Prevalence of Intestinal Parasites in Endangered Ashy Red Colobus Monkeys (Piliocolobus tephrosceles) in Tanzania

Intestinal parasites constitute one of the most frequent causes of gastrointestinal diseases in primates, directly affecting their health. We sampled 3 populations of the Endangered ashy red colobus monkey (Piliocolobus tephrosceles) with different levels of anthropogenic disturbance in Tanzania. We collected faecal samples (n=157) soon after defecation and fixed them in situ in 70% ethanol. We then re-fixed half of each sample in MIF (merthiolate iodine formaline) for microscopic study and saved the rest for molecular analysis. We examined helminth eggs, larvae and protozoan cysts using a light microscope after faecal sedimentation. We analysed samples positive for Giardia using Polymerase Chain Reaction (PCR) to determine genotypes. The overall prevalence of protozoan and helminth infection was 94.3% (148/157), with 64.9% (96/148) being infected by 1 species, 25.7% (38) by 2 species, and 9.5% (14) by 3 or more species. We detected 8 species of intestinal parasites: Ancylostoma sp. (13.4%), Trichuris trichiura (3.8%), Strongyloides stercoralis rhabditoid larvae (2.5%), Entamoeba chatonni (82.8%), Iodamoeba butschlii (14%), Endolimax nana (4.5%), Blastocystis hominis (2.5%) and Giardia duodenalis (14%). These species were detected in different combinations in the 3 areas, while Giardia was detected in only 1 area. The molecular analysis of positive Giardia samples showed that all of them belonged to assemblage B, which could also infect humans. However, we could not identify an exclusively anthropogenic origin of the parasitic species found. Our study contributes to our knowledge of parasitic infections in ashy monkeys in Tanzania, allowing us to assess their health status and disease risk, which in turn will help us design more successful conservation strategies for this Endangered primate in Tanzani