Epidemiology-based analysis of the risks and elimination strategies of the monkeypox outbreak in 2022

Abstract

Human monkeypox, caused by monkeypox virus, has spread unprecedentedly to more than 100 countries since May 2022. Here we summarized the epidemiology of monkeypox through a literature review and elucidated the risks and elimination strategies of this outbreak mainly based on the summarized epidemiology. We demonstrated that monkeypox virus became more contagious and less virulent in 2022, which could result from the fact that the virus entered a special transmission network favoring close contacts (i.e., sexual behaviors of men who have sex with men outside Africa) and the possibility that the virus accumulated a few adaptive mutations. We gave the reasons to investigate whether cattle, goats, sheep, and pigs are susceptible to monkeypox virus and whether infection with monkeypox virus could be latent in some primates. We listed six potential scenarios for the future of the outbreak (e.g., the outbreak could lead to endemicity outside Africa with increased transmissibility or virulence). We also listed multiple factors aiding or impeding the elimination of the outbreak. We showed that the control measures strengthened worldwide after the World Health Organization declared the outbreak a public health emergency of international concern (PHEIC) could eliminate the outbreak in 2022. We clarified eight strategies, i.e., publicity and education, case isolation, vaccine stockpiling, risk-based vaccination or ring vaccination, importation quarantine, international collaboration, and laboratory management, for the elimination of the outbreak.

Keywords: elimination; epidemiology; monkeypox; outbreak; prediction; risk.

Figure 1

Distribution of the cumulative confirmed human MPX cases in 2022 as of November 7, 2022 as per the data from the CDC (1).

Figure 2

Phylogenetic relationships of some monkeypox viruses (MPXVs) during the years 1958–2022 (A) and in recent years (B). Those MPXVs in 2022 shown in green letters were classified into two lineages (2022A and 2022B), which were similar to the two MPXVs detected in the USA in 2021 shown in red letters.

Figure 3

Transmission routes of MPX in animals and humans.

Figure 4

Counts of global weekly new confirmed human MPX cases in the 2022 outbreak as per the data from the WHO (29).