Oesophagostomiasis in non‐human primates of Gombe National Park, Tanzania

Abstract

Oesophagostomum sp. is a parasitic nematode that frequently infects wild chimpanzees. Although nodular lesions are commonly associated with infection, some wild chimpanzee populations seem to tolerate Oesophagostomum nodular lesions while those at Gombe and other sites suffer from associated morbidity and mortality. From August 2004 to December 2013, we examined demographic (i.e., age, sex) and individual correlates (i.e., fecal consistency, Oesophagostomum egg production) to Oesophagostomum-associated pathology in 14 individually recognized chimpanzees at Gombe Stream National Park, Tanzania. In addition, we characterized Oesophagostomum-associated pathology in 14 individual sympatric primates including baboons, colobus, and cercopithecid monkeys. In five chimpanzees, there was no evidence of any significant underlying disease aside from oesophagostomiasis to explain the thin condition or diarrhea. All five of these chimpanzees had moderate to numerous parasitic nodules. In general, nodules were more numerous in older chimpanzees. Three of four chimpanzees with the highest average Oesophagostomum egg counts in feces collected during the year prior to their death had numerous parasitic nodules at necropsy. In contrast, the four chimpanzees with the lowest egg counts had only moderate numbers of nodules. No association (P =0.74) was noted between frequency of diarrhea in the year prior to death and the number of nodules noted at necropsy. Nodules were also present in all baboons examined documenting pathology associated with Oesophagostomum infection in wild baboons. In contrast, no lesions were noted in colobus or cercopithecid monkeys, although it is uncertain if they are infected as no fecal studies have been completed in these species to date at Gombe. Sequence of DNA isolated from nodules in chimpanzees matched (99%) Oesophagostomum stephanostomum. Further research is needed to identify the types of Oesophagostomum causing lesions in baboons and to determine if baboons suffer from these infections.

Molecular characterization of nodule worm in a community of Bornean primates

“…Oesophagostomum-associated pathology in sympatric primates at Gombe reported that, in contrast to chimpanzees and baboons that showed high numbers of nodules, none were found in red colobus (Procolobus rufomitratus) also inhabiting the area (Terio et al, 2018).…”

“…infection in communities of African primates at Mahale, Kibale, and Taï has revealed that not only is the parasite detectable in feces (Ghai, Chapman et al, ; Kooriyama et al, ; Kouassi et al, ), but it may have consequences for individual health. Clinical signs associated with the onset of disease have been observed in both chimpanzees and baboons ( Papio anubis ), and chimpanzees have been observed swallowing whole leaves to purge intestinal worms (Huffman & Caton, ; Huffman et al, ; Terio et al, ). Given that Oesophagostomum spp.…”

“…infection in colobines suggests different host–parasite dynamics than that observed in chimpanzees. A recent study looking at Oesophagostomum ‐associated pathology in sympatric primates at Gombe reported that, in contrast to chimpanzees and baboons that showed high numbers of nodules, none were found in red colobus ( Procolobus rufomitratus ) also inhabiting the area (Terio et al, ). The effect of diet on the establishment and persistence of the parasite could be a venue for future exploration in this regard.…”

“…Despite being common, strongylids such as Oesophagostomum spp. (Nematoda, Strongylida) are often overlooked as a serious concern despite having been shown to cause serious disease in nonhuman primates and humans (Krief et al, ; Polderman & Blotkamp, ; Terio et al, ).…”

Potentially zoonotic gastrointestinal nematodes co-infecting free ranging non-human primates in Kenyan urban centres

“…Oesophagostomum bifurcum is considered as the principal nodular worm of humans (Terio et al, 2018) while Oesophagostomum stephanostomum infects great apes including chimpanzees (Cibot et al, 2015) and gorillas (Makouloutou et al, 2014). Although the potential for cross-transmission of Oesophagostomum spp between humans and NHPs has been disputed (Gruijter et al, 2005;Van Lieshout et al, 2005) a novel Oesophagostomum clade infecting humans and sympatric NHPs populations has been described in Uganda Cibot et al, 2015).…”