Molecular epidemiology, transmission and clinical features of 2022-mpox outbreak: A systematic review

Health Sci Rep. 2023 Oct 5;6(10):e1603. doi: 10.1002/hsr2.1603. eCollection 2023 Oct.

Abstract

Background and aims: The 2022-mpox outbreak has spread worldwide in a short time. Integrated knowledge of the epidemiology, clinical characteristics, and transmission of mpox are limited. This systematic review of peer-reviewed articles and gray literature was conducted to shed light on the epidemiology, clinical features, and transmission of 2022-mpox outbreak.

Methods: We identified 45 peer-reviewed manuscripts for data analysis. The standards of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) Statement and Cochrane Collaboration were followed for conducting the study.

Results: The case number of mpox has increased about 100 times worldwide. About 99% of the cases in 2022 outbreak was from non-endemic regions. Men (70%-98% cases) were mostly infected with homosexual and bisexual behavior (30%-60%). The ages of the infected people ranged between 30 and 40 years. The presence of HIV and sexually transmitted infections among 30%-60% of cases were reported. Human-to-human transmission via direct contact and different body fluids were involved in the majority of the cases (90%-100%). Lesions in genitals, perianal, and anogenital areas were more prevalent. Unusually, pharyngitis (15%-40%) and proctitis (20%-40%) were more common during 2022 outbreak than pre-2022 outbreaks. Brincidofovir is approved for the treatment of smallpox by FDA (USA). Two vaccines, including JYNNEOSTM and ACAM2000®, are approved and used for pre- and post-prophylaxis in cases. About 100% of the cases in non-endemic regions were associated with isolates of IIb clade with a divergence of 0.0018-0.0035. Isolates from B.1 lineage were the most predominant followed by B.1.2 and B.1.10.

Conclusion: This study will add integrated knowledge of the epidemiology, clinical features, and transmission of mpox.

Keywords: clinical features; epidemiology; monkeypox; transmission.