Risk factors associated with human Mpox infection: a systematic review and meta-analysis

Abstract

Background: Mpox emerged as a significant global public health concern during the 2022-2023 outbreak, impacting populations in both endemic and non-endemic countries. This study reviews and synthesises evidence on the risk factors associated with human Mpox transmission across these regions.

Methods: A systematic search of peer-reviewed original studies was conducted across Scopus, Embase, Web of Science and PubMed databases, covering publications up to 31 March 2024. The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Two authors independently screened the articles by title, abstract and full text. The Newcastle-Ottawa Scale used to assess the risk of bias for included articles. Fixed- or random-effects meta-analysis was conducted when at least two studies reported ORs or relative risks, with 95% CIs. Heterogeneity was assessed using the [Formula: see text] statistic. This study was registered on PROSPERO (ID: CRD42023459895).

Results: The systematic review identified 947 articles through database searches, of which 31 met our inclusion criteria. The meta-analysis revealed significant risk factors associated with Mpox infection. Interaction with infected animals (OR=5.61, 95% CI 2.83, 11.13), HIV infection (OR=4.46, 95% CI 3.27, 6.08), other sexually transmitted infections (OR=1.76, 95% CI 1.42, 2.19), unprotected sexual activities (OR=1.53, 95% CI 1.13, 2.07), contact with an infected person (OR=2.39, 95% CI 1.87, 3.05), identification as men who have sex with men (OR=2.18, 95% CI 1.88, 2.51) and having multiple sexual partners (OR=1.61, 95% CI 1.24, 2.09) were associated with increased Mpox infection risk. Conversely, smallpox vaccination was associated with a significantly reduced risk of Mpox infection (OR=0.24, 95% CI 0.11, 0.55).

Conclusion: Identification of risk factors associated with Mpox provides insights for strategic public health planning, enabling targeted interventions for high-risk groups and optimising resource allocation to strengthen Mpox control efforts.

Keywords: Epidemiology; Global Health; Other infection, disease, disorder, or injury; Public Health; Systematic review.

Figure 1. Flowchart illustrating the study selection process.

Figure 2. Forest plot illustrating the associations between Mpox infection and various factors: (A) animal interaction, (B1) HIV status before (B2) and after sensitivity analysis, (C) STIs and (D) comorbidities. STIs, sexually transmitted infections.

Figure 3. Forest plot illustrating the associations between Mpox infection and various factors: (A1) MSM, (A2) sexual activities, (B1) multiple sexual partners before and (B2) after sensitivity analysis, (C1) close contact with a positive case before and (C2) after sensitivity analysis, (D) age, (E) smallpox vaccination and (F) education. MSM, men who have sex with men.