Geographic distribution and epidemiology of Oesophagostomum bifurcum and hookworm infections in humans in Togo.

Pit, D. S. S.; Rijcken, F. E. M.; Raspoort, E. C.; Baéta, S.; Polderman, A. M.

doi:10.4269/ajtmh.1999.61.951

Cited by 29 publications

(20 citation statements)

References 6 publications

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“…In humans, T. trichiura infections are commonly more severe in young children than in adults in areas where the disease is endemic (Bundy et al 1987). Evidence also suggests that prevalence of O. bifurcum peaks in humans in Ghana during early adolescence (Pit et al 1999). Acquired immunity is among the possible mechanisms generating similar patterns in various primate host-nematode parasite associations.…”

Section: Discussionmentioning

confidence: 97%

Host age, sex, and reproductive seasonality affect nematode parasitism in wild Japanese macaques

2010

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Parasites are characteristically aggregated within hosts, but identifying the mechanisms underlying such aggregation can be difficult in wildlife populations. We examined the influence of host age and sex over an annual cycle on the eggs per gram of feces (EPG) of nematode parasites infecting wild Japanese macaques (Macaca fuscata yakui) on Yakushima Island. Five species of nematode were recorded from 434 fecal samples collected from an age-structured group of 50 individually recognizable macaques. All parasites exhibited aggregated EPG distributions. The age-infection profiles of all three directly transmitted species (Oesophagostomum aculeatum, Strongyloides fuelleborni, and Trichuris trichiura) exhibited convex curves, but concavity better characterized the age-infection curves of the two trophically transmitted species (Streptopharagus pigmentatus and Gongylonema pulchrum). There was a male bias in EPG and prevalence of infection with directly transmitted species, except in the prevalence of O. aculeatum, and no sex bias in the other parasites. Infection with O. aculeatum showed a female bias in prevalence among young adults, and additional interactions with sex and seasonality show higher EPG values in males during the mating season (fall) but in females during the birth season (spring). These patterns suggest that an immunosuppressive role by reproductive hormones may be regulating direct, but not indirect, life-cycle parasites. Exposure at an early age may trigger an immune response that affects all nematodes, but trophically transmitted species appear to accumulate thereafter. Although it is difficult to discern clear mechanistic explanations for parasite distributions in wildlife populations, it is critical to begin examining these patterns in host species that are increasingly endangered by anthropogenic threats.

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Section: Discussionmentioning

confidence: 97%

Host age, sex, and reproductive seasonality affect nematode parasitism in wild Japanese macaques

2010

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“…It is likely that human-human transmission is occurring in the endemic areas [37]. Further, in some locations no monkeys are present, thus suggesting that the parasite may not be an obligate zoonotic infection [36].…”

Section: Oesophagostomiasismentioning

confidence: 99%

“…The ®rst reports of infection in humans date back to 1905 [35], but in 1991 Polderman et al [36], reported that the parasite was commonly found in humans in Northern Togo and Ghana. Recent estimates indicate that in these areas over 230 000 individuals carry infection [37].…”

Section: Oesophagostomiasismentioning

confidence: 99%

Emerging helminth zoonoses

McCarthy

Moore

2000

International Journal for Parasitology

209

133

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“…recorded to date from non-human primates, O. bifurcum, O. stephanostomum, and O. aculeatum have also been reported in humans (Chabaud & Lariviere, 1958;Polderman & Blotkamp, 1995). Zoonosis caused by O. bifurcum is endemic in the northernmost part of Ghana and Togo situated in western Africa, and high prevalences of the disease in human residents have been recorded (Blotkamp et al, 1993;Polderman & Blotkamp, 1995;Pit et al, 1999;Yelifari et al, 2005;Gasser et al, 2006). Recently, however, multifaceted genetic analyses have demonstrated that different genotypes of O. bifurcum are prevalent in human patients and local non-human primates (Mona monkeys, Patas monkeys, Green monkeys, and Olive baboons) in Ghana and Togo (de Gruijter et al, 2004(de Gruijter et al, , 2005; reviewed by Gasser et al, 2006Gasser et al, , 2009, supporting parallel assump-HELMINTHOLOGIA, 51, 2: 83 -93, 2014 Prevalence and genetic diversity of Oesophagostomum stephanostomum in wild lowland gorillas at Moukalaba-Doudou National Park, Gabon tions based on epidemiological and morphological analyses de Gruijter et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2014

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Using a sedimentation method, the prevalence of the nodular worm Oesophagostomum stephanostomum (Nematoda: Strongylida) in western lowland gorillas at Moukalaba-Doudou National Park (MDNP), Gabon, was determined in fecal samples collected between January 2007 and October 2011, along with their coprocultures. Concurrently, possible zoonotic Oesophagostomum infections in villagers living near MDNP were assessed from their fecal samples collected during October and November of 2011. In the gorillas, strongylid (Oesophagostomum and/or hookworm) eggs were found in 47 of 235 fecal samples (20.0 %) and Oesophagostomum larvae were detected in 101 of 229 coprocultures (44.1 %). In the villagers, strongylid eggs were found in 9 of 71 fecal samples (12.7 %), but no Oesophagostomum larvae were detected in coprocultures. The internal transcribed spacer (ITS) region of ribosomal RNA gene (rDNA) and cytochrome c oxidase subunit-1 (cox-1) region of mitochondrial DNA (mtDNA) of coprocultured Oesophagostomum larvae were amplified using parasite DNA extracted from 7–25 larvae/sample, cloned into Escherichia coli, and sequenced. Sequenced rDNA contained 353/354-bp long ITS1, 151-bp long 5.8S rDNA, and 227-bp long ITS2. Parts of clones showed variations at 1–3 bases in the ITS1 region at a frequency of 24/68 (35.3 %) and at 1–2 bases in the ITS2 region at a frequency of 7/68 (10.3 %), whereas the 5.8S rDNA was essentially identical. Sequenced cox-1 gene of the parasites, 849 bp in length, showed a higher number of nucleotide variations, mainly at the third nucleotide position of the codon. The majority of clones (27/41 (65.9 %)) had an identical amino acid sequence. These results suggest that at MDNP, Gabon, only a single population of O. stephanostomum with a degree of genetic diversity is prevalent in western lowland gorillas, without zoonotic complication in local inhabitants. The possible genetic variations in the ITS region of rDNA and cox-1gene of mtDNA presented here may be valuable when only a limited amount of material is available for the molecular species diagnosis of O. stephanostomum.

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Geographic distribution and epidemiology of Oesophagostomum bifurcum and hookworm infections in humans in Togo.

Cited by 29 publications

References 6 publications

Host age, sex, and reproductive seasonality affect nematode parasitism in wild Japanese macaques

Host age, sex, and reproductive seasonality affect nematode parasitism in wild Japanese macaques

Emerging helminth zoonoses

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

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