Oesophagostomum stephanostomum causing parasitic granulomas in wild chimpanzees (Pan troglodytes verus) of Taï National Park, Côte d'Ivoire.

Nematodes belonging to the genus Oesophagostomum frequently infect wild chimpanzees (Pan troglodytes) across widely separated field sites. Nodular lesions (granulomas) containing Oesophagostomum are commonly seen in the abdomen of infected chimpanzees post‐mortem. At Taï National Park, Côte d'Ivoire, previous studies have identified larvae of a variety of Oesophagostomum spp. in wild chimpanzee stool, based on sequencing of larval DNA, and nodular lesions associated with Oesophagostomum, identified morphologically to the genus level but not sequenced. Here we present three recent cases of parasitic granulomas found post‐mortem in chimpanzees at Taï. We complement descriptions of gross pathology, histopathology and parasitology with PCR and sequencing of DNA isolated from the parasitic nodules and from adult worms found inside the nodules. In all three cases, we identify Oesophagostomum stephanostomum as the causative agent. The sequences from this study were identical to the only other published sequences from nodules in nonhuman primates—those from the wild chimpanzees of Gombe, Tanzania. Research highlights: Chimpanzees in Taï National Park (Côte d'Ivoire) commonly have a small number of abdominal parasitic nodules, observed post‐mortem.A variety of Oesophagostum spp. has been found in the stool of Taï chimps.The nodules are caused by Oesophagostomum stephanostomum, and the ITS‐2 sequence is identical to the only other sequence obtained from chimp nodules (in Gombe, Tanzania). [ABSTRACT FROM AUTHOR]