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Sidhoum NR, Boucheikhchoukh M, Mechouk N, Deak G. An overview of fleas (Siphonaptera) in wild and domestic mammals from Algeria with new data from the central north and south of the country. Acta Trop 2023; 247:107004. [PMID: 37619901 DOI: 10.1016/j.actatropica.2023.107004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/14/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
Fleas (Siphonaptera) are medically and veterinary important ectoparasites known to infest a wide range of host species. This study presents a systematic review complemented by new data on the diversity of flea species and host associations in Algeria. 198 mammals were examined, including previously understudied hosts such as sheep, red foxes, fennec foxes, and golden African wolves. Of these animals, 108 (54.55%) were infested with fleas. Overall, 1.906 fleas belonging to seven species (Archaeopsylla erinacei s.l., Ctenocephalides felis, C. canis, Nosopsyllus fasciatus, Pariodontis riggenbachi, Pulex irritans, Xenopsylla cheopis) were identified, originating from seven provinces across Algeria. Statistical analysis techniques were employed to process the data, including descriptive statistics, statistical tests, and principal component analysis (PCA). This study reveals the diverse flea fauna in Algeria and their association with various host species, including wild and domestic animals. This comprehensive survey aimed to combine literature reviews, fieldwork, and statistical analysis to understand fleas' diversity and host associations. The findings contribute to the growing knowledge of flea ecology and host-parasite interactions, with implications for public health and veterinary practices in Algeria and potentially other regions with similar ecological characteristics.
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Affiliation(s)
- Noureddine Rabah Sidhoum
- Biodiversity and Ecosystems Pollution Laboratory, Faculty of Life and Nature Sciences, Chadli Bendjedid University, El Tarf 36000, Algeria; Department of Veterinary Sciences, Chadli Bendjedid University, El Tarf 36000, Algeria.
| | - Mehdi Boucheikhchoukh
- Biodiversity and Ecosystems Pollution Laboratory, Faculty of Life and Nature Sciences, Chadli Bendjedid University, El Tarf 36000, Algeria; Department of Veterinary Sciences, Chadli Bendjedid University, El Tarf 36000, Algeria.
| | - Noureddine Mechouk
- Ecology of Terrestrial and Aquatics Systems Laboratory (EcoSTAq), Department of Biology, Faculty of Science, Badji Mokhtar University, Annaba 23200, Algeria; Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Calea Mănăștur 3-5, Cluj-Napoca 400372, Romania
| | - Georgiana Deak
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Calea Mănăștur 3-5, Cluj-Napoca 400372, Romania.
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Ming M, Yuan S, Fu H, Li X, Zhang H, Liu T, Bu F, Wu X. Influence of biotic and abiotic factors on flea species population dynamics on Lasiopodomys brandtii. Int J Parasitol Parasites Wildl 2023; 21:185-191. [PMID: 37575662 PMCID: PMC10422677 DOI: 10.1016/j.ijppaw.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/18/2023] [Accepted: 05/29/2023] [Indexed: 08/15/2023]
Abstract
Brandt's Vole (Lasiopodomys brandtii) is one of the most abundant rodent species in the grasslands of Inner Mongolia, China, and one of the main carriers of Yersinia pestis, the plague bacterium. There have been several instances of plague transmission among L. brandtii, and all of their dominant flea species are known carriers of plague. Little work has been done to understand the regulation of flea abundance on L. brandtii by biotic and abiotic factors. Here, we examine the impacts of host and climate variation on flea abundance on L. brandtii in May, July, and September of 2021 in the East Ujumqin Banner, Xilinhot City, Inner Mongolia Autonomous Region. We arrived at the following conclusions: 1) There were 8 flea species representing 2 families and 5 genera collected from L. brandtii, and Frontopsylla luculenta, Neopsylla pleskei orientalis, and Amphipsylla primaris mitis were most common. 2) Host body weight, host age, season, temperature, and humidity are key factors influencing flea abundance on L. brandtii. 3) Flea species vary in their respective responses to factors.
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Affiliation(s)
- Ming Ming
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University. Hohhot, China
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner Mongolia. Hohhot, China
- Key Laboratory of Grassland Resources of the Ministry of Education. Hohhot, China
| | - Shuai Yuan
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University. Hohhot, China
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner Mongolia. Hohhot, China
- Key Laboratory of Grassland Resources of the Ministry of Education. Hohhot, China
| | - Heping Fu
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University. Hohhot, China
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner Mongolia. Hohhot, China
- Key Laboratory of Grassland Resources of the Ministry of Education. Hohhot, China
| | - Xin Li
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University. Hohhot, China
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner Mongolia. Hohhot, China
- Key Laboratory of Grassland Resources of the Ministry of Education. Hohhot, China
| | - Haoting Zhang
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University. Hohhot, China
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner Mongolia. Hohhot, China
- Key Laboratory of Grassland Resources of the Ministry of Education. Hohhot, China
| | - Tao Liu
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University. Hohhot, China
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner Mongolia. Hohhot, China
- Key Laboratory of Grassland Resources of the Ministry of Education. Hohhot, China
| | - Fan Bu
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University. Hohhot, China
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner Mongolia. Hohhot, China
- Key Laboratory of Grassland Resources of the Ministry of Education. Hohhot, China
| | - Xiaodong Wu
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University. Hohhot, China
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner Mongolia. Hohhot, China
- Key Laboratory of Grassland Resources of the Ministry of Education. Hohhot, China
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3
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Krasnov BR, Spickett A, Junker K, van der Mescht L, Matthee S. Functional and phylogenetic uniqueness of helminth and flea assemblages of two South African rodents. Int J Parasitol 2021; 51:865-876. [PMID: 33848500 DOI: 10.1016/j.ijpara.2021.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/15/2021] [Accepted: 02/15/2021] [Indexed: 10/21/2022]
Abstract
The loss of a particular species from a community may have different effects on its functioning, depending on the presence or absence of functionally similar or phylogenetically close species in that community (redundancy). Redundancy is thus defined as the fraction of species diversity not expressed by functional or phylogenetic diversity. We assessed functional and phylogenetic alpha- and beta-redundancy in helminth and flea assemblages of two species of South African rodents, Rhabdomys dilectus and Rhabdomys pumilio, using community uniqueness as the inverse indicator of redundancy. We asked whether patterns of functional and phylogenetic alpha- and beta-uniqueness differed between (i) parasite groups (endo- versus ectoparasites), (ii) host species within parasite groups, and (iii) biomes within host species. We found differences between the two hosts in the functional and phylogenetic alpha-uniqueness (but not beta-uniqueness) of flea, but not helminth, assemblages. Significant correlations between the alpha-uniqueness of parasite assemblages and the total parasite prevalence were found only for phylogenetic uniqueness and only in helminths. Pairwise site-by-site dissimilarities in uniqueness (beta-uniqueness) and pairwise dissimilarity in prevalence were significantly associated (positively) in helminths but not in fleas. A between-biome difference in functional (but not phylogenetic) alpha-uniqueness was found in both helminth and flea assemblages harboured by R. pumilio. We conclude that the resilience of parasite assemblages in terms of the effect on hosts depends not only on their transmission strategy but also on traits of host species and environmental factors.
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Affiliation(s)
- Boris R Krasnov
- Mitrani Department of Desert Ecology, Swiss Institute of Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion, Israel.
| | - Andrea Spickett
- Agricultural Research Council-Onderstepoort Veterinary Institute, Onderstepoort, South Africa
| | - Kerstin Junker
- Agricultural Research Council-Onderstepoort Veterinary Institute, Onderstepoort, South Africa
| | - Luther van der Mescht
- Department of Conservation Ecology and Entomology, Stellenbosch University, Matieland, South Africa
| | - Sonja Matthee
- Department of Conservation Ecology and Entomology, Stellenbosch University, Matieland, South Africa
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Butler RA, Trout Fryxell RT, Houston AE, Bowers EK, Paulsen D, Coons LB, Kennedy ML. Small-mammal characteristics affect tick communities in southwestern Tennessee (USA). INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2020; 12:150-154. [PMID: 32547921 PMCID: PMC7284121 DOI: 10.1016/j.ijppaw.2020.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 11/25/2022]
Abstract
Life histories can influence the degree of parasite infestations on a host. Pressures exerted on hosts based on age and sex convey varying degrees of parasite prevalence due to differences in host lifestyles, but it is not known how interactions between different host traits affect tick numbers. The objective of this study was to determine if host characteristics (e.g., age, sex, weight, and their interactions) affect the mean number of ticks found on small mammals regardless of host species or habitat. Sherman live traps were placed in forest and grass/forb habitats representative of the southeastern United States. After capture, host characteristics were recorded, and hosts were then searched for ticks. A total of 281 small mammals (148 Peromyscus leucopus, 34 P. maniculatus, 76 Sigmodon hispidus, 16 Microtus pinetorum, and 7 Ochrotomys nuttalli) and 610 ticks (488 Dermacentor variabilis, 114 Ixodes scapularis, 1 Amblyomma americanum, and 7 A. maculatum) were collected in this study. Host's age, sex, and weight affected the number of ticks collected from small mammals and significant interaction effects between host traits occurred (weight by sex, weight by age, and sex by age). For instance, female subadult rodents had significantly more ticks compared to female adults, male subadults had significantly fewer ticks compared to male adults, and the number of ticks on a host increased as host body mass increased. These results support the hypothesis that the number of ticks vary on rodent hosts based on life histories and trait interactions. Therefore, understanding the behavioral mechanisms of a host can aid in the management of parasites in the environment. Host life histories predict the number of ticks present on a rodent. Male and subadult rodents are infested with an overall greater number of ticks than females and adults. Rodents have more ticks as their weight increases. Interactions between sex and age predict the number of ticks present on a rodent.
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Affiliation(s)
- R A Butler
- Department of Biological Sciences, The University of Memphis, Memphis, TN, USA.,Department of Entomology and Plant Pathology, The University of Tennessee, Knoxville, TN, USA
| | - R T Trout Fryxell
- Department of Entomology and Plant Pathology, The University of Tennessee, Knoxville, TN, USA
| | - A E Houston
- Department of Forestry, Wildlife and Fisheries, The University of Tennessee, Knoxville, TN, USA
| | - E K Bowers
- Department of Biological Sciences, The University of Memphis, Memphis, TN, USA
| | - D Paulsen
- Department of Entomology and Plant Pathology, The University of Tennessee, Knoxville, TN, USA
| | - L B Coons
- Department of Biological Sciences, The University of Memphis, Memphis, TN, USA
| | - M L Kennedy
- Department of Biological Sciences, The University of Memphis, Memphis, TN, USA
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5
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Cassin Sackett L. Does the host matter? Variable influence of host traits on parasitism rates. Int J Parasitol 2018; 48:27-39. [DOI: 10.1016/j.ijpara.2017.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 06/28/2017] [Accepted: 07/03/2017] [Indexed: 11/28/2022]
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Messika I, Garrido M, Kedem H, China V, Gavish Y, Dong Q, Fuqua C, Clay K, Hawlena H. From endosymbionts to host communities: factors determining the reproductive success of arthropod vectors. Oecologia 2017; 184:859-871. [PMID: 28721523 DOI: 10.1007/s00442-017-3906-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 06/20/2017] [Indexed: 11/26/2022]
Abstract
Elucidating the factors determining reproductive success has challenged scientists since Darwin, but the exact pathways that shape the evolution of life history traits by connecting extrinsic (e.g., landscape structure) and intrinsic (e.g., female's age and endosymbionts) factors and reproductive success have rarely been studied. Here we collected female fleas from wild rodents in plots differing in their densities and proportions of the most dominant rodent species. We then combined path analysis and model selection approaches to explore the network of effects, ranging from micro to macroscales, determining the reproductive success of these fleas. Our results suggest that female reproductive success is directly and positively associated with their infection by Mycoplasma bacteria and their own body mass, and with the rodent species size and total density. In addition, we found evidence for indirect effects of rodent sex and rodent community diversity on female reproductive success. These results highlight the importance of exploring interrelated factors across organization scales while studying the reproductive success of wild organisms, and they have implications for the control of vector-borne diseases.
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Affiliation(s)
- Irit Messika
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Mario Garrido
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990, Midreshet Ben-Gurion, Israel
| | - Hadar Kedem
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Victor China
- Department of Zoology, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
- The Inter-University Institute for Marine Sciences, Eilat, Israel
| | - Yoni Gavish
- Faculty of Biological Sciences, School of Biology, University of Leeds, Leeds, UK
| | - Qunfeng Dong
- Department of Public Health Sciences, Center for Biomedical Informatics, Stritch School of Medicine, Loyola University Chicago, Chicago, IL, USA
| | - Clay Fuqua
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - Keith Clay
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - Hadas Hawlena
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990, Midreshet Ben-Gurion, Israel.
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7
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Postawa T, Nagy Z. Variation of parasitism patterns in bats during hibernation: the effect of host species, resources, health status, and hibernation period. Parasitol Res 2016; 115:3767-78. [PMID: 27240839 PMCID: PMC5040749 DOI: 10.1007/s00436-016-5138-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/17/2016] [Indexed: 02/01/2023]
Abstract
During critical periods of food shortage or variable climatic conditions, the choice of an appropriate host can increase the survival and reproductive performance of parasites. In turn, one of the unique adaptations to periodical food shortages is hibernation, which is often found among insectivorous bat species in the temperate zone. While hibernating, bats are completely defenseless against both predators and ectoparasites, their immune and endocrine systems are diminished, and survival is dependent on the accumulated fat reserves. Differences in the health status or in the rate of consumption of the resources might also explain species-specific differences in ectoparasite abundance, especially between closely related host species, such as the greater mouse-eared bat (Myotis myotis) and the lesser mouse-eared bat (M. blythii) during hibernation. In the present study, the abundance of two ecologically distinct (summer and winter) types of ectoparasites was examined in terms of its influence on the body condition and hemoglobin content of the two host species. The effects of demographic factors, such as host sex and age, were also investigated. Despite a similar pattern of deteriorating body condition and hemoglobin concentration, M. myotis was more parasitized than was M. blythii. The marked decrease in hemoglobin content in first-year females of both host species correlated with the highest parasite load and indicated a risk of anemia. At the intraspecific level, ectoparasite abundance was not correlated with body condition (resources), but it negatively affected hemoglobin content; however, this mostly concerned M. blythii, which had a lower parasite load. Therefore, it can be concluded that interspecific differences in ectoparasite abundance may result from parasites selecting the host species that is less sensitive to their activity. In turn, in summer ectoparasites, the preference for female hosts is probably attributable to the likelihood of reinfection rather than to an effect of host resources or health status. The absence of sex-based preferences in winter ectoparasites could be explained by equal host availability.
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Affiliation(s)
- Tomasz Postawa
- Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Sławkowska 17, 31-016, Kraków, Poland.
| | - Zoltan Nagy
- Foundation for School, Densusianu Str. 6/A, 400428, Cluj-Napoca, Romania
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Young HS, Dirzo R, McCauley DJ, Agwanda B, Cattaneo L, Dittmar K, Eckerlin RP, Fleischer RC, Helgen LE, Hintz A, Montinieri J, Zhao S, Helgen KM. Drivers of Intensity and Prevalence of Flea Parasitism on Small Mammals in East African Savanna Ecosystems. J Parasitol 2015; 101:327-35. [PMID: 25634599 DOI: 10.1645/14-684.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The relative importance of environmental factors and host factors in explaining variation in prevalence and intensity of flea parasitism in small mammal communities is poorly established. We examined these relationships in an East African savanna landscape, considering multiple host levels: across individuals within a local population, across populations within species, and across species within a landscape. We sampled fleas from 2,672 small mammals of 27 species. This included a total of 8,283 fleas, with 5 genera and 12 species identified. Across individual hosts within a site, both rodent body mass and season affected total intensity of flea infestation, although the explanatory power of these factors was generally modest (<10%). Across host populations in the landscape, we found consistently positive effects of host density and negative effects of vegetation cover on the intensity of flea infestation. Other factors explored (host diversity, annual rainfall, anthropogenic disturbance, and soil properties) tended to have lower and less consistent explanatory power. Across host species in the landscape, we found that host body mass was strongly positively correlated with both prevalence and intensity of flea parasitism, while average robustness of a host species to disturbance was not correlated with flea parasitism. Cumulatively, these results provide insight into the intricate roles of both host and environmental factors in explaining complex patterns of flea parasitism across landscape mosaics.
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Affiliation(s)
- Hillary S Young
- Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California 93106
| | | | - Douglas J McCauley
- Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California 93106
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Postawa T, Furman A. Abundance Patterns of Ectoparasites Infesting Different Populations ofMiniopterusSpecies in Their Contact Zone in Asia Minor. ACTA CHIROPTEROLOGICA 2014. [DOI: 10.3161/150811014x687341] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Sarasa M, Pérez JM, Alasaad S, Serrano E, Soriguer RC, Granados JE, Fandos P, Joachim J, Gonzalez G. Neatness depends on season, age, and sex in Iberian ibex Capra pyrenaica. Behav Ecol 2011. [DOI: 10.1093/beheco/arr092] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Khokhlova IS, Serobyan V, Degen AA, Krasnov BR. Discrimination of host sex by a haematophagous ectoparasite. Anim Behav 2011. [DOI: 10.1016/j.anbehav.2010.10.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
We recovered larval trombiculid mites (i.e. chiggers), vectors of scrub typhus, from small mammal hosts in Taiwan, and compared the relative degree of engorgement (RDE) of the dominant chigger (Leptotrombidium imphalum) from different hosts. Naturally occurring chiggers recovered from Rattus losea and Bandicota indica were 1·4x and 1·3x as engorged as those from Apodemus agrarius. Within each host species, RDE was negatively related to chigger loads, but was mostly unrelated to gender or to body or reproductive condition of hosts. We documented significant variation in chigger engorgement both within and among host species; to the extent that RDE is a proxy for fitness, this contradicts predictions of the Ideal Free Distribution (IFD) that the per capita fitness of vectors should be similar among hosts. Failure to meet predictions of the IFD may reflect the limited mobility of chiggers, which consequently must be less selective in the hosts on which they feed. Further disease control efforts should consider vector feeding success in addition to vector abundance and may be able to capitalize on the unsuitability of certain hosts in supporting disease vectors.
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Gürtler RE, Ceballos LA, Ordóñez-Krasnowski P, Lanati LA, Stariolo R, Kitron U. Strong host-feeding preferences of the vector Triatoma infestans modified by vector density: implications for the epidemiology of Chagas disease. PLoS Negl Trop Dis 2009; 3:e447. [PMID: 19478849 PMCID: PMC2682203 DOI: 10.1371/journal.pntd.0000447] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Accepted: 04/30/2009] [Indexed: 11/28/2022] Open
Abstract
Background Understanding the factors that affect the host-feeding preferences of triatomine bugs is crucial for estimating transmission risks and predicting the effects of control tactics targeting domestic animals. We tested whether Triatoma infestans bugs prefer to feed on dogs vs. chickens and on dogs vs. cats and whether vector density modified host choices and other vital rates under natural conditions. Methodology Two host choice experiments were conducted in small caged huts with two rooms between which bugs could move freely. Matched pairs of dog–chicken (six) and dog–cat (three) were assigned randomly to two levels of vector abundance and exposed to starved bugs during three nights. Bloodmeals from 1,160 bugs were tested by a direct enzyme-linked immunosorbent assay. Principal Findings Conditional logistic regression showed that dogs were highly preferred over chickens or cats and that vector density modified host-feeding choices. The relative risk of a bug being blood-engorged increased significantly when it fed only on dog rather than chicken or cat. Bugs achieved higher post-exposure weight at higher vector densities and successive occasions, more so if they fed on a dog rather than on a cat. Conclusions Our findings strongly refute the hypothesis that T. infestans prefers to blood-feed on chickens rather than dogs. An increase in dog or cat availability or accessibility will increase the rate of bug feeding on them and exert strong non-linear effects on R0. When combined with between-dog heterogeneities in exposure, infection, and infectiousness, the strong bug preference for dogs can be exploited to target dogs in general, and even the specific individuals that account for most of the risk, with topical lotions or insecticide-impregnated collars to turn them into baited lethal traps or use them as transmission or infestation sentinels based on their immune response to Trypanosoma cruzi or bug salivary antigens. Chagas disease is a complex zoonosis with more than 150 mammalian host species, nearly a dozen blood-sucking triatomine species as main vectors, and 9–11 million people infected with Trypanosoma cruzi (its causal agent) in the Americas. Triatoma infestans, a highly domesticated species and one of the main vectors, feeds more often on domestic animals than on humans in northern Argentina. The question of whether there are host-feeding preferences among dogs, cats, and chickens is crucial to estimating transmission risks and predicting the effects of control tactics targeting them. This article reports the first host choice experiments of triatomine bugs conducted in small huts under natural conditions. The results demonstrate that T. infestans consistently preferred dogs to chickens or cats, with host shifts occurring more frequently at higher vector densities. Combined with earlier findings showing that dogs have high infection rates, are highly infectious, and have high contact rates with humans and domestic bugs, our results reinforce the role of dogs as the key reservoirs of T. cruzi. The strong bug preference for dogs can be exploited to target dogs with topical lotions or insecticide-impregnated collars to turn them into baited lethal traps or use them as transmission or infestation sentinels.
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Affiliation(s)
- Ricardo E Gürtler
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina.
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Sex ratio in flea infrapopulations: number of fleas, host gender and host age do not have an effect. Parasitology 2008; 135:1133-41. [PMID: 18561869 DOI: 10.1017/s0031182008004551] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This study set out to determine whether the sex ratio of fleas collected from host bodies is a reliable indicator of sex ratio in the entire flea population. To answer this question, previously published data on 18 flea species was used and it was tested to see whether a correlation exists between the sex ratio of fleas collected from host bodies and the sex ratio of fleas collected from host burrows. Across species, the female:male ratio of fleas on hosts correlated strongly with the female:male ratio of fleas in their burrows, with the slope of the regression overlapping 1. Controlling for flea phylogeny by independent contrasts produced similar results. It was also ascertained whether a host individual is a proportional random sampler of male and female fleas and whether the sex ratio in flea infrapopulations depends on the size of infrapopulations and on the gender and age of a host. Using field data, the sex ratio in infrapopulations of 7 flea species parasitic on 4 rodent species was analysed. Populations of 3 species (Nosopsyllus iranus, Parapulex chephrenis and Xenopsylla conformis) were significantly female-biased, whereas male bias was found in 1 species (Synosternus cleopatrae). In general, the sex ratio of fleas collected from an individual rodent did not differ significantly from the sex ratio in the entire flea population. Neither host gender, and age nor number of fleas co-occurring on a host affected (a) the sex ratio in flea infrapopulations and (b) the probability of an infrapopulation to be either female- or male-biased.
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