Genetic diversity of adenoviruses in humans and wild non-human primates from the Mabali Reserve (DRC), including a divergent adenovirus cluster in Cercopithecus wolfi

Adenoviruses exhibit substantial genetic diversity in humans and non-human primates (NHPs), yet their occurrence in wild African primates remains incompletely documented. We performed adenovirus DNA detection and genetic diversity in wild NHPs and humans living around the Mabali Forest Reserve, Democratic Republic of Congo, within a One Health framework. We analyzed 630 NHP fecal samples collected in December 2023 and 221 human stool samples from febrile individuals collected in July 2025. NHP species were identified by mitochondrial 16 S rRNA gene sequencing. Adenovirus DNA was screened by qPCR targeting the hexon gene and characterized by partial DNA polymerase gene sequencing and amino acid-based phylogenetic analysis. NHP species were identified in 569/630 (90.3%) samples. Adenovirus DNA was detected in 10/569 (1.76%) samples, including three from Cercopithecus ascanius , six from C. wolfi , and one from Lophocebus aterrimus . Five C. wolfi -derived sequences formed a distinct monophyletic cluster (77% bootstrap support), whereas three C. ascanius -derived sequences clustered near the HAdV-41 reference sequence. In humans, adenovirus DNA was detected in 9/221 (4.1%) stool samples. Human-derived sequences showed genetic affinities with several human adenovirus reference types. The phylogenetic analysis was based on 76 amino acid positions, limiting the resolution of evolutionary relationships. These findings document adenovirus DNA in humans and several wild NHP species, including a distinct phylogenetic cluster associated with C. wolfi . Although genetic affinities with reference adenoviruses were observed, the available data do not establish recent cross-species transmission between the sampled populations. Further genomic characterization and longitudinal surveillance are needed to clarify adenovirus diversity and evolutionary relationships at the human-wildlife interface.