Gastrointestinal parasites of mountain gorillas (Gorilla gorilla beringei)in the Parc National des Volcans, Rwanda

Ninety-eight fecal samples were collected from 74 free-living mountain gori llas (Gorilla gorilla beringei) from the pare National des Volcans. Rwanda. between July 1995 and January 1997 and examined for parasites by Sheather' s sugar and zinc sulfate flotation methods, trichrome staining, and larval cultures. All samples contained at least one parasite. Seventeen endoparasi tes were identified. including eight protozoa, seven nematodes. one cestode , and one trematode. Two species of arthropod mite were also recovered from the fecal samples. Parasites observed on fecal examinations included stron gyle/trichostrongyle-type: eggs (72/74) (representing Oesphagostomum sp., T richostrongylus sp.. Hyostrongylus spp., and possibly Murshidia sp.), Stron gyloides sp. (1/74), Trichuris trichiura (2/74), Probstmayria sp. (7/74), A noplocephala sp. (63/74), Entamoeba hartmanni cysts and trophozoites (19/70 ), Endolimax nana cysts (31/70). Iodamoeba buetschlii cysts (11/70), Endoli max nana or Iodamoeba buetschlii trophozoites (63/70), Entamoeba coli cysts and trophozoites (14/70), Entamoeba histolytic trophozoite (1/70). Chiloma stix sp. cysts and trophozoites (31/70). and Giardia sp. cysts (2/70). In a ddition, one ascarid and one trematode egg were seen. There were no signifi cant differences in the prevalence of parasites between males and females a nd between age groups; however infants and juveniles appeared to have a low er prevalence of Anoplocephala gorillae. and the silverbacked males appeare d to have a higher prevalence of Probstmayria sp. Parasite prevalence was c onsistent among the five social groups studied except Susa group had a sign ificantly lower prevalence of Anoplocephala gorillae. Trichuris trichiura, Strongyloides sp.. Chilomastix sp.. and Endolimax nana were identified for the first time in this population. and it is possible that these parasites were of human origin. Although there were no obvious clinical effects due t o the presence of these parasites, six parasites identified (Trichuris tric hiura. Strongyloides sp.. Oesphagostomum sp., Trichostrongylus sp.. Entamoe ba histolytica, and Giardia sp.) could potentially be pathogenic. Some of t he parasite products and cultured larvae could not be speciated.