Concurrent Clade I and Clade II Monkeypox Virus Circulation, Cameroon, 1979-2022

Dd Djuicy (1) , Sa Sadeuh-Mba (1) , Cn Bilounga (2, 3) , Mg Yonga (1) , Jb Tchatchueng-Mbougua (1) , Gd Essima (1) , L Esso (2, 4) , Ime Nguidjol (2) , Sf Metomb (2) , C Chebo (2) , Sm Agwe (2) , Pa Ankone (2) , Fnn Ngonla (2) , Hm Mossi (2) , Agm Etoundi (2) , Si Eyangoh (1) , M Kazanji (1) , R. Njouom (1)

1 Centre Pasteur du Cameroun
2 Ministère de la Santé Publique [Yaoundé, Cameroun]
3 Université de Douala
4 UBA - University of Bamenda [Bamenda, Cameroon]

During 1979–2022, Cameroon recorded 32 laboratory-confirmed mpox cases among 137 suspected mpox cases identified by the national surveillance network. The highest positivity rate occurred in 2022, indicating potential mpox re-emergence in Cameroon. Both clade I (n = 12) and clade II (n = 18) monkeypox virus (MPXV) were reported, a unique feature of mpox in Cameroon. The overall case-fatality ratio of 2.2% was associated with clade II. We found mpox occurred only in the forested southern part of the country, and MPXV phylogeographic structure revealed a clear geographic separation among concurrent circulating clades. Clade I originated from eastern regions close to neighboring mpox-endemic countries in Central Africa; clade II was prevalent in western regions close to West Africa. Our findings suggest that MPXV re-emerged after a 30-year lapse and might arise from different viral reservoirs unique to ecosystems in eastern and western rainforests of Cameroon.

Mots clés: Cameroon; Central Africa; MPXV; Mpox; West Africa; clade I; clade II; concurrent circulation; epidemiology; forest; geographic segregation; monkeypox virus; surveillance; surveillance system; viruses; zoonoses.

Domaines: Virologie

Dd Djuicy, Sa Sadeuh-Mba, Cn Bilounga, Mg Yonga, Jb Tchatchueng-Mbougua, et al.. Concurrent Clade I and Clade II Monkeypox Virus Circulation, Cameroon, 1979-2022. Emerging Infectious Diseases, 2024, 30 (3), pp.432-443. ⟨10.3201/eid3003.230861⟩. ⟨pasteur-04669695⟩