Fig. 1: Drivers of mpox cases in Cameroon and Nigeria.

a, Map of Nigeria and Cameroon, showcasing the ecological setting of zoonotic MPXV. The forest cover is highlighted in green. The border between Nigeria and Cameroon is annotated in red, with the Niger River in Nigeria and Sanaga River in Cameroon highlighted in light blue. Our sampling sites in Cameroon are annotated in orange, and states of interest are annotated with highlighted borders. Sampling sites of zoonotic Nigerian sequences are annotated in blue. NWR, Northwest Region of Cameroon; SWR, Southwest Region of Cameroon. b, Geopolitical regions of Nigeria, with Abia State and Rivers State highlighted with red borders. c, Epidemiological incidence of mpox cases in Nigeria coloured by geopolitical region (top) relative to the temporal and geographic distribution of the Nigerian genomic dataset (bottom). d, Clade IIb phylogeny with reconstructed SNPs mapped onto branches. We performed ancestral state reconstruction across our clade IIb phylogeny to map SNPs to their relevant branches. We annotated APOBEC3 characteristic mutations (CT or GA) in the correct dimer context along branches and calculated their relative proportion across internal branches (f). APOBEC3 mutations along the branches are annotated in yellow and red, with the remainder in grey and black. The hMPXV-1 clade (lineage A) is highlighted in the light blue box, with lineage annotation in text. Our new zoonotic outgroup sequences are annotated as Zx. Our sequences (n = 118) are highlighted as enlarged tips. The lineage sampled from Cameroon and Akwa Ibom in Nigeria is annotated in orange. e, Lineage distribution of our hMPXV-1 sequences. f, The number of APOBEC3 SNPs among all mutations for the zoonotic lineage from Cameroon and Akwa Ibom, the remaining zoonotic subtree (KJ642617 and Zx, annotated in d) and the hMPXV-1 subtree (highlighted and annotated in d).