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

ABSTRACT

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, epidemiological 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.