Clinical review of human mpox

Historically, human mpox was predominantly a zoonotic disease occurring more frequently in rural children in Africa and characterized by a largely self-limiting febrile centrifugal monomorphic rash illness. However, the 2022 mpox global outbreak has shown that the disease is changing in many ways, including sustained human-to-human transmission via sexual contact, novel clinical presentations, and adverse associations between mpox and advanced HIV.

The aim of this paper is to review the traditional and emerging clinical aspects of human mpox and provide updated information on the clinical course and outcome of the disease.

We searched electronic databases including PubMed and Google Scholar and identified relevant published literature on mpox.

The clinical presentation of human mpox is influenced by the route of infectious exposure, the strain and dose of the infecting virus, and the host immune system. Exposure to the virus can result in sub-clinical or clinical diseases of variable severity. Infections caused by clade I viral strains are more severe than class IIa and IIb strains, which are associated with a milder febrile rash illness, and with anogenital skin lesions in clade IIb infections. Most cases of mpox recover entirely within 2-4 weeks after onset of illness and a few develop skin-related sequelae. Overall, people with advanced HIV infection, children <5 years of age, and pregnant women may present with more severe disease and higher case fatalities.

The continued endemicity of the classical mpox in Africa, the emergence of a new clinical form of the disease during the 2022 global outbreak, and the adverse associations between advanced HIV and mpox have implications for the surveillance, clinical diagnosis, and management of human mpox.