Evidence of monkeypox virus clade IIb lineage A.2.2 in the Republic of the Congo and co-circulation of clade Ia, Ib and clade IIb
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.
Authors
- Claude Kwe Yinda (ORCID: https://orcid.org/0000-0002-5195-5478)
- Fabien Roch Niama (ORCID: https://orcid.org/0000-0003-3843-9396)
- Léadisaelle Hosanna Lenguiya (ORCID: https://orcid.org/0009-0004-1617-5689)
- Avelin F. Aghokeng (ORCID: https://orcid.org/0000-0002-1414-0237)
- Félix Koukouikila-Koussounda (ORCID: https://orcid.org/0009-0006-6543-0839)
- Igor Louzolo
- Jordy Exaucé Lyelet Demboux
- Ghislain Dzeret Indolo
- Lucette Nathalie Macosso
- Bani Reize Vishnou Ampiri
- Dachel Aymard Eyenet Boussam
- Reiche Golmard Elenga (ORCID: https://orcid.org/0009-0005-2684-4273)
- Pembe Issamou Mayangue
- Isaac Samuel Onyakouang
- Aristide Gilbert Nianga
- Vincent Jacobus Munster
- Jean Medar Kankou
Institutions
- Maladies Infectieuses et Vecteurs: Écologie, Génétique, Évolution et Contrôle (FR)
- Laboratoire National de Santé Publique du Congo (CG)
- Centre Hospitalier et Universitaire de Brazzaville (CG)
- National Institute of Allergy and Infectious Diseases (US)
- World Health Organization Regional Office for Africa (CG)
- Marien Ngouabi University (CG)
Publication Details
- Journal
- Nature Medicine
- Published
- 2026-04-03
- DOI
- https://doi.org/10.1038/s41591-026-04256-2
- Primary Topic
- Poxvirus research and outbreaks
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- U.S. Department of Health and Human Services
- National Institutes of Health
- Centers for Disease Control and Prevention