have yet to be fully understood, it is not implausible that active smoking may have contributed to reducing SARS-CoV-2 mortality in Asia.

Furthermore, prothrombotic genetic patterns are less common in Asia than in the rest of the world[13]. Individuals carrying prothrombotic mutations might be more prone to developing COVID-19-related microvascular lung vessels obstructive thromboinflammatory syndrome (MicroCLOTS) [14–16].

Finally, since the reduction in mortality has been related to the consumption of certain foods, the increased presence of different products in Eastern cuisine may have a protective effect on COVID-19 diseases[17].

While other factors (Supplemental Table 1) may also have contributed to successfully fight the pandemic on the Eastern battleground, the Asian population played a crucial role in taking the lead. Just as Marco Polo did 700 years ago, traveling to the Eastern world – understanding the customs and traditions of a different culture – may help us improve our own strategy in order to get ahead of COVID-19.

Funding Statement

This work was supported by the Departmental funds only.

Disclosure statement

No potential conflict of interest was reported by the author(s).