A contemporary review of clade-specific virological differences in monkeypox viruses

Background: Monkeypox virus (MPXV) is an emerging zoonotic virus that has had on-going public health impacts in endemic regions of Central and West Africa for over a half-century. Historically, the MPXV clade endemic in regions of Central Africa is associated with higher morbidity and mortality as compared with the clade endemic in West Africa.Objectives: Here, we review the virological characteristics of MPXV and discuss potential relationships between virulence factors and clade-(and subclade-) specific differences in virulence and transmission patterns.Sources: Targeted search was conducted in PubMed using ((monkeypox virus) OR (Orthopoxvirus)) AND (zoonosis)) OR ((monkeypox) OR (human mpox).Content: Forty-seven references were considered that included three publicly available data reports and/ or press releases, one book chapter, and 44 published manuscripts. Implications: Although zoonosis has been historically linked to emergence events in humans, epidemi-ological analyses of more recent outbreaks have identified increasing frequencies of human-to-human transmission. Furthermore, viral transmission during the 2022 global human mpox outbreak, caused by a recently identified MPXV subclade, has relied exclusively on human-to-human contact with no known zoonotic link. Tochi Okwor, Clin Microbiol Infect 2023;29:1502 (c) 2023 The Author(s). Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).