In this ecological study, instances of COVID-19 were more prevalent in European and high-income countries whose characteristics include an overall higher expenditure on the healthcare system, more health resources, longer life expectancy, better sanitation services, and higher tourism expenditures. Factors that were linked to increased COVID-19 fatalities included lower numbers of nurses per 1000 members of the population, under-nourishment, lower access to basic sanitation services, and lack of hygiene, as well as higher numbers of total tourist departures.
While the initial outbreak occurred in China, as of March 2020 the epicenter moved to Italy and is expected to move to the USA [10]. As of March 21, 2020, the countries with the highest number of COVID-19 cases were China, Italy, Spain, Iran, Germany and United States of America (USA), (Supp. Figure 2). It is worth noting that the ranking of these countries fluctuates due to the nature of the measures that were adopted to stop the disease progression and the variation on strategies for testing and early case detection [11]. Overall, the countries with the greatest prevalence of COVID-19 have higher incomes and higher health expenditures. These countries have a higher number of nurses/midwives, physicians, and hospital beds per population ratios (Table 1, Fig. 1). According to the WHO, the year 2020 was designated as the International Year of the Nurse and Midwife [12]. Based on the study findings, the most influential indicators for decreasing the case fatality is the overall income level as well as the number of nurses/midwives per 1000 people (Table 2, Supp. Figure 2). Such findings demonstrate the importance of nursing staff, particularly in pandemic settings, to achieve optimal health outcomes.
Despite the fact that the economy and overall healthcare expenditures are key measures for logistics and operations, such systems can become crippled in a pandemic situation. This is due to exponential doubling of the number of cases within short time periods, as we saw in Italy when the healthcare system was flooded with a large number of COVID-19 cases [13]. Based on the Italian experience, many countries, imposed restrictions and activated social distancing orders to “flatten the curve” of the epidemic and buy time for their health systems to build capacity [14].
In terms of demographic differences, even though all age groups can be affected by COVD-19, the population characteristics of countries that have been heavily affected by COVID-19 showed an overall increase in the median age of the population, with the highest life expectancy at birth and at age 60 years. Countries with high numbers of COVID-19 cases had a life expectancy of 81.2 years compared to 64.1 years in countries with lower volumes of COVID-19 cases. In general, elderly people – particularly those with comorbidities – are at higher risk for severe disease and death [15]. With the exception of Italy, where the case fatality is holding at 7.2%, the sum of countries with a higher proportion of elderly people have no significant increased risk for higher case fatality. [16] Perhaps that is because the majority of patients who become infected fall into the middle age group. In addition, the majority of countries with longer life expectancies also have a more robust healthcare system, with resources that allow for better healthcare delivery.
The case fatality rate for COVID-19 is estimated to range from 2 to 3% [17]. The severity and case fatality vary according to the geographic location. [5] Possible explanations include variations in a host’s susceptibility to the virus. [18] In addition, selection bias – with over-reporting of severe cases – might have contributed to an over-estimation of fatality rates in different regions [19]. Other explanations include variations in the genomic structure of the virus due to continuous genetic mutation, resulting in less virulent strains affecting different geographic locations [20].
According to this study, during the initial stages of the pandemic period, countries with higher rates of under-nourishment, and less access to basic sanitation services had an increased case fatality. General measures for mortality, including mortality related to communicable and non-communicable diseases, as well as mortality related to household and Ambient air pollution did not have any significant association with fatality rates. On the other hand, countries with higher mortality rates, due to unsafe drinking water and a lack of hygiene, had higher COVID-19 case fatality rates. These findings suggest that poor countries are at a higher risk for increased fatality. While African countries are currently the least affected by the spread of COVID-19, worse outcomes would be expected there with the spread of the disease due to low incomes, poorer health practices and less resources allocated to health system.
More broadly, the tourism sector has contributed widely to the spread of COVID-19 [21]. From this study, the number of tourists (both arrivals and departures) – correlated with an increase in COVID-19 case numbers. Similarly, countries with higher numbers of departing tourists had a higher COVID-19 fatality rate. From this data, it is likely that current travel restrictions will help in limiting the spread of the virus to countries without prior exposure, particularly in Africa by lowering the number of tourists moving across countries.
This study has a number of limitations that must be considered. The measures of exposure are based on population averages, meaning prudence is required to apply grouped results at the individual level. The data used was based on nationwide vital statistics, wherein coding errors are known to occur. Importantly, the study was based on measurements of association at the univariate level, hence the association might be explained by other unmeasured confounders. On the setting of pandemic, events including new case diagnosis and mortality records are changing at exponential rates. Thus, as times goes, new data are expected to come with new results. Our goal from this paper was focused on analyzing the events during the initial phase of the Pandemic thus further studies will be needed to study the trend of these findings on later stages.
The study also has a number of strengths. It is the first to investigate the association between various demographic, health, and economic indicators with the spread and case fatality of COVID-19. A large multinational sample of all countries affected by the COVID-19 pandemic were included, with adequate representation from wide geographical areas. The large sample also allowed for sufficient statistical power to draw conclusions from null results. The data are publicly available, thus there is no concern over confidentiality or reproducibility.
In summary, COVID-19 is more prevalent in European and high-income countries. Along with ongoing measures for disease control and the widespread adoption of social distancing practices, measures to increase nursing staff, address under-nourishment, access basic sanitation services and good hygiene, together with strict regulations of the tourism industry to cope with pandemics are essential for disease control and decreased fatalities during the initial phase of pandemic. Poor countries, particularly in Africa, are at a higher risk for devastating outcomes and increased mortality. Economic support measurements for such countries are warranted.
