scholarly journals Ecological niche modeling of Babesia sp infection in wildlife experimentally evaluated in questing Ixodes ricinus.

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Stefania Zanet ◽  
Ezio Ferroglio ◽  
Elena Battisti ◽  
Paolo Tizzani
Keyword(s):  
Ecological Niche Modeling ◽  
Roe Deer ◽  
Infection Prevalence ◽  
Tick Abundance ◽  
Preventive Actions ◽  
Presence Data ◽  
Alpine Chamois ◽  
Suitable Area ◽  
Reservoir Hosts ◽  
Babesia Spp

Tick-borne diseases and especially protozoa of the genus Babesia, are gaining increasing attention as emerging zoonotic pathogens. Zoonotic species like B. venatorum and B. microti have wild animals as main reservoir hosts. We propose a habitat suitability model for Babesia spp., as tool for institutions and policy makes to better understand the entity of Babesia presence, to improve diagnostic awareness and to optimize screening and preventive actions. The probability of presence of Babesia spp. was estimated using as presence data, wild ruminants positive by PCR to Babesia spp. which were correlated to environmental factors that can favor or limit vector and host availability. We developed three separate models to discriminate the different roles of Red deer and Roe deer and Alpine chamois in Babesia spp. epidemiology. A comprehensive model using all presence data from all ungulates species  was also developed. The overall suitable area for Babesia spp. in this simulation is of 3723 km2, which correspond to 15.51% of the background regional territory. The model developed was empirically validated assessing tick abundance in randomly chosen areas classified by the model as moderately or highly suitable for Babesia spp. Collected ticks were tested by PCR for Babesia spp. to confirm model predictions as infection prevalence with Babesia spp. was significantly higher in areas predicted as highly suitable compared to those classified by the model as moderately suitable for Babesia spp.  (X2=5.05 p<0.05, Odds Ratio OR= 2.12 CI95% 1.1-4.1).

scholarly journals Past, present and future suitable areas for the relict tree Pterocarya fraxinifolia (Juglandaceae): Integrating fossil records, niche modeling, and phylogeography for conservation

2021 ◽  
Author(s):  
Yi-Gang Song ◽  
Łukasz Walas ◽  
Marcin Pietras ◽  
Hoàng Văn Sâm ◽  
Hamed Yousefzadeh ◽  
...  
Keyword(s):  
Ecological Niche Modeling ◽  
Vital Role ◽  
Niche Modeling ◽  
Limiting Factors ◽  
Future Climate Change ◽  
Integrated Analysis ◽  
Land Utilization ◽  
Distribution Form ◽  
Southern Caucasus ◽  
Suitable Area

AbstractPterocarya fraxinifolia, native to the southern Caucasus and adjacent areas, has been widely introduced in Europe. In this study, we investigate the following: (1) How did its current distribution form? (2) What are the past, current, and future suitable habitats of P. fraxinifolia? (3) What is the best conservation approach? Ecological niche modeling was applied to determine its climatic demands and project the distribution of climatically suitable areas during three periods of past, current, and future (2070) time. Then, an integrated analysis of fossil data was performed. Massive expansion of Pterocarya species between the Miocene and Pliocene facilitated the arrival of P. fraxinifolia to the southern Caucasus. The Last Glacial Maximum played a vital role in its current fragmented spatial distribution in the Euxinian and Hyrcanian regions with lower elevations, and Caucasian and Irano-Turanian regions with higher elevations. Climatic limiting factors were very different across these four regions. Future climate change will create conditions for the expansion of this species in Europe. Human activities significantly decreased the suitable area for P. fraxinifolia, especially in the Euxinian, Hyrcanian, and Irano-Turanian regions. Considering genetic diversity, climate vulnerability, and land utilization, the Euxinian, Hyrcanian, and Irano-Turanian regions have been recognized as conservation priority areas for P. fraxinifolia.

scholarly journals Spatial and temporal patterns of the emerging tick-borne pathogen Borrelia miyamotoi in blacklegged ticks (Ixodes scapularis) in New York

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
F. Keesing ◽  
D. J. McHenry ◽  
M. H. Hersh ◽  
R. S. Ostfeld
Keyword(s):  
New York ◽  
Ixodes Scapularis ◽  
Quantitative Polymerase Chain Reaction ◽  
Human Infection ◽  
Ixodid Ticks ◽  
Transovarial Transmission ◽  
Infection Prevalence ◽  
Borrelia Miyamotoi ◽  
Spatial And Temporal Patterns ◽  
Reservoir Hosts

AbstractBorrelia miyamotoi, a bacterium that causes relapsing fever, is found in ixodid ticks throughout the northern hemisphere. The first cases of human infection with B. miyamotoi were identified in 2011. In the eastern USA, blacklegged ticks (Ixodes scapularis) become infected by feeding on an infected vertebrate host, or through transovarial transmission. We surveyed B. miyamotoi prevalence in ticks within forested habitats in Dutchess County, New York, and identified possible reservoir hosts. To assess spatial variation in infection, we collected questing nymphal ticks at > 150 sites. To assess temporal variation in infection, we collected questing nymphs for 8 years at a single study site. We collected questing larval ticks from nine plots to estimate the amount of transovarial transmission. To evaluate potential reservoir hosts, we captured 14 species of mammal and bird hosts naturally infested with larval blacklegged ticks and held these hosts in the laboratory until ticks fed to repletion and molted to nymphs. We determined infection for all ticks using quantitative polymerase chain reaction. The overall infection prevalence of questing nymphal ticks across all sites was ~ 1%, but prevalence at individual sites was as high as 9.1%. We detected no significant increase in infection through time. Only 0.4% of questing larval ticks were infected. Ticks having fed as larvae from short-tailed shrews, red squirrels, and opossums tended to have higher infection prevalence than did ticks having fed on other hosts. Further studies of the role of hosts in transmission are warranted. The locally high prevalence of B. miyamotoi in the New York/New England landscape suggests the importance of vigilance by health practitioners and the public.

scholarly journals Ecological Factors Characterizing the Prevalence of Bacterial Tick-Borne Pathogens in Ixodes ricinus Ticks in Pastures and Woodlands

2010 ◽  
Vol 76 (13) ◽  
pp. 4413-4420 ◽  
Author(s):  
Lénaïg Halos ◽  
Séverine Bord ◽  
Violaine Cotté ◽  
Patrick Gasqui ◽  
David Abrial ◽  
...  
Keyword(s):  
Forest Fragmentation ◽  
Ixodes Ricinus ◽  
Spotted Fever ◽  
Ecological Factors ◽  
Adult Tick ◽  
Reservoir Host ◽  
Host Community ◽  
Infection Prevalence ◽  
Spotted Fever Group ◽  
Reservoir Hosts

ABSTRACT Ecological changes are recognized as an important driver behind the emergence of infectious diseases. The prevalence of infection in ticks depends upon ecological factors that are rarely taken into account simultaneously. Our objective was to investigate the influences of forest fragmentation, vegetation, adult tick hosts, and habitat on the infection prevalence of three tick-borne bacteria, Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, and Rickettsia sp. of the spotted fever group, in questing Ixodes ricinus ticks, taking into account tick characteristics. Samples of questing nymphs and adults were taken from 61 pastures and neighboring woodlands in central France. The ticks were tested by PCR of pools of nymphs and individual adults. The individual infection prevalence was modeled using multivariate regression. The highest infection prevalences were found in adult females collected in woodland sites for B. burgdorferi sensu lato and A. phagocytophilum (16.1% and 10.7%, respectively) and in pasture sites for Rickettsia sp. (8.7%). The infection prevalence in nymphs was lower than 6%. B. burgdorferi sensu lato was more prevalent in woodlands than in pastures. Forest fragmentation favored B. burgdorferi sensu lato and A. phagocytophilum prevalence in woodlands, and in pastures, the B. burgdorferi sensu lato prevalence was favored by shrubby vegetation. Both results are probably because large amounts of edges or shrubs increase the abundance of small vertebrates as reservoir hosts. The Rickettsia sp. prevalence was maximal on pasture with medium forest fragmentation. Female ticks were more infected by B. burgdorferi sensu lato than males and nymphs in woodland sites, which suggests an interaction between the ticks and the bacteria. This study confirms the complexity of the tick-borne pathogen ecology. The findings support the importance of small vertebrates as reservoir hosts and make a case for further studies in Europe on the link between the composition of the reservoir host community and the infection prevalence in ticks.

The influence of landscape and environmental factors on ranavirus epidemiology in amphibian assemblages

2017 ◽  
Author(s):  
Brian J. Tornabene ◽  
Andrew R. Blaustein ◽  
Cheryl J. Briggs ◽  
Dana M. Calhoun ◽  
Pieter T. J. Johnson ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Host Species ◽  
Dilution Effect ◽  
Variance Partitioning ◽  
Lower Probability ◽  
Infection Prevalence ◽  
Taxonomic Richness ◽  
Amphibian Disease ◽  
Competing Models ◽  
Reservoir Hosts

ABSTRACTAimTo quantify the influence of a suite of landscape, abiotic, biotic, and host-level variables on ranavirus disease dynamics in amphibian assemblages at two biological levels (site and host-level).LocationWetlands within the East Bay region of California, USA.MethodsWe used competing models, multimodel inference, and variance partitioning to examine the influence of 16 landscape and environmental factors on patterns in site-level ranavirus presence and host-level ranavirus infection in 76 wetlands and 1,377 amphibian hosts representing five species.ResultsThe landscape factor explained more variation than any other factors in site-level ranavirus presence, but biotic and host-level factors explained more variation in host-level ranavirus infection. At both the site- and host-level, the probability of ranavirus presence correlated negatively with distance to nearest ranavirus-positive wetland. At the site-level, ranavirus presence was associated positively with taxonomic richness. However, infection prevalence within the amphibian population correlated negatively with vertebrate richness. Finally, amphibian host species differed in their likelihood of ranavirus infection: American Bullfrogs had the weakest association with infection while Western Toads had the strongest. After accounting for host species effects, hosts with greater snout-vent length had a lower probability of infection.Main conclusionsStrong spatial influences at both biological levels suggest that mobile taxa (e.g., adult amphibians, birds, reptiles) may facilitate the movement of ranavirus among hosts and across the landscape. Higher taxonomic richness at sites may provide more opportunities for colonization or the presence of reservoir hosts that may influence ranavirus presence. Higher host richness correlating with higher ranavirus infection is suggestive of a dilution effect that has been observed for other amphibian disease systems and warrants further investigation. Our study demonstrates that an array of landscape, environmental, and host-level factors were associated with ranavirus epidemiology and illustrates that their importance vary with biological level.

scholarly journals Cryptosporidium infections in terrestrial ungulates with focus on livestock: a systematic review and meta-analysis

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Kareem Hatam-Nahavandi ◽  
Ehsan Ahmadpour ◽  
David Carmena ◽  
Adel Spotin ◽  
Berit Bangoura ◽  
...  
Keyword(s):  
Systematic Review ◽  
Roe Deer ◽  
Meta Analysis ◽  
Gastrointestinal Diseases ◽  
Molecular Data ◽  
Control Measures ◽  
Infection Prevalence ◽  
Systematic Analysis ◽  
Potential Reservoir ◽  
Environment Control

Abstract Background Cryptosporidium spp. are causative agents of gastrointestinal diseases in a wide variety of vertebrate hosts. Mortality resulting from the disease is low in livestock, although severe cryptosporidiosis has been associated with fatality in young animals. Methods The goal of this systematic review and meta-analysis was to review the prevalence and molecular data on Cryptosporidium infections in selected terrestrial domestic and wild ungulates of the families Bovidae (bison, buffalo, cattle, goat, impala, mouflon sheep, sheep, yak), Cervidae (red deer, roe deer, white-tailed deer), Camelidae (alpaca, camel), Suidae (boar, pig), Giraffidae (giraffes) and Equidae (horses). Data collection was carried out using PubMed, Scopus, Science Direct and Cochran databases, with 429 papers being included in this systematic analysis. Results The results show that overall 18.9% of ungulates from the investigated species were infected with Cryptosporidium spp. Considering livestock species (cattle, sheep, goats, pigs, horses and buffaloes), analysis revealed higher Cryptosporidium infection prevalence in ungulates of the Cetartiodactyla than in those of the Perissodactyla, with cattle (29%) being the most commonly infected farm animal. Conclusions Overall, the investigated domestic ungulates are considered potential sources of Cryptosporidium contamination in the environment. Control measures should be developed to reduce the occurrence of Cryptosporidium infection in these animals. Furthermore, literature on wild populations of the named ungulate species revealed a widespread presence and potential reservoir function of wildlife.

scholarly journals Natural Lyme disease cycles maintained via sheep by co-feeding ticks

Parasitology ◽  
1997 ◽  
Vol 115 (6) ◽  
pp. 591-599 ◽  
Author(s):  
N. H. OGDEN ◽  
P. A. NUTTALL ◽  
S. E. RANDOLPH
Keyword(s):  
Lyme Disease ◽  
Experimental Evidence ◽  
Infection Prevalence ◽  
Female Tick ◽  
Experimental Transmission ◽  
Tick Abundance ◽  
Virtual Absence ◽  
Questing Ticks ◽  
Transmission Studies ◽  
Systemic Infections

We present observational and experimental evidence that cycles of the Lyme disease spirochaete, Borrelia burgdorferi s.l., can be maintained by sheep in the virtual absence of alternative hosts. A 2-year field study in upland moorland habitats of northwest UK established that sheep feed up to 80% of larval, >99% of nymphal and all of the adult female tick (Ixodes ricinus) population. Infection prevalence of B. burgdorferi in questing ticks reaches over 20%, but amplification of infection occurs principally as nymphs (20- to 30-fold), rather than larvae (4- to 7-fold), feed on sheep, and transmission from sheep to ticks occurred only during peak tick abundance in May and September. Experimental transmission studies confirmed that sheep, previously exposed to infected ticks on the moorland site, do not support systemic infections of B. burgdorferi, but they can transmit localized infections from infected to uninfected ticks co-feeding at the same site on the sheep's body.

ANTIBODY PREVALENCE AND MOLECULAR IDENTIFICATION OF BABESIA SPP. IN ROE DEER IN FRANCE

2012 ◽  
Vol 48 (2) ◽  
pp. 416-424 ◽  
Author(s):  
Suzanne Bastian ◽  
Maggy Jouglin ◽  
Nadine Brisseau ◽  
Laurence Malandrin ◽  
Geraldine Klegou ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Roe Deer ◽  
Antibody Prevalence ◽  
Babesia Spp

scholarly journals Babesia spp. Identified by PCR in Ticks Collected from Domestic and Wild Ruminants in Southern Switzerland

2006 ◽  
Vol 72 (10) ◽  
pp. 6503-6507 ◽  
Author(s):  
Heidi Hilpertshauser ◽  
Peter Deplazes ◽  
Manuela Schnyder ◽  
Lise Gern ◽  
Alexander Mathis
Keyword(s):  
Roe Deer ◽  
Babesia Bigemina ◽  
Wild Ruminants ◽  
Babesia Divergens ◽  
Cast Doubt ◽  
Concurrent Infections ◽  
Vector Borne ◽  
Tick Vectors ◽  
Reservoir Hosts

ABSTRACT Concurrent infections with vector-borne pathogens affected a cattle herd in Switzerland, and one of the pathogens was identified as Babesia bigemina, which had never been observed in this country before. Therefore, a survey of the occurrence of ruminant Babesia spp. and their tick vectors in Switzerland was conducted. A total of 2,017 ticks were collected from sheep, goats, cattle, and wild ruminants (deer, roe deer, and chamois) in southern parts of Switzerland and identified morphologically. The vast majority of the ticks (99.2%) were Ixodes ricinus, but 14 ticks from sheep and goats were identified as Dermacentor marginatus and two ticks from wild ruminants were identified as Hemaphysalis punctata. PCR analyses of 700 ticks revealed the presence of Babesia divergens (n = 6), Babesia sp. genotype EU1 (n = 14), and B. major (n = 2), whose suggested occurrence was confirmed in this study by molecular analysis, and the presence of novel Babesia sp. genotype CH1 (n = 4), which is closely related to B. odocoilei and to Babesia sp. genotype RD61 reported from North America. The identification of B. divergens and B. major in ticks collected from wild ruminants cast doubt on the postulated strict host specificity of these bovine Babesia species. Furthermore, the zoonotic Babesia sp. genotype EU1 was detected in ticks collected from domestic animals but was obtained predominantly from ticks collected from wild ruminants. More than one tick containing DNA of different Babesia spp. were collected from two red deer. Hence, the role of these game animals as reservoir hosts of Babesia spp. seems to be important but requires further investigation.

scholarly journals Environmental determinants ofIxodes ricinusticks and the incidence ofBorrelia burgdorferisensu lato, the agent of Lyme borreliosis, in Scotland

Parasitology ◽  
2012 ◽  
Vol 140 (2) ◽  
pp. 237-246 ◽  
Author(s):  
M. C. JAMES ◽  
A. S. BOWMAN ◽  
K. J. FORBES ◽  
F. LEWIS ◽  
J. E. MCLEOD ◽  
...  
Keyword(s):  
Lyme Borreliosis ◽  
Large Scale ◽  
Environmental Changes ◽  
Geographical Information ◽  
Ground Vegetation ◽  
Infection Prevalence ◽  
Tick Abundance ◽  
Pathogen Prevalence ◽  
Risk Of Exposure ◽  
Large Scale Survey

SUMMARYLyme borreliosis (LB) is the most common arthropod-borne disease of humans in the Northern hemisphere. In Europe, the causative agent,Borrelia burgdorferisensu lato complex, is principally vectored byIxodes ricinusticks. The aim of this study was to identify environmental factors influencing questingI. ricinusnymph abundance andB. burgdorferis.l. infection in questing nymphs using a large-scale survey across Scotland. Ticks, host dung and vegetation were surveyed at 25 woodland sites, and climatic variables from a Geographical Information System (GIS) were extracted for each site. A total of 2397 10 m2transect surveys were conducted and 13 250I. ricinusnymphs counted. Questing nymphs were assayed forB. burgdorferis.l. and the average infection prevalence was 5·6% (range 0·8–13·9%). More questing nymphs and higher incidence ofB. burgdorferis.l. infection were found in areas with higher deer abundance and in mixed/deciduous compared to coniferous forests, as well as weaker correlations with season, altitude, rainfall and ground vegetation. No correlation was found between nymph abundance and infection prevalence within the ranges encountered. An understanding of the environmental conditions associated with tick abundance and pathogen prevalence may be used to reduce risk of exposure and to predict future pathogen prevalence and distributions under environmental changes.

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