Gastro-intestinal helminths in a natural population ofMacaca sinica andPresbytis spp. at Polonnaruwa, Sri Lanka

Dewit, I.; Dittus, Wolfgang P. J.; Vercruysse, Jozef; Harris, Eileen; Gibson, Dave I.

doi:10.1007/bf02382681

Cited by 18 publications

(22 citation statements)

References 8 publications

(8 reference statements)

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“…Other primate studies have demonstrated through fecal examination similar convex age-infection patterns for each of these parasite genera. For example, S. fuelleborni infections were previously noted to be more prevalent among juvenile Japanese macaques at multiple locations (Horii et al 1982;Gotoh 2000) and toque macaques (Macaca sinica) in Sri Lanka (Dewit et al 1991). Furthermore, Strongyloides spp.…”

Section: Discussionmentioning

confidence: 96%

“…Nonetheless, these models facilitate predictions about the nature of infections in age-structured host populations, such as those found among most primate species. Though age differences in parasitic infection have been found among primates (e.g., Muller-Graf et al 1996;Dewit et al 1991;Gotoh 2000), few studies have considered the implications of such differences to infection dynamics.…”

Section: Introductionmentioning

confidence: 99%

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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: 96%

Section: Introductionmentioning

confidence: 99%

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

2010

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“…These macaques are not managed, and a great deal is known about their demography, development, ecology, behavior, and population genetics because they have been under continuous study for more than 30 yr [Dittus, 1975[Dittus, , 1998Hoelzer et al, 1994]. It has also been shown, for example, that this population is subject to infection from a variety of pathogens, including dengue and other flavi viruses [Peiris et al, 1993;De Silva et al, 1999], protozoa [Ekanayake et al, 2001], and helminth parasites [Dewit et al, 1991]. The hematology of toque macaques has not been studied before.…”

Section: Introductionmentioning

confidence: 99%

Hematology of a natural population of toque macaques (Macaca sinica) at polonnaruwa, Sri Lanka

Ekanayake

Horadagoda

Sanjeevani

et al. 2003

American J Primatol

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Hematological studies were conducted in three wild groups of toque macaques (Macaca sinica) inhabiting the Polonnaruwa Sanctuary in northeastern Sri Lanka. The macaques were temporarily trapped and anesthetized, and femoral blood was drawn from 35 males and 37 females (age range: 0.33-24.5 yr). Statistically significant (P<0.05) differences were observed by sex for total plasma proteins (PP), and by age for red blood cell (RBC) counts, hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular Hb (MCH), mean corpuscular Hb concentration (MCHC), PP, erythrocyte sedimentation rate (ESR), differential and absolute neutrophil counts, differential lymphocyte counts, and absolute eosinophil counts. In general, the results were similar to those reported for other species of colony-bred and free-ranging macaques. However, there also were differences. First, in contrast to earlier studies of nonhuman primates, we examined the hematology of infants. Compared to other age classes, infants (<1 yr old) had lower RBC, Hb, MCHC, and ESR values, and a higher MCV. These findings were similar to those obtained in human infants. Second, we observed variations in hematology among social groups in relation to their ecology. Two groups (IH3 and M3) had ready access to water throughout the dry season (the period of sampling), whereas the third group (J) did not. The Hb, RBC, and PP values obtained in groups IH3 and M3 were similar to those reported in other macaque species. However, these parameters in group J were significantly (P<0.01) higher, which suggests that this group (representing about 26% of the sample) had been dehydrated during the dry season. Finally, two indices indicative of injury and infection--the ESR and leukocyte counts--were higher in the wild toque macaques than has been reported for other species of macaques held in captivity, and about 15% of the toque macaques sampled had extreme outlier values for these parameters; however, none were visibly ill or died. These results suggest that wild toque macaques are subject to a wide array of physical and biological insults that are unique to natural populations.

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“…A number of Asian and African cercopithecines are infected by Streptopharagus spp. (Myers & Kuntz 1965;Dewit et al 1991;Muller-Graf et al 1996;Karere & Munene 2002;Hahn et al 2003;Gillespie et al 2004), while G. pulchrum has been found in a wide range of mammalian hosts, including nonhuman primates and, rarely, humans (Anderson 2000;Acha & Szyfres 2003;Kudo et al 2003;Haruki et al 2005;Roberts & Janovy 2005). Gongylonema pulchrum is therefore the only species to infect Japanese macaques with the potential to be shared with other sympatric mammals, a possibility that to my knowledge has not yet been investigated.…”

Section: The Model Parasitesmentioning

confidence: 99%

Ecology and Epidemiology of Nematode Infection in Japanese Macaques:

MacIntosh

2014

Primate Res.

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Gastro-intestinal helminths in a natural population ofMacaca sinica andPresbytis spp. at Polonnaruwa, Sri Lanka

Cited by 18 publications

References 8 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

Hematology of a natural population of toque macaques (Macaca sinica) at polonnaruwa, Sri Lanka

Ecology and Epidemiology of Nematode Infection in Japanese Macaques:

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