Oral manifestation of the monkeypox virus: a systematic review and meta-analysis

Background: Mpox (formerly known as monkeypox) is a global public health concern, given the recent outbreaks in non-endemic countries where little scientific evidence exists on the disease epidemiology. Oral lesions among mpox cases have been poorly reported. Our aim was to estimate the overall prevalence of oral manifestations among patients with mpox globally.

Methods: In this systematic review and meta-analysis, an extensive literature search in PubMed, Scopus, Web of Science, Embase, Cochrane, and preprint servers (medRxiv, arXiv, bioRxiv, BioRN, ChiRxiv, ChiRN, and SSRN) and assessment of all published articles, conducted across the world, until Nov 15 2022 as per the PROSPERO registration protocol (CRD42022371249), was undertaken. Primary studies (case series, cross-sectional, retrospective, prospective designs) that reported the oral/oropharyngeal symptoms among laboratory-confirmed mpox cases were included. The characteristics of the study, information on the number of cases, and symptomatic status were extracted from the included studies. The quality of the included studies was assessed for bias. Random-effects meta-regression with DerSimonian & Laird estimator, and subgroup analyses were conducted using STATA (v17.0). The degree of funnel plot asymmetry was assessed using Egger's test when at least 10 estimates were available. The heterogeneity between studies was assessed using the I² statistic. The primary outcome was the pooled prevalence of oral manifestations in the examined population.

Findings: 19 studies were included with 4042 laboratory-confirmed patients with mpox for qualitative and quantitative synthesis. The pooled prevalence of oral manifestations in the investigated population was 36.75% (95% confidence interval [CI]: 23.77-50.65). Heterogeneity was found to be high in the current meta-analysis (I² = 98.24%; p < 0.001). Subgroup analysis revealed a pooled prevalence of 39.96% (95% CI: 21.42-59.91) of sore throat, 24.80% (95% CI: 8.14-46.32) of mouth sore, 18.24% (95% CI: 0.34-52.54) of tonsillitis and 17.99% (95% CI: 15.66-20.43) of mouth rash from the included studies.

Interpretation: Oral manifestations are common in patients with mpox, with variations in prevalence across the sites within the oral cavity, and geography of the studies. Healthcare workers should be wary of the oral signs and symptoms of mpox in endemic and high-risk areas.

Funding: None.