The COVID-19 pandemic in rich and poor countries

Abstract

Large differences in the number of registered SARS-CoV-2 cases per capita in different countries encourage research into the causes of this phenomenon. In particular, a strong linear correlation was revealed between the gross domestic product per capita (GDP) and the numbers of cases per capita (CC) registered in African countries as of February 1, 2022. A non-linear correlation and datasets for African and European countries corresponding to August 1, 2022 show that CC values increase for richer countries probably be due to higher levels of testing. The much lower values of registered accumulated numbers of cases and deaths per capita (DC) in Africa are most clearly explained by the low testing level than by the influence of other factors. In some countries, the number of undetected COVID-19 cases may be tens or even hundreds of times higher than the number of registered ones, which increases the probability of the appearance of new dangerous SARS-CoV-2 strains and reduces the prospects for a quick end to the pandemic. Many unreported cases make it difficult to analyze the impact of vaccinations and other factors. In particular, the decline of DC values and the case fatality risk (DC/CC) with increasing vaccination rates in Europe requires additional research.

Endemic characteristics of SARS-CoV-2 infection

“…To estimate the endemic global number of new daily cases we can use the average DV value for 2022 (around 1 million), presented in Table 1. More optimistic prediction 300, 000 DV  follows from the minimum of DV i values illustrated by the blue solid line and non-linear correlation approach [33], which yields the best fitting curve 8 0.9684 1.2484 10 ( 674.5) DC t    (7) for the 2022 dataset (shown by the dotted blue line). Thus, the global daily numbers of SARS-CoV-2 cases can vary from 300 thousand to one million and the daily numbers of deaths from 1.0 to 3.3 thousand (if we use the CFR value from the Table 1 corresponding to 2022).…”

“…To estimate the global visibility coefficient let us take the number of cases per million 72,524 registered worldwide as of August 1, 2022 [8]. On the same day, the average value was 460,834 for European countries with high enough testing level (more than 3 tests per capita) [33]. It means that the real numbers of cases can be approximately 6 times higher than registered figures.…”

Can we start to ignore the SARS-CoV-2 disease?

“…Probably, this fact is connected with a low testing level. It was shown in [13] that insufficient testing does not allow detecting a lot of COVID-19 cases and deaths in poor countries (e.g., in Africa). Similar trend is visible in other countries and worldwide.…”

Estimations of SARS-CoV-2 endemic characteristics

“…It is necessary to emphasize that the presented estimates refer to the laboratory confirmed cases only. Due to the high numbers of asymptomatic patients and insufficient testing level, the real number of SARS-CoV-2 cases is much higher [33][34][35]. To estimate the global visibility coefficient let us take the number of cases per million 72,524 registered worldwide as of August 1, 2022 [8].…”

“…To estimate the endemic global number of new daily cases we can use the average DV value for 2022 (around 1 million), presented in Table 1. More optimistic prediction DV ≈ 300, 000 follows from the minimum of DV i values illustrated by the blue solid line and non-linear correlation approach [33], which yields the best fitting curve for the 2022 dataset (shown by the dotted blue line). Thus, the global daily numbers of SARS-CoV-2 cases can vary from 300 thousand to one million and the daily numbers of deaths from 1.0 to 3.3 thousand (if we use the CFR value from the Table 1 corresponding to 2022).…”