Uses and limitations of faecal egg count for assessing worm burden in wild boars

Gassó, Diana; Feliu, Cales; David, Frank; Mentaberre, Gregorio; Casas-Díaz, Encarna; Velarde, Roser; Fernández-Aguilar, Xavier; Colom-Cadena, Andreu; Navarro-González, Nora; López‐Olvera, Jorge Ramón; Lavı́n, Santiago; Fenández-Llario, Pedro; Segalés, Joaquím; Serrano, Emmanuel

doi:10.1016/j.vetpar.2015.02.006

Cited by 30 publications

(25 citation statements)

References 12 publications

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“…Faecal egg counts or egg burden are often used to assess parasite burdens but have inherent pitfalls as they are subject to numerous variables that confound cause-effect relationships [43]. The few studies that have ever correlated egg burden to worm burdens have had variable outcomes [44][45][46][47]. Therefore, we believe that care should be taken with egg burden values we recorded from elephants since they may not correspond to the total worm burdens.…”

Section: Discussionmentioning

confidence: 99%

Patterns of helminth infection in Kenyan elephant populations

et al. 2020

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Background: The dynamics of helminth infection in African elephant populations are poorly known. We examined the effects of age, sex, social structure and the normalized difference vegetation index (NDVI) as primary drivers of infection patterns within and between elephant populations. Methods: Coprological methods were used to identify helminths and determine infection patterns in distinct elephant populations in Maasai Mara National Reserve, Tsavo East National Park, Amboseli National Park and Laikipia-Samburu Ecosystem. Gaussian finite mixture cluster analyses of egg dimensions were used to classify helminth eggs according to genera. Generalized linear models (GLM) and Chi-square analyses were used to test for variation in helminth infection patterns and to identify drivers in elephant populations. Results: Helminth prevalence varied significantly between the studied populations. Nematode prevalence (96.3%) was over twice as high as that of trematodes (39.1%) in elephants. Trematode prevalence but not nematode prevalence varied between populations. Although we found no associations between helminth infection and elephant social groups (male vs family groups), the median helminth egg output (eggs per gram, epg) did vary between social groups: family groups had significantly higher median epg than solitary males or males in bachelor groups. Young males in mixed sex family groups had lower epg than females when controlling for population and age; these differences, however, were not statistically significant. The average NDVI over a three-month period varied between study locations. Cluster analyses based on egg measurements revealed the presence of Protofasciola sp., Brumptia sp., Murshidia sp., Quilonia sp. and Mammomonogamus sp. GLM analyses showed that the mean epg was positively influenced by a three-month cumulative mean NDVI and by social group; female social groups had higher epg than male groups. GLM analyses also revealed that epg varied between elephant populations: Samburu-Laikipia elephants had a higher and Tsavo elephants a lower epg than Amboseli elephants. Conclusions: Elephants had infection patterns characterized by within-and between-population variation in prevalence and worm burden. Sociality and NDVI were the major drivers of epg but not of helminth prevalence. Gastrointestinal parasites can have a negative impact on the health of wild elephants, especially during resource scarcity. Thus, our results will be important when deciding intervention strategies.

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Section: Discussionmentioning

confidence: 99%

Patterns of helminth infection in Kenyan elephant populations

et al. 2020

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“…Faecal egg counts (FEC) face criticism regarding their accuracy in quantifying parasite load (Villanua et al ., ; Gasso et al ., ). Egg shedding can vary with the life stage of the parasite, environmental and host conditions (Dorchies et al ., ; Villanua et al ., ; Raharivololona & Ganzhorn, ).…”

Section: Methodsmentioning

confidence: 99%

“…If inbreeding impacts immunocompetency in the banded mongoose, as it does in other mammals (Charpentier et al, 2008) and birds (Reid et al, 2003;Whiteman et al, 2006), we would therefore expect to see Dipylidium and/or Isospora loads co-vary with inbreeding coefficient. Faecal egg counts (FEC) face criticism regarding their accuracy in quantifying parasite load (Villanua et al, 2006;Gasso et al, 2015). Egg shedding can vary with the life stage of the parasite, environmental and host conditions (Dorchies et al, 1997;Villanua et al, 2006;Raharivololona & Ganzhorn, 2010).…”

Section: Parasitology Methodsmentioning

confidence: 99%

Heterozygosity but not inbreeding coefficient predicts parasite burdens in the banded mongoose

et al. 2016

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Inbreeding, reproduction between relatives, often impinges on the health and survival of resulting offspring. Such inbreeding depression may manifest itself through immunological costs as inbred individuals suffer increased propensity to disease, infection and parasites compared to outbred conspecifics. Here, we assess how the intestinal parasite loads of wild banded mongooses (Mungos mungo) vary with pedigree i reedi g oeffi ie t ƒ a d sta dardized ulti-locus heterozygosity. We find a significant association between increased heterozygosity and lower parasite loads; ho e er, this orrelatio does ot sta d he o sideri g ƒ. Su h fi di gs may be explained by local genetic effects, linkage between genetic markers and genes influencing parasite burdens. Indeed, we find heterozygosity at certain loci to correlate with parasite load. Although these tentative local effects are lost following multiple test correction, they warrant future investigation to determine their strength and impact. We also suggest frequent inbreeding within banded mongooses may ea heteroz gosit is a etter predi tor of i reedi g tha pedigree ƒ. This is because inbreeding facilitates linkage disequilibrium, increasing the chances of neutral markers representing genome-ide heteroz gosit . Fi all , either ƒ or heterozygosity had a significant influence on the loads of two specific gastrointestinal parasites. Nevertheless, more heterozygous individuals benefited from reduced overall parasitic infection and genetic diversity appears to explain some variation in parasite burdens in the banded mongoose.

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“…The accuracy of larval counts for diagnosing infection, in fact, may be limited by density‐dependent responses in parasite fertility, host control of parasite fertility through immune‐response or body conditions (Byrne, Fogarty, Mooney, Marples, & Holland, ). Results of coprological analyses, however, significantly and positively correlate to adult parasite burdens in wild species (Byrne et al, ; Gassó et al, ) and are often used as a proxy of parasite infection.…”

Section: Methodsmentioning

confidence: 99%

“…Lung parasites causing bronchopulmonary strongylosis be- TA B L E 1 90% fixed kernel density (90KDE) home range, proportion of intrasexual interactions won and mating behavior of adult male chamois (n = 22) resulting from cluster analysis (see Appendix S1) during the 2011 rut in Gran Paradiso National Park frequently (Taylor et al, 2008 (Byrne et al, 2018;Gassó et al, 2015) and are often used as a proxy of parasite infection.…”

Section: Larval Countsmentioning

confidence: 99%

Parasitism and alternative reproductive tactics in Northern chamois

Corlatti

Lorenzetti

Bassano

2019

Ecology and Evolution

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Alternative reproductive tactics (ARTs), discrete phenotypic variations evolved to maximize fitness, may entail different cost‐benefit trade‐offs. In large mammals, differences in costs associated with ARTs—including energy expenditure and parasite infection—are typically greatest during the breeding season. Nonetheless, physiological and behavioral differences between ARTs can manifest throughout the year, possibly involving costs that may contribute to maintain ARTs within populations. Using the number of nematode larvae per gram of feces (LPG) as a proxy, we explored the temporal changes in lung parasite infection in territorial and nonterritorial male chamois Rupicapra in the Gran Paradiso National Park (Italy), between 2011 and 2012. We aimed to identify which tactic‐specific physiological and behavioral features (including age, hormonal levels, inter‐ and intrasexual interactions, and space use) or climatic factors (temperature and precipitation) best explained yearly variation in parasite infection within and between ARTs. Generalized additive mixed models showed that the fecal larval counts of lung nematodes underwent strong temporal changes in both male types. Differences between ARTs (with higher LPG values in territorial than nonterritorial males) were greatest during the rut and—to a lesser extent—in spring, respectively, at the peak and at the onset of territoriality. The difference in LPG between tactics was largely explained by the greater levels of hormone metabolites in territorial males during the rut. The other variables did not contribute significantly to explain the different shedding of larvae within and between ARTs. Our analysis suggests that different values of LPG between territorial and nonterritorial males are largely a result of tactic‐specific differences in the secretion of hormone metabolites, but only during the rut. To clarify whether rut‐related parasitism contributes to the maintenance of ARTs, tactic‐specific life history trade‐offs, for example, between reproduction and parasite‐related mortality, must be investigated.

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Uses and limitations of faecal egg count for assessing worm burden in wild boars

Cited by 30 publications

References 12 publications

Patterns of helminth infection in Kenyan elephant populations

Patterns of helminth infection in Kenyan elephant populations

Heterozygosity but not inbreeding coefficient predicts parasite burdens in the banded mongoose

Parasitism and alternative reproductive tactics in Northern chamois

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