Dynamics of Mpox epidemics by the interplay of COVID-19 pandemic in Africa.

BACKGROUND

Mpox epidemics continue to spread to African borders following the outbreak that has affected over 120 countries and thus posed a threat to global health security. Dynamics of Mpox spread over time, fatality, and country-level risk were investigated intra- and post-COVID-19 pandemic to inform optimal surveillance, response, and prevention strategy.

METHODS

An epidemiological (retrospective cohort) analysis of complete weekly Mpox situation report across 20 African countries was conducted intra (January 2022-May 2023) and post (June 2023-September 2024) pandemic. Mpox epidemics and mortality were assessed against endemic-related exposures, and Mpox fatality rate, distribution, and patterns were assessed via summary analysis, spatial spread, and epi-curve respectively. Mantel Haenszel statistics assessed the confounding effects of COVID-19 and seasonality, while zero-inflated negative binomial model was fitted to evaluate the epidemic and mortality risk. Analysis was performed in Excel, QGIS, and Stata at 5% level of significance.

RESULTS

About 9446 confirmed Mpox cases occurred in Africa between January 2022 and September 2024, with DR-Congo accounting for over 75%. Mpox case fatality rate is 0.58% and significantly different intra (1.16%) and post (0.46%) pandemic (p < 0.001). Though fatality is more prevalent in clade Ia and Ib (58.1%), with a higher risk than clade Ia only (IRR = 4.46, 95% = 1.12-17.69), the Mpox outbreak spread more rapidly through clade Ia and II to 20 countries post pandemic. Risk of Mpox incidence is about four times higher post-COVID-19 than intra-pandemic (IRR = 3.77, 95% CI = 2.83-5.00). The epi curve reveals a mixed epidemic, with common-source and propagated patterns intra- and post -pandemic. While COVID-19 does not confound the association between Mpox mortality and endemicity (M-H = 6.821, p = 0.009), the association was confounded by seasonal variation and thus, 35% of Mpox mortality could be prevented by eliminating high-endemic spread.

CONCLUSIONS

Weak surveillance capacity was evident as African countries appeared to have relaxed health security and outbreaks response strategies post-COVID-19 pandemic. Scale-up of vaccination uptake against the Mpox virus is required, particularly for clades Ia, Ib, and II, to prevent Mpox spread and mortality. A consistent multi-country surveillance will be critical to contain Mpox epidemics.