Abstract Background Mpox is caused by mpox virus and comprises distinct clades with differing clinical and epidemiologic profiles. Clade I (Ia, Ib) predominates in Central Africa, and clade IIb drove the 2022–2023 global outbreak. This review assessed clinical presentation, transmissibility, and virulence of mpox in African settings by viral clade. Methods Searches of PubMed/MEDLINE, PubMed Central, Scopus, Cochrane Library, and Google Scholar identified studies from January 2023 to May 2025. Titles and abstracts were screened in Rayyan by two reviewers, with conflicts resolved by a third. Literature search was conducted between July to August 2025. Eligible designs included cohort studies, case series, case reports, and surveillance reports with clade assignment and clinical or transmission data. Risk of bias was appraised with the JBI tools. Data were synthesized narratively. PRISMA guidelines were followed. Results Ten studies from the Democratic Republic of Congo, Burundi, Uganda, Kenya, and Nigeria met inclusion criteria. Four were cohort designs and six were case reports or case series. Sample sizes ranged from 1 to 850. Reported clades were Ia, Ib, and clade I unspecified; several reports also described clade IIb-linked contexts. Rash was the most consistent symptom, reported in 80–100% of cases. Reported transmission routes included sexual contact, close non-sexual contact, household exposure, travel-related exposure, and vertical transmission confirmed by placental PCR in two studies. Adverse outcomes were frequent in pregnancy, with fetal loss reported in 50–67% in small series. Deaths occurred among people with untreated or advanced HIV infection. Conclusion The reviewed evidence further affirms the dominant role of sexual transmission in current African outbreaks, contrasting with earlier assumptions of predominantly zoonotic or household spread. Strengthening surveillance systems that can distinguish mpox clades and track their clinical patterns is essential to guiding effective public health responses.
Fallah et al. (Tue,) studied this question.