Non-invasive environmental DNA sampling reveals tuberculosis risks at the human – Great Ape Interface in Africa

The current range of African great apes includes countries with some of the world's highest incidence rates of human tuberculosis (TB). Non-human primates (NHPs) living in their natural habitats are expected to be free of TB. However, TB represents a known threat to captive NHP communities. We applied a non-invasive sponge-based environmental DNA (eDNA) sampling to run a cross-sectional survey at the human-animal interface in a challenging setting: the East of the Democratic Republic of Congo (DRC). The study sites included a primate rehabilitation centre, the local health area, and a nearby national park with critically endangered Eastern Lowland Gorillas (<i>Gorilla beringei graueri</i>). Sponge samples were tested for two PCR targets, IS<i>6110</i> and <i>mpb</i>70. Positive samples were further characterized by spoligotyping, species identification and detection of molecular resistance against rifampicin and isoniazid. We detected <i>Mycobacterium tuberculosis</i> eDNA in 26% of the samples from all three sites including samples linked to humans, wild gorillas and captive NHPs. The spoligotype could be identified in 18 cases. Spoligotype SIT130 was detected in all sites including human and gorilla environment samples. These findings are strongly suggestive of epidemiological links between human and NHP TB in equatorial Africa.