Sharing without Caring: High Prevalence and Similarity of Potentially Zoonotic Gastrointestinal Helminths in Two Sympatric Nonhuman Primates in a Tropical Resource Reserve

Abstract

Nonhuman primates (NHPs) are threatened globally, with infectious diseases ranking among the major threat factors. NHPs may also harbor zoonotic pathogens that may spillover to humans, making the surveillance of infectious diseases and parasite infestations in NHPs of conservation and public health important. Here, we assessed the gastrointestinal helminths of sympatric green monkeys and olive baboons at the Shai Hill Resource Reserve (SHRR) in Accra, Ghana. Examination of 60 fecal samples from the two NHPs using direct wet mount preparations, formol-ether sedimentation, and zinc-sulfate centrifugal flotation techniques yielded 12 gastrointestinal helminth species comprising nine nematodes, two cestodes, and one trematode. Nine of the helminth species (6 nematodes, 2 cestodes, and 1 trematode) were common to the baboons and green monkeys, giving a high (86%) similarity of helminth composition between the two NHPs. The overall prevalence of gastrointestinal helminth infestations was significantly higher (p=0.0002) in olive baboons (100%) than in green monkeys (86.7%). The prevalence of Enterobius sp. (χ2 = 30.03, p≤0.00001) and Strongyloides sp. (χ2 = 19.53, p≤0.0001) was significantly higher in green monkeys, while Oesophagostomum sp. (χ2 = 36.33, p≤0.0001) was more prevalent in olive baboons. The occurrence of Taenia sp., Dipylidium sp., and Chabertia sp. in the NHPs suggests potential cross-transmission of helminths between the NHPs, and both livestock and domestic animals within the fringe communities of SHRR. Ascaris sp., Enterobius sp., Oesophagostomum sp., Strongyloides sp., and Trichuris sp. in the NHPs are of public health interest because of their zoonotic nature. Our findings provide valuable baseline data for long-term monitoring of the health of NHPs and their habitat and can inform conservation measures that safeguard wildlife, veterinary, and public health.