Containing the Transmission of COVID-19: A Modeling Study in 160 Countries

Abstract

Background: It is much valuable to evaluate the comparative effectiveness of the coronavirus disease 2019 (COVID-19) prevention and control in the non-pharmacological intervention phase of the pandemic across countries and identify useful experiences that could be generalized worldwide. Methods: In this study, we developed a susceptible-exposure-infectious-asymptomatic-removed (SEIAR) model to fit the daily reported COVID-19 cases in 160 countries. The time-varying reproduction number (R _t ) that was estimated through fitting the mathematical model was adopted to quantify the transmissibility. We defined a synthetic index (I _AC ) based on the value of R _t to reflect the national capability to control COVID-19. Results: The goodness-of-fit tests showed that the SEIAR model fitted the data of the 160 countries well. At the beginning of the epidemic, the values of R _t of countries in the European region were generally higher than those in other regions. Among the 160 countries included in the study, all European countries had the ability to control the COVID-19 epidemic. The Western Pacific Region did best in continuous control of the epidemic, with a total of 73.76% of countries that can continuously control the COVID-19 epidemic, while only 43.63% of the countries in the European Region continuously controlled the epidemic, followed by the Region of Americas with 52.53% of countries, the Southeast Asian Region with 48% of countries, the African Region with 46.81% of countries, and the Eastern Mediterranean Region with 40.48% of countries. Conclusion: Large variations in controlling the COVID-19 epidemic existed across countries. The world could benefit from the experience of some countries that demonstrated the highest containment capabilities.

Keywords: COVID-19; epidemic; mathematical model; the effective reproduction number; transmissibility.

Figure 1

Study design for analyzing the differences of capability to control COVID-19 among 160 countries.

Figure 2

Flowchart of the SEIAR model.

Figure 3

The reported cumulative number of cases of COVID-19 in 160 countries as of August 22, 2020. The map depicted in these figures were taken from Wikimedia Commons (http://commons.wikimedia.org/wiki/Main_Page).

Figure 4

The time-varying reproduction number (R_t), the coefficient of determination (R²), and p of model fitting results.

Figure 5

The spatial distribution of basic reproduction number (R₀) and the effective reproduction number (R_eff) of COVID-19 in different countries. The map depicted in these figures were taken from Wikimedia Commons (http://commons.wikimedia.org/wiki/Main_Page).

Figure 6

The spatial distribution of I_Tn and I_Cj in 160 countries. I_Tn is defined as the grade of time it will take to bring COVID-19 under control, and n represents the level of the time required to control the COVID-19 epidemic. I_Cj is the grade of countries where COVID-19 has been brought under control (R_eff <1) as of August, 22, 2020; j represents whether the country under study has the ability to control the COVID-19 epidemic. The map depicted in these figures were taken from Wikimedia Commons (http://commons.wikimedia.org/wiki/Main_Page).

Figure 7

The transmissibility and control effect classification flow chart to control COVID-19 in 160 countries. (A) shows the classification process of 160 countries; (B) shows the time each region needed to bring COVID-19 under control.

Figure 8

The ranking of I_AC among160 countries.

Figure 9

Estimated R_t value based on different p in six selected countries in six WHO region.