Routes of transmission of mpox by virus clade and geographic distribution: A systematic review

Mpox epidemiology has experienced a dramatic change in recent years with a marked shift in transmission dynamics. The objective was to assess the route of transmission of mpox by virus clade and geographic distribution. A systematic review of studies with transmission data published between September 2022 and September 2024 was conducted. A total 222 studies including 45,553 mpox patients were included. Approximately 93.0 % of the patients were males and 98.6 % were adults. Approximately 89.1 % were men who have sex with men, 5.3 % were heterosexual men, and 5.5 % were heterosexual women. Approximately 95.3 % reported sexual contact (65.1 % confirmed and 30.3 % suspected), 2.9 % close non-sexual contact, and 1.8 % multiple/other routes (not including inhalation). Sexual contact represented > 90 % of transmission in all regions but African region. Most studies reported clade data showed clade IIb with a similar transmission pattern as described above. This can support the formulation of infection prevention and control recommendations.