Abstract In 2022, monkeypox virus (MPXV) clade IIb emerged resulting in a global epidemic driven by human-to-human transmission, mostly through sexual contact mainly among the population of men who have sex with men. To date, published data on the circulation of MPXV clade IIb in the central African region are absent. Here we describe a case of laboratory-confirmed mpox clade IIb lineage A2.2 in Pointe-Noire, the second largest city of the Republic of the Congo. Whole-genome phylogenetic analysis placed the MPXV in clade IIb, lineage A.2.2 currently emerging in West Africa, in particular Sierra Leone. An additional 16 cases of clade Ia, 32 cases of clade Ib and one additional introduction of clade IIb were identified by passive surveillance in the Republic of the Congo in 2025. The detection of clade IIb mpox marks the third distinct MPXV clade and lineage co-circulating in the human population, together with clade Ia and Ib. This underscores the need for improved surveillance and diagnostic strategies to identify the respective clade and lineage circulating in the human population. Strengthening of regional capacity for case detection, contact-tracing, public health measures and affordable vaccines are urgently needed to reduce the global risk for both clade I and clade II MPXV.
Koukouikila-Koussounda et al. (2026) studied this question.