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Cuenca PR, Key S, Jumail A, Surendra H, Ferguson HM, Drakeley CJ, Fornace K. Epidemiology of the zoonotic malaria Plasmodium knowlesi in changing landscapes. ADVANCES IN PARASITOLOGY 2021; 113:225-286. [PMID: 34620384 DOI: 10.1016/bs.apar.2021.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Within the past two decades, incidence of human cases of the zoonotic malaria Plasmodium knowlesi has increased markedly. P. knowlesi is now the most common cause of human malaria in Malaysia and threatens to undermine malaria control programmes across Southeast Asia. The emergence of zoonotic malaria corresponds to a period of rapid deforestation within this region. These environmental changes impact the distribution and behaviour of the simian hosts, mosquito vector species and human populations, creating new opportunities for P. knowlesi transmission. Here, we review how landscape changes can drive zoonotic disease emergence, examine the extent and causes of these changes across Southeast and identify how these mechanisms may be impacting P. knowlesi dynamics. We review the current spatial epidemiology of reported P. knowlesi infections in people and assess how these demographic and environmental changes may lead to changes in transmission patterns. Finally, we identify opportunities to improve P. knowlesi surveillance and develop targeted ecological interventions within these landscapes.
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Affiliation(s)
- Pablo Ruiz Cuenca
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Stephanie Key
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Henry Surendra
- Eijkman-Oxford Clinical Research Unit, Jakarta, Indonesia; Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Heather M Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, Scotland, United Kingdom
| | - Chris J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kimberly Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom; Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, Scotland, United Kingdom.
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Herczeg D, Ujszegi J, Kásler A, Holly D, Hettyey A. Host-multiparasite interactions in amphibians: a review. Parasit Vectors 2021; 14:296. [PMID: 34082796 PMCID: PMC8173923 DOI: 10.1186/s13071-021-04796-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/20/2021] [Indexed: 01/15/2023] Open
Abstract
Parasites, including viruses, bacteria, fungi, protists, helminths, and arthropods, are ubiquitous in the animal kingdom. Consequently, hosts are frequently infected with more than one parasite species simultaneously. The assessment of such co-infections is of fundamental importance for disease ecology, but relevant studies involving non-domesticated animals have remained scarce. Many amphibians are in decline, and they generally have a highly diverse parasitic fauna. Here we review the literature reporting on field surveys, veterinary case studies, and laboratory experiments on co-infections in amphibians, and we summarize what is known about within-host interactions among parasites, which environmental and intrinsic factors influence the outcomes of these interactions, and what effects co-infections have on hosts. The available literature is piecemeal, and patterns are highly diverse, so that identifying general trends that would fit most host–multiparasite systems in amphibians is difficult. Several examples of additive, antagonistic, neutral, and synergistic effects among different parasites are known, but whether members of some higher taxa usually outcompete and override the effects of others remains unclear. The arrival order of different parasites and the time lag between exposures appear in many cases to fundamentally shape competition and disease progression. The first parasite to arrive can gain a marked reproductive advantage or induce cross-reaction immunity, but by disrupting the skin and associated defences (i.e., skin secretions, skin microbiome) and by immunosuppression, it can also pave the way for subsequent infections. Although there are exceptions, detrimental effects to the host are generally aggravated with increasing numbers of co-infecting parasite species. Finally, because amphibians are ectothermic animals, temperature appears to be the most critical environmental factor that affects co-infections, partly via its influence on amphibian immune function, partly due to its direct effect on the survival and growth of parasites. Besides their importance for our understanding of ecological patterns and processes, detailed knowledge about co-infections is also crucial for the design and implementation of effective wildlife disease management, so that studies concentrating on the identified gaps in our understanding represent rewarding research avenues. ![]()
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Affiliation(s)
- Dávid Herczeg
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, Herman Ottó út 15, Budapest, 1022, Hungary.
| | - János Ujszegi
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, Herman Ottó út 15, Budapest, 1022, Hungary
| | - Andrea Kásler
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, Herman Ottó út 15, Budapest, 1022, Hungary.,Department of Systematic Zoology and Ecology, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
| | - Dóra Holly
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, Herman Ottó út 15, Budapest, 1022, Hungary.,Department of Systematic Zoology and Ecology, Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
| | - Attila Hettyey
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, Herman Ottó út 15, Budapest, 1022, Hungary.,Department of Ecology, Institute for Biology, University of Veterinary Medicine, Rottenbiller utca 50, Budapest, 1077, Hungary
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3
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Peterson AC, Ghersi BM, Riegel C, Wunder EA, Childs JE, Blum MJ. Amplification of pathogenic Leptospira infection with greater abundance and co-occurrence of rodent hosts across a counter-urbanizing landscape. Mol Ecol 2020; 30:2145-2161. [PMID: 33107122 DOI: 10.1111/mec.15710] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 10/12/2020] [Accepted: 10/15/2020] [Indexed: 01/20/2023]
Abstract
Land use change can elevate disease risk by creating conditions beneficial to species that carry zoonotic pathogens. Observations of concordant global trends in increased pathogen prevalence or disease incidence and landscape change have generated concerns that urbanization could increase transmission risk of some pathogens. Yet host-pathogen relationships underlying transmission risk have not been well characterized within cities, even where contact between humans and species capable of transmitting pathogens of concern occurs. We addressed this deficit by testing the hypothesis that areas in cities experiencing greater population loss and infrastructure decline (i.e., counter-urbanization) can support a greater diversity of host species and a larger and more diverse pool of pathogens. We did so by characterizing pathogenic Leptospira infection relative to rodent host richness and abundance across a mosaic of abandonment in post-Katrina New Orleans (Louisiana, USA). We found that Leptospira infection loads were highest in areas that harboured increased rodent species richness (which ranged from one to four rodent species detected). Areas with greater host co-occurrence also harboured a greater abundance of hosts, including the host species most likely to carry high infection loads, indicating that Leptospira infection can be amplified by increases in overall and relative host abundance. Evidence of shared infection among rodent host species indicates that cross-species transmission of Leptospira probably increases infection at sites with greater host richness. Additionally, evidence that rodent co-occurrence and abundance and Leptospira infection load parallel abandonment suggests that counter-urbanization can elevate zoonotic disease risk within cities, particularly in underserved communities that are burdened with disproportionate concentrations of derelict properties.
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Affiliation(s)
- Anna C Peterson
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA
| | - Bruno M Ghersi
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA
| | - Claudia Riegel
- City of New Orleans Mosquito, Termite, Rodent Control Board, New Orleans, LA, USA
| | - Elsio A Wunder
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.,Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Brazilian Ministry of Health, Salvador, Brazil
| | - James E Childs
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Michael J Blum
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA
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Erkenswick GA, Watsa M, Gozalo AS, Dudaie S, Bailey L, Muranda KS, Kuziez A, Parker PG. A multiyear survey of helminths from wild saddleback (Leontocebus weddelli) and emperor (Saguinus imperator) tamarins. Am J Primatol 2019; 81:e23063. [PMID: 31692027 PMCID: PMC7029814 DOI: 10.1002/ajp.23063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 09/10/2019] [Accepted: 09/20/2019] [Indexed: 11/08/2022]
Abstract
The establishment of baseline data on parasites from wild primates is essential to understand how changes in habitat or climatic disturbances will impact parasite-host relationships. In nature, multiparasitic infections of primates usually fluctuate temporally and seasonally, implying that the acquisition of reliable data must occur over time. Individual parasite infection data from two wild populations of New World primates, the saddleback (Leontocebus weddelli) and emperor (Saguinus imperator) tamarin, were collected over 3 years to establish baseline levels of helminth prevalence and parasite species richness (PSR). Secondarily, we explored variation in parasite prevalence across age and sex classes, test nonrandom associations of parasite co-occurrence, and assess the relationship between group size and PSR. From 288 fecal samples across 105 individuals (71 saddleback and 34 emperor tamarins), 10 parasite taxa were identified by light microscopy following centrifugation and ethyl-acetate sedimentation. Of these taxa, none were host-specific, Dicrocoeliidae and Cestoda prevalences differed between host species, Prosthenorchis and Strongylida were the most prevalent. Host age was positively associated with Prosthenorchis ova and filariform larva, but negatively with cestode and the Rhabditoidea ova. We detected no differences between expected and observed levels of co-infection, nor between group size and parasite species richness over 30 group-years. Logistic models of individual infection status did not identify a sex bias; however, age and species predicted the presence of four and three parasite taxa, respectively, with saddleback tamarins exhibiting higher PSR. Now that we have reliable baseline data for future monitoring of these populations, next steps involve the molecular characterization of these parasites, and exploration of linkages with health parameters.
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Affiliation(s)
- Gideon A. Erkenswick
- Department of Biology, University of Missouri-St. Louis,
One University Blvd., Saint Louis, MO 63121, USA
- Field Projects International, 7331 Murdoch Ave, Saint
Louis, MO 63119, USA
| | - Mrinalini Watsa
- Department of Biology, University of Missouri-St. Louis,
One University Blvd., Saint Louis, MO 63121, USA
- Field Projects International, 7331 Murdoch Ave, Saint
Louis, MO 63119, USA
| | - Alfonso S. Gozalo
- Comparative Medicine Branch, National Institute of Allergy
and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892,
USA
| | - Shay Dudaie
- Department of Biology, University of Missouri-St. Louis,
One University Blvd., Saint Louis, MO 63121, USA
| | - Lindsey Bailey
- Department of Biology, University of Missouri-St. Louis,
One University Blvd., Saint Louis, MO 63121, USA
| | - Kudakwashe S. Muranda
- Department of Biology, University of Missouri-St. Louis,
One University Blvd., Saint Louis, MO 63121, USA
| | - Alaa Kuziez
- Department of Biology, University of Missouri-St. Louis,
One University Blvd., Saint Louis, MO 63121, USA
| | - Patricia G. Parker
- Department of Biology, University of Missouri-St. Louis,
One University Blvd., Saint Louis, MO 63121, USA
- WildCare Institute, Saint Louis Zoo, One Government Dr.,
Saint Louis, MO 63110, USA
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5
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Richman SK, Irwin RE, Bosak JT, Bronstein JL. Consequences of secondary nectar robbing for male components of plant reproduction. AMERICAN JOURNAL OF BOTANY 2018; 105:943-949. [PMID: 29797579 DOI: 10.1002/ajb2.1082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 02/09/2018] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY Organisms engage in multiple species interactions simultaneously. While pollination studies generally focus on plants and pollinators exclusively, secondary robbing, a behavior that requires other species (primary robbers) to first create access holes in corollas, is common. It has been shown that secondary robbing can reduce plants' female fitness; however, we lack knowledge about its impact on male plant fitness. METHODS We experimentally simulated primary and secondary robbing in the monocarpic perennial Ipomopsis aggregata (Polemoniaceae), quantifying indirect effects on pollinator-mediated pollen (dye) donation. We also assessed whether continual nectar removal via the floral opening has similar effects on hummingbird-pollinator behavior as continual secondary robbing through robber holes. KEY RESULTS We found no significant indirect effects of secondary robbing on a component of Ipomopsis male fitness. Although robbing did reduce pollen (dye) donation due to avoidance of robbed plants by pollinating hummingbirds, pollen donation did not differ between the two robbing treatments. The effects of secondary robbing on hummingbird behavior resembled effects of chronic nectar removal by pollinators. Our results indicate that hummingbird pollinators may use a combination of cues, including cues given by the presence or absence of nectar, to make foraging decisions. CONCLUSIONS Combined with prior research, this study suggests that secondary robbing is less costly to a component of male fitness than to female fitness in Ipomopsis, broadening our knowledge of the overall costs of mutualism exploitation to total plant fitness.
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Affiliation(s)
- Sarah K Richman
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721, USA
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado, 81224, USA
| | - Rebecca E Irwin
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado, 81224, USA
- Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, 27695, USA
| | - John T Bosak
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721, USA
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado, 81224, USA
| | - Judith L Bronstein
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721, USA
- Rocky Mountain Biological Laboratory, Crested Butte, Colorado, 81224, USA
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Tieleman BI. Understanding immune function as a pace of life trait requires environmental context. Behav Ecol Sociobiol 2018; 72:55. [PMID: 29563662 PMCID: PMC5843675 DOI: 10.1007/s00265-018-2464-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 11/09/2017] [Accepted: 02/07/2018] [Indexed: 02/07/2023]
Abstract
This article provides a brief historical perspective on the integration of physiology into the concept of the pace of life of birds, evaluates the fit of immune function into this framework, and asks what it will take to fruitfully understand immune functioning of birds in pace of life studies in the future. In the late 1970s, physiology started to seriously enter avian life history ecology, with energy as the main currency of interest, inspired by David Lack's work in the preceding decades emphasizing how food availability explained life history variation. In an effort to understand the trade-off between survival and reproduction, and specifically the mortality costs associated with hard work, in the 1980s and 1990s, other physiological phenomena entered the realm of animal ecologists, including endocrinology, oxidative stress, and immunology. Reviewing studies thus far to evaluate the role of immune function in a life history context and particularly to address the questions whether immune function (1) consistently varies with life history variation among free-living bird species and (2) mediates life history trade-offs in experiments with free-living bird species; I conclude that, unlike energy metabolism, the immune system does not closely covary with life history among species nor mediates the classical trade-offs within individuals. Instead, I propose that understanding the tremendous immunological variation uncovered among free-living birds over the past 25 years requires a paradigm shift. The paradigm should shift from viewing immune function as a costly trait involved in life history trade-offs to explicitly including the benefits of the immune system and placing it firmly in an environmental and ecological context. A first step forward will be to quantify the immunobiotic pressures presented by diverse environmental circumstances that both shape and challenge the immune system of free-living animals. Current developments in the fields of infectious wildlife diseases and host-microbe interactions provide promising steps in this direction.
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Affiliation(s)
- B. Irene Tieleman
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 CC Groningen, The Netherlands
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7
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Klaus A, Zimmermann E, Röper KM, Radespiel U, Nathan S, Goossens B, Strube C. Co-infection patterns of intestinal parasites in arboreal primates (proboscis monkeys, Nasalis larvatus) in Borneo. Int J Parasitol Parasites Wildl 2017; 6:320-329. [PMID: 29988805 PMCID: PMC6031963 DOI: 10.1016/j.ijppaw.2017.09.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 08/28/2017] [Accepted: 09/14/2017] [Indexed: 12/15/2022]
Abstract
Non-human primates of South-East Asia remain under-studied concerning parasite epidemiology and co-infection patterns. Simultaneously, efforts in conservation demand knowledge of parasite abundance and biodiversity in threatened species. The Endangered proboscis monkey, Nasalis larvatus, a primate flagship species for conservation in Borneo, was investigated in the present study. Habitat loss and fragmentation are among the greatest threats to bachelor and harem groups of this folivorous colobine. Designed as a follow-up study, prevalence and co-infection status of intestinal parasites from N. larvatus in a protected area in Malaysian Borneo were analyzed from fecal samples using a flotation method. For the first time, the intestinal parasite co-infection patterns were examined using quantitative analyses. Overall, 92.3% of fecal samples (N = 652) were positive for helminth eggs. Five helminth groups were detected: (1) trichurids (82.7% prevalence) including Trichuris spp. (82.1%) and Anatrichosoma spp. (1.4%), (2) strongyles (58.9%) including Trichostrongylus spp. (48.5%) and Oesophagostomum/Ternidens spp. (22.8%), (3) Strongyloides fuelleborni (32.7%), (4) Ascaris lumbricoides (8.6%), and (5) Enterobius spp. (5.5%). On average, an individual was co-infected with two different groups. Significant positive associations were found for co-infections of trichurids with strongyles and S. fuelleborni as well as S. fuelleborni with A. lumbricoides and strongyles. This study shows a high prevalence of various gastrointestinal helminths with potential transmission pathways primarily related to soil and with zoonotic relevance in wild proboscis monkeys in their remaining natural habitats. Observed positive associations of trichurids with strongyles and Strongyloides spp. may result from the high prevalence of trichurids. Similarly, positive associations between Strongyloides and Ascaris were found, both of which typically occur predominantly in juvenile hosts. These findings should be considered when proposing conservation actions in altered habitats nearby human settlements and when managing captive populations.
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Affiliation(s)
- Annette Klaus
- Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Buenteweg 17, 30559 Hannover, Germany
- Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Buenteweg 17, 30559 Hannover, Germany
| | - Elke Zimmermann
- Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Buenteweg 17, 30559 Hannover, Germany
| | - Kathrin Monika Röper
- Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Buenteweg 17, 30559 Hannover, Germany
| | - Ute Radespiel
- Institute of Zoology, University of Veterinary Medicine Hannover, Hannover, Buenteweg 17, 30559 Hannover, Germany
| | - Senthilvel Nathan
- Sabah Wildlife Department, 5th Floor, B Block, Wisma MUIS, 88100 Kota Kinabalu, Sabah, Malaysia
| | - Benoit Goossens
- Sabah Wildlife Department, 5th Floor, B Block, Wisma MUIS, 88100 Kota Kinabalu, Sabah, Malaysia
- Organisms and Environment Division, School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, United Kingdom
- Danau Girang Field Centre, C/o Sabah Wildlife Department, Kota Kinabalu, Sabah, Malaysia
- Sustainable Places Research Institute, Cardiff University, 33 Park Pl, Cardiff CF10 3BA, United Kingdom
| | - Christina Strube
- Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Buenteweg 17, 30559 Hannover, Germany
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Nunn CL, Craft ME, Gillespie TR, Schaller M, Kappeler PM. The sociality-health-fitness nexus: synthesis, conclusions and future directions. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0115. [PMID: 25870401 DOI: 10.1098/rstb.2014.0115] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
This theme issue has highlighted the links between sociality, health and fitness in a broad range of organisms, and with approaches that include field and captive studies of animals, comparative and meta-analyses, theoretical modelling and clinical and psychological studies of humans. In this concluding chapter, we synthesize the results of these diverse studies into some of the key concepts discussed in this issue, focusing on risks of infectious disease through social contact, the effects of competition in groups on susceptibility to disease, and the integration of sociality into research on life-history trade-offs. Interestingly, the studies in this issue both support pre-existing hypotheses, and in other ways challenge those hypotheses. We focus on unexpected results, including a lack of association between ectoparasites and fitness and weak results from a meta-analysis of the links between dominance rank and immune function, and place these results in a broader context. We also review relevant topics that were not covered fully in this theme issue, including self-medication and sickness behaviours, society-level defences against infectious disease, sexual selection, evolutionary medicine, implications for conservation biology and selective pressures on parasite traits. We conclude by identifying general open questions to stimulate and guide future research on the links between sociality, health and fitness.
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Affiliation(s)
- Charles L Nunn
- Department of Evolutionary Anthropology, Duke University, Box 90383, Durham, NC 27708, USA Duke Global Health Institute, Duke University, 310 Trent Drive, Durham, NC 27710, USA
| | - Meggan E Craft
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN 55108, USA
| | - Thomas R Gillespie
- Department of Environmental Sciences and Program in Population Biology, Ecology and Evolution, Emory University, Atlanta, GA 30322, USA Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | - Mark Schaller
- Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver, British Columbia, Canada V6T1Z4
| | - Peter M Kappeler
- Behavioral Ecology and Sociobiology Unit, German Primate Center, Göttingen, Germany Department of Sociobiology/Anthropology, University of Göttingen, Göttingen, Germany
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Cohen C, Einav M, Hawlena H. Path analyses of cross-sectional and longitudinal data suggest that variability in natural communities of blood-associated parasites is derived from host characteristics and not interspecific interactions. Parasit Vectors 2015; 8:429. [PMID: 26286391 PMCID: PMC4545369 DOI: 10.1186/s13071-015-1029-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/02/2015] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The parasite composition of wild host individuals often impacts their behavior and physiology, and the transmission dynamics of pathogenic species thereby determines disease risk in natural communities. Yet, the determinants of parasite composition in natural communities are still obscure. In particular, three fundamental questions remain open: (1) what are the relative roles of host and environmental characteristics compared with direct interactions between parasites in determining the community composition of parasites? (2) do these determinants affect parasites belonging to the same guild and those belonging to different guilds in similar manners? and (3) can cross-sectional and longitudinal analyses work interchangeably in detecting community determinants? Our study was designed to answer these three questions in a natural community of rodents and their fleas, ticks, and two vector-borne bacteria. METHODS We sampled a natural population of Gerbillus andersoni rodents and their blood-associated parasites on two occasions. By combining path analysis and model selection approaches, we then explored multiple direct and indirect paths that connect (i) the environmental and host-related characteristics to the infection probability of a host by each of the four parasite species, and (ii) the infection probabilities of the four species by each other. RESULTS Our results suggest that the majority of paths shaping the blood-associated communities are indirect, mostly determined by host characteristics and not by interspecific interactions or environmental conditions. The exact effects of host characteristics on infection probability by a given parasite depend on its life history and on the method of sampling, in which the cross-sectional and longitudinal methods are complementary. CONCLUSIONS Despite the awareness of the need of ecological investigations into natural host-vector-parasite communities in light of the emergence and re-emergence of vector-borne diseases, we lack sampling methods that are both practical and reliable. Here we illustrated how comprehensive patterns can be revealed from observational data by applying path analysis and model selection approaches and combining cross-sectional and longitudinal analyses. By employing this combined approach on blood-associated parasites, we were able to distinguish between direct and indirect effects and to predict the causal relationships between host-related characteristics and the parasite composition over time and space. We concluded that direct interactions within the community play only a minor role in determining community composition relative to host characteristics and the life history of the community members.
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Affiliation(s)
- Carmit Cohen
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
| | - Monica Einav
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
| | - Hadas Hawlena
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel.
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10
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Biard C, Monceau K, Motreuil S, Moreau J. Interpreting immunological indices: The importance of taking parasite community into account. An example in blackbirds
Turdus merula. Methods Ecol Evol 2015. [DOI: 10.1111/2041-210x.12371] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Clotilde Biard
- Sorbonne Université UPMC Univ Paris 06 UPEC, Paris 7, CNRS, INRA, IRD Institut d'Écologie et des Sciences de l'Environnement de Paris F‐75005 Paris France
| | - Karine Monceau
- UMR CNRS 6282 Biogéosciences Equipe Ecologie‐Evolutive Université de Bourgogne 6 Bd Gabriel F‐21000 Dijon France
| | - Sébastien Motreuil
- UMR CNRS 6282 Biogéosciences Equipe Ecologie‐Evolutive Université de Bourgogne 6 Bd Gabriel F‐21000 Dijon France
| | - Jérôme Moreau
- UMR CNRS 6282 Biogéosciences Equipe Ecologie‐Evolutive Université de Bourgogne 6 Bd Gabriel F‐21000 Dijon France
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11
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Vaumourin E, Vourc'h G, Telfer S, Lambin X, Salih D, Seitzer U, Morand S, Charbonnel N, Vayssier-Taussat M, Gasqui P. To be or not to be associated: power study of four statistical modeling approaches to identify parasite associations in cross-sectional studies. Front Cell Infect Microbiol 2014; 4:62. [PMID: 24860791 PMCID: PMC4030204 DOI: 10.3389/fcimb.2014.00062] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 04/23/2014] [Indexed: 01/08/2023] Open
Abstract
A growing number of studies are reporting simultaneous infections by parasites in many different hosts. The detection of whether these parasites are significantly associated is important in medicine and epidemiology. Numerous approaches to detect associations are available, but only a few provide statistical tests. Furthermore, they generally test for an overall detection of association and do not identify which parasite is associated with which other one. Here, we developed a new approach, the association screening approach, to detect the overall and the detail of multi-parasite associations. We studied the power of this new approach and of three other known ones (i.e., the generalized chi-square, the network and the multinomial GLM approaches) to identify parasite associations either due to parasite interactions or to confounding factors. We applied these four approaches to detect associations within two populations of multi-infected hosts: (1) rodents infected with Bartonella sp., Babesia microti and Anaplasma phagocytophilum and (2) bovine population infected with Theileria sp. and Babesia sp. We found that the best power is obtained with the screening model and the generalized chi-square test. The differentiation between associations, which are due to confounding factors and parasite interactions was not possible. The screening approach significantly identified associations between Bartonella doshiae and B. microti, and between T. parva, T. mutans, and T. velifera. Thus, the screening approach was relevant to test the overall presence of parasite associations and identify the parasite combinations that are significantly over- or under-represented. Unraveling whether the associations are due to real biological interactions or confounding factors should be further investigated. Nevertheless, in the age of genomics and the advent of new technologies, it is a considerable asset to speed up researches focusing on the mechanisms driving interactions between parasites.
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Affiliation(s)
- Elise Vaumourin
- INRA, UR346 Epidémiologie Animale Saint Genès Champanelle, France ; INRA-Anses-ENVA, USC BIPAR Maisons-Alfort, France
| | - Gwenaël Vourc'h
- INRA, UR346 Epidémiologie Animale Saint Genès Champanelle, France
| | - Sandra Telfer
- School of Biological Sciences, University of Aberdeen Aberdeen, UK
| | - Xavier Lambin
- School of Biological Sciences, University of Aberdeen Aberdeen, UK
| | - Diaeldin Salih
- Department of Ticks and Tick-borne Diseases, Veterinary Research Institute Khartoum, Sudan
| | - Ulrike Seitzer
- Division of Veterinary-Infection Biology and Immunology, Research Center Borstel Borstel, Germany
| | - Serge Morand
- Institut des Sciences de l'Evolution (CNRS /IRD / UM2), University of Montpellier 2 Montpellier, France ; Animal et Gestion Intégrée des Risques, CIRAD Montpellier, France
| | - Nathalie Charbonnel
- INRA, UMR CBGP (INRA / IRD / CIRAD / Montpellier SupAgro) Montpellier, France
| | | | - Patrick Gasqui
- INRA, UR346 Epidémiologie Animale Saint Genès Champanelle, France
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