Clinical and pathologic manifestation of oesophagostomosis in African great apes: does self‐medication in wild apes influence disease progression?

Abstract

Nodular worms (Oesophagostomum spp.) are common intestinal parasites found in cattle, pig, and primates including humans. In human, they are responsible for serious clinical disease called oesophagostomosis resulting from the formation of granulomas, caseous lesions or abscesses in intestinal walls. In wild great apes, the fecal prevalence of this parasite is high, but little information is available concerning the clinical signs and lesions associated. In the present study, we describe six cases of multinodular oesophagostomosis in free-ranging and ex-captive chimpanzees and captive gorillas caused by Oesophagostomum stephanostomum. While severe clinical signs associated with this infection were observed in great apes raised in sanctuaries, nodules found in wild chimpanzees do not seem to affect their health status. One hypothesis to explain this difference would be that in wild chimpanzees, access to natural environment and behavior such as rough leaves swallowing combined with ingestion of plants having pharmacological properties would prevent severe infection and decrease potential symptoms.

Prevalence and genetic diversity of Oesophagostomum stephanostomum in wild lowland gorillas at Moukalaba-Doudou National Park, Gabon

“…Nematodes of the genus Oesophagostomum, termed nodular worms, cause oesophagostomiasis characterized by granuloma formation, caseous lesions or abscesses around encapsulated larvae in the intestinal wall of suids, ruminants, primates, and African rodents (Chabaud & DuretteDesset, 1974;Lichtenfels, 1980;Stewart & Gasbarre, 1989;Anderson, 1992;Polderman & Blotkamp, 1995;Krief et al, 2008). Clinical oesophagostomiasis is evident worldwide in domestic animals and focally or sporadically in humans (Stewart & Gasbarre, 1989;Polderman & Blotkamp, 1995).…”

Lignes directrices pour de meilleures pratiques en matière de suivi de la santé et de contrôle des maladies des populations de grands singes

“…Alors que le ver nodulaire (Oesophagostomum spp.) est commun chez les chimpanzés (Gillespie et al 2010 ;Zommers et al 2013), il n'est pas souvent pathogène : les chimpanzés ayant des vers nodulaires en Ouganda et en Côte d'Ivoire ne montrent pas de signes cliniques (Krief et al 2008) tandis que les chimpanzés du PN de Gombe et du PN de Mahale en Tanzanie souffrent de maladies liées aux vers nodulaires (Huffman et al 1997). De façon similaire, les vers Mammomonogamus sp.…”

Ecology and Epidemiology of Nematode Infection in Japanese Macaques:

“…For example, Oesophagostomum spp. can be associated with significant pathology because juvenile stages of these parasites encyst during development and cause nodules in the intestinal mucosa, which eventually burst open to release adult forms of the parasite (Huffman et al 1997;Anderson 2000;Huffman & Caton 2001;Storey et al 2001;Acha & Szyfres 2003;Ziem et al 2005;Krief et al 2008). Strongyloides spp.…”