Molecular characterization and prevalence of protozoan and metazoan parasites infecting non-human primates in natural and captive conditions.

Background: Non-Human Primates (NHP) have been found infected with a diversity of intestinal zoonotic protozoan and metazoan parasites of public health concern. Blastocystis subtypes have been reported in free-ranging and captive NHP from the New and Old World. Also, Giardia duodenalis assemblages A and B, and Entamoeba species have been reported in NHP. The occurrence of zoonotic helminths has also been recorded in NHP, including Trichuris spp. and Ascaris spp. Ecosystem transformation increases contact between humans and NHP, leading to chances of zoonotic parasite transmission. Likewise, contact with captive primates can represent an occupational risk for humans leading to parasitic infections. This study aims to evaluate the prevalence and genetic diversity of intestinal parasites from NHP living in fragmented forest in Colombia, and in a wildlife recovery centre in Italy, in order to identify potentially zoonotic pathogens and explore its transmission pathways. Methods: We collected fecal samples from free-ranging NHP Alouatta seniculus, Ateles hybridus, Aotus griseimembra, Cebus versicolor, Saimiri cassiquiarensis, and Sapajus sp. living in forest fragments in Central Colombia, as well as samples from captive macaques (Macaca tonkeana) living at Parco Faunistico Piano dell’Abatino, in Rome. Overall, 166 fecal samples were collected from different primate individuals, and faecal smears were performed in order to identify parasites based on morphology. Results: Around 90% of the samples were positive for intestinal parasites. Protozoans (Blastocystis sp., Balantiididae, Dientamoeba sp., Entamoebidae, Giardia sp.), cestodes (Hymenolepis sp.), trematodes (Controrchis sp.), nematodes (Ascarididae, Trichuridae, Strongyloides sp., Trypanoxyuris sp., Ancylostomatidae), and acanthocephalans were found in free-ranging NHP. So far, samples positive for Ascarididae and Blastocystis sp. were characterized using molecular techniques, and Ascaris lumbricoides and Blastocystis hominis were identified. Captive primates were found infected with Entamoeba sp., Oesophagostomum sp., and Balantidium-like cysts. Discussion: This study contributes new information of intestinal parasites infecting wild NHP exposed to anthropogenic disturbance. The finding of parasites with zoonotic potential suggests epidemiological implications in NHP conservation and human health, at the human- NHP interface, in transformed ecosystems. The results of this study could be useful in the design of public health policies, and within NHP conservation programs.