Mpox Clade IIb Virus Introduction into Kinshasa, Democratic Republic of the Congo, July 2025.

Abstract

Clade I mpox virus (MPXV) is endemic in the Democratic Republic of the Congo (DRC). Recent studies have described the changing epidemiology of mpox in the country, which has been mainly characterized by the emergence of new MPXV lineages, Clade Ib/sh2023 and Ia/sh2024, associated with sustained human-to-human transmission. Both Clade Ib/sh2023 and Ia/sh2024 are co-circulating in Kinshasa, the capital city of the DRC. Here, we report the first two cases of Clade IIb/sh2017 identified in Kinshasa, DRC, imported from West Africa and locally transmitted. Clinical specimens were collected and tested by PCR. We performed whole genome sequencing using a tiled-amplicon sequencing approach with Clade IIb MPXV-specific primers. The phylogenetic tree shows that Kinshasa Clade IIb MPXV is assigned to Clade IIb/sh2017 within the newly designated lineage G.1, as identified in January 2025 in Sierra-Leone.