Clinical Features, Antiviral Treatment, and Patient Outcomes: A Systematic Review and Comparative Analysis of the Previous and the 2022 Mpox Outbreaks

Abstract

Background: This study aims to comparatively analyze clinical features, treatment, and patient outcomes between the previous and the 2022 mpox (monkeypox) outbreaks.

Methods: Five bibliographic databases were searched for studies reporting clinical features, management, and patient outcomes of mpox. Systematic review and meta-analysis were performed.

Results: In total, 73 studies were included in the systematic review, of which 33 studies were subjected to meta-analysis. Previous outbreaks substantially affected children, whereas the 2022 outbreak primarily affected male adults, of which 94.66% (95% confidence interval [CI], 88.03-98.95) were men who have sex with men. Furthermore, 72.47% (95% CI, 51.04-89.71) reported high-risk sexual activity and the overall human immunodeficiency virus (HIV) prevalence was 37.65% (95% CI, 30.09-45.50). Skin lesions remain the typical symptom; however, their anatomic distribution differed. Systemic manifestations were common, but rectal pain was unique to the 2022 outbreak. The estimated overall fatality during past outbreaks in Africa was 4.61% (95% CI, 2.39%-7.35%), whereas 6.34% (95% CI, 3.35%-10.10%) of patients from the 2022 outbreak required hospitalization. Antiviral treatment, in particular tecovirimat, has been prescribed for a subset of patients, but the efficacy remains inconclusive.

Conclusions: These findings are important for better understanding the disease and guiding adequate response to mpox outbreaks.

Keywords: mpox; outcomes; sexual activity; symptoms; treatment.

Figure 1.

Study selection.

Figure 2.

The incidence rate of MSM in 18 studies included in the analysis. Abbreviations: CI, confidence interval; MSM, men who have sex with men.Complete reference information for the following references Duque et al (2022), Minhaj et al (2022), Miura et al (2022), Patel et al (2022), Peiro-Mestres et al (2022), Martinez et al (2022), Mailhe et al (2022), Caria et al (2022), Cassir et al (2022), Garcia-Piqueras et al (2022), Gaspari et al (2022), Hoffmann et al (2022), Nouchi et al (2022), Nunez et al (2022), Sheffer et al (2022), Caldeira et al (2022) cited in Figure 2 are listed in the Supplementary Material.

Figure 3.

The incidence rate of (A) high-risk sexual activities (condomless/multipartner sexual activity; 5 studies included) and (B) human immunodeficiency virus (HIV) positivity rate (15 studies included) in patients of the 2022 mpox outbreak.Complete reference information for the following references Duque et al (2022), Patel et al (2022), Peiro-Mestres et al (2022), Martinez et al (2022), Mailhe et al (2022), Caria et al (2022), Cassir et al (2022), Garcia-Piqueras et al (2022), Gaspari et al (2022), Hoffmann et al (2022), Nouchi et al (2022), Nunez et al (2022), and Sheffer et al (2022) cited in Figure 3 are listed in the Supplementary Material.

Figure 4.

Comparison of clinical symptoms of patients between (A) the previous (9 studies included) and (B) the 2022 (16 studies included) mpox outbreaks.

Figure 5.

Distribution of skin lesions in patients of the previous and the 2022 outbreaks. A, The distribution of skin lesions in patients from the previous outbreaks (5 studies included). B, The distribution of skin lesions in patients from the 2022 outbreaks (14 studies included).

Figure 6.

Clinical outcomes in patients during the previous and the 2022 outbreaks. A, The fatality rate of patients from major endemic African countries in previous mpox outbreaks (10 studies included). B, The rate of hospitalization in the current outbreak (9 studies included).Complete reference information for the following references Pittman et al (2022), Mukinda et al (1997), Hutin et al (2001), Kalthan et al (2018), Akar et al (2020), Formenty et al (2010), Nakoune et al (2017), Doshi et al (2019), Yinka-Ogunleye et al (2019), Besombes et al (2022), Duque et al (2022), Patel et al (2022), Mailhe et al (2022), Caria et al (2022), Garcia-Piqueras et al (2022), Hoffmann et al (2022), Nunez et al (2022) cited in Figure 6 are listed in the Supplementary Material.