Risk Factors of Human Mpox (Monkeypox) Infection: A Systematic Review and Meta-Analysis
Authors: Ugwu Chigozie Louisa J. , Bragazzi Nicola Luigi , Wu Jianhong , Kong Jude Dzevela , Asgary Ali , Orbinski James , Woldegerima Woldegebriel Assefa 
Published: August 2024

Background

Mpox (formerly Monkeypox) virus has affected the lives of thousands of individuals both in endemic and non-endemic countries. Before the May 2022 outbreak, Mpox infections were sporadically endemic in Central and Western Africa, still research into Mpox has been limited and lacking epidemiological data. Thus, identification of potential risk factors to better understand who is at risk of being infected is critical for future prevention and control.

Objective

To synthesize comprehensive evidence on risk factors associated with human Mpox transmission both in endemic and non-endemic countries from inception to March 31, 2024.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in conducting the systematic review. Electronic databases were searched. Two reviewers sifted the articles that were included in the review: firstly, by title and abstract, and secondly, by full text. We used the Newcastle-Ottawa Scale (NOS) to assess the risk of bias for included articles. Fixed or random effects meta-analysis were conducted when at least two studies reported odds ratios (OR), relative risks (RR), with 95% confidence intervals (CI). Heterogeneity was assessed using theI2statistic and sensitivity analysis was also done. The study protocol has been registered under PROSPERO with ID:CRD42023459895.

Results

947 articles were identified from the database search and 31 articles were eligible to be included in the systematic review. The findings of the meta-analysis showed that interaction with infected animals (OR= 5.61, 95%CI= 2.83, 11.13), HIV (OR= 4.46, 95%CI= 3.27, 6.08), other STIs (OR= 1.76, 95%CI= 1.42, 2.91), sexual contact/activities (OR = 1.53, 95% CI = 1.13, 4.82), contact with an infected person (OR = 2.39, 95%CI = 1.87, 3.05), being identified as men who have sex with men (MSM) (OR = 2.18, 95%CI = 1.88, 2.51), and having multiple sexual partners Mpox (OR = 1.61, 95%CI = 1.24, 2.09), were associated with an increased risk of contracting Mpox. However, patients who were vaccinated against smallpox had a lower risk of Mpox infection (OR = 0.24, 95%CI = 0.11, 0.55).

Conclusion

This study is the first meta-analysis on reported risk factors for Mpox. Our analysis demonstrated that certain factors were associated with increased risk of Mpox, whereas smallpox vaccination had a protective role against contracting Mpox. The study findings could facilitate future strategic public health planning and targeted intervention.

Key messages of this article

What is already known on this topic

Mpox (monkeypox) is a zoonotic infectious disease of notable global public health importance due to recent outbreaks in non-endemic countries.

Prior outbreaks of Mpox have been associated with travel to endemic areas in Western and Central Africa, contact with infected animals, and close contact with infectious lesions, particularly among household members.

What this study adds

This study is the first meta-analysis on reported risk factors for Mpox. Our study findings add to the body of evidence on Mpox research efforts and could assist in future Mpox global strategic intervention and control.

Our meta-analysis revealed a strong correlation between increased risk of Mpox infection, HVI, other STIs, physical and sexual contacts, and being identified as MSM.

While HIV infection may be a risk factor for Mpox, Mpox lesions could also facilitate the transmission of HIV and other STIs.

How this study might affect research, practice or policy

The results of this systematic review and meta-analysis provide evidence to support policymakers in future Mpox intervention and prevention in both endemic and non-endemic countries based on identified risk factors.