Investigating a Skin Disease in Guinea Baboons (Papio papio) Using Non-invasive Methods

Infectious skin diseases in nonhuman primates are of importance due to their zoonotic transmission potential, especially in biodiversity rich areas where human-wildlife interactions are frequent. Here, we report the presence of a skin disease in unhabituated wild Guinea baboons (Papio papio) inhabiting an agroforest landscape in Cantanhez National Park, Guinea-Bissau, exclusively using non-invasive surveillance methods. We combined 107 georeferenced baboon presence points, camera trap footage obtained during 2224 camera trap days, with molecular analysis of 272 biological samples collected opportunistically. Given the presence of leprosy in western chimpanzees (Pan troglodytes verus) in Cantanhez and yaws in nonhuman primates in Sub-Saharan Africa, we tested the samples using specific PCR protocols for Mycobacterium leprae and Treponema pallidum as possible causative agents. We estimated the minimum ranging area of the baboons, which overlapped with 27.25% of the home range of a chimpanzee community affected by leprosy. We identified at least seven baboons with lesions on the muzzle, eyebrow, ears, tail, hindquarters, joints, hands and/or feet. Clinical signs partially aligned with descriptions of nonhuman primates affected by leprosy and yaws. Molecular analysis failed at conclusively showing the presence of either suspected pathogen. Longitudinal monitoring and additional sampling are needed to identify the causative agent, which may be relevant to conservation and public health, as baboon meat is consumed by humans in Guinea-Bissau.