We linked 4 mpox cases in South Ubangi, Democratic Republic of the Congo, to transboundary transmission from Central African Republic. Viral genome sequencing demonstrated that the monkeypox virus sequences belonged to distinct clusters of subclade Ia. This finding demonstrates the borderless nature of mpox and highlights the need for vigilant regional surveillance.
Keywords: Central African Republic; Democratic Republic of the Congo; MPXV; cross-border transmission; monkeypox virus; mpox; sexually transmitted infections; subclade Ia; surveillance; viruses; zoonoses.