scholarly journals Linking Zoonosis Emergence to Farmland Invasion by Fluctuating Herbivores: Common Vole Populations and Tularemia Outbreaks in NW Spain

2021 ◽  
Vol 8 ◽  
Author(s):  
Silvia Herrero-Cófreces ◽  
François Mougeot ◽  
Xavier Lambin ◽  
Juan José Luque-Larena
Keyword(s):  
Disease Transmission ◽  
Common Vole ◽  
Future Research ◽  
Nw Spain ◽  
Rodent Host ◽  
Host Group ◽  
Muroid Rodents ◽  
Cyclic Variations ◽  
Common Voles ◽  
Fluctuating Populations

The expansion and intensification of agriculture are driving profound changes in ecosystems worldwide, favoring the (re)emergence of many human infectious diseases. Muroid rodents are a key host group for zoonotic infectious pathogens and frequently invade farming environments, promoting disease transmission and spillover. Understanding the role that fluctuating populations of farm dwelling rodents play in the epidemiology of zoonotic diseases is paramount to improve prevention schemes. Here, we review a decade of research on the colonization of farming environments in NW Spain by common voles (Microtus arvalis) and its public health impacts, specifically periodic tularemia outbreaks in humans. The spread of this colonizing rodent was analogous to an invasion process and was putatively triggered by the transformation and irrigation of agricultural habitats that created a novel terrestrial-aquatic interface. This irruptive rodent host is an effective amplifier for the Francisella tularensis bacterium during population outbreaks, and human tularemia episodes are tightly linked in time and space to periodic (cyclic) variations in vole abundance. Beyond the information accumulated to date, several key knowledge gaps about this pathogen-rodent epidemiological link remain unaddressed, namely (i) did colonizing vole introduce or amplified pre-existing F. tularensis? (ii) which features of the “Francisella—Microtus” relationship are crucial for the epidemiology of tularemia? (iii) how virulent and persistent F. tularensis infection is for voles under natural conditions? and (iv) where does the bacterium persist during inter-epizootics? Future research should focus on more integrated, community-based approaches in order to understand the details and dynamics of disease circulation in ecosystems colonized by highly fluctuating hosts.

scholarly journals The shape of the contact–density function matters when modelling parasite transmission in fluctuating populations

2017 ◽  
Vol 4 (11) ◽  
pp. 171308 ◽  
Author(s):  
Benny Borremans ◽  
Jonas Reijniers ◽  
Niel Hens ◽  
Herwig Leirs
Keyword(s):  
Density Function ◽  
Disease Transmission ◽  
Field Data ◽  
Infectious Agent ◽  
Real Data ◽  
Infection Prevalence ◽  
Contact Density ◽  
Rodent Host ◽  
Constant Frequency ◽  
Fluctuating Populations

Models of disease transmission in a population with changing densities must assume a relation between infectious contacts and density. Typically, a choice is made between a constant (frequency-dependence) and a linear (density-dependence) contact–density function, but it is becoming increasingly clear that intermediate, nonlinear functions are more realistic. It is currently not clear, however, what the exact consequences would be of different contact–density functions in fluctuating populations. By combining field data on rodent host ( Mastomys natalensis ) demography, experimentally derived contact–density data, and laboratory and field data on Morogoro virus infection dynamics, we explored the effects of different contact–density function shapes on transmission dynamics and invasion/persistence. While invasion and persistence were clearly affected by the shape of the function, the effects on outbreak characteristics such as infection prevalence and seroprevalence were less obvious. This means that it may be difficult to distinguish between the different shapes based on how well models fit to real data. The shape of the transmission–density function should therefore be chosen with care, and is ideally based on existing information such as a previously quantified contact– or transmission–density relationship or the underlying biology of the host species in relation to the infectious agent.

scholarly journals Zoonotic pathogens in fluctuating common vole (Microtus arvalis) populations: occurrence and dynamics

Parasitology ◽  
2018 ◽  
Vol 146 (3) ◽  
pp. 389-398 ◽  
Author(s):  
Ruth Rodríguez-Pastor ◽  
Raquel Escudero ◽  
Xavier Lambin ◽  
Mª Dolors Vidal ◽  
Horacio Gil ◽  
...  
Keyword(s):  
Density Dependence ◽  
Francisella Tularensis ◽  
Disease Transmission ◽  
Common Vole ◽  
Host Density ◽  
Microtus Arvalis ◽  
Time Lagged ◽  
Additional Influence ◽  
Common Voles ◽  
Pathogen Vector

AbstractDiseases and host dynamics are linked, but their associations may vary in strength, be time-lagged, and depend on environmental influences. Where a vector is involved in disease transmission, its dynamics are an additional influence, and we often lack a general understanding on how diseases, hosts and vectors interact. We report on the occurrence of six zoonotic arthropod-borne pathogens (Anaplasma, Bartonella, Borrelia, Coxiella, Francisella and Rickettsia) in common voles (Microtus arvalis) throughout a population fluctuation and how their prevalence varies according to host density, seasonality and vector prevalence. We detected Francisella tularensis and four species of Bartonella, but not Anaplasma, Borrelia, Coxiella or Rickettsia. Bartonella taylorii and B. grahamii prevalence increased and decreased with current host (vole and mice) density, respectively, and increased with flea prevalence. Bartonella doshiae prevalence decreased with mice density. These three Bartonella species were also more prevalent during winter. Bartonella rochalimae prevalence varied with current and previous vole density (delayed-density dependence), but not with season. Coinfection with F. tularensis and Bartonella occurred as expected from the respective prevalence of each disease in voles. Our results highlight that simultaneously considering pathogen, vector and host dynamics provide a better understanding of the epidemiological dynamics of zoonoses in farmland rodents.

scholarly journals The shape of the contact-density function matters when modelling parasite transmission in fluctuating populations

2017 ◽  
Author(s):  
Benny Borremans ◽  
Jonas Reijniers ◽  
Niel Hens ◽  
Herwig Leirs
Keyword(s):  
Density Function ◽  
Disease Transmission ◽  
Field Data ◽  
Infectious Agent ◽  
Real Data ◽  
Infection Prevalence ◽  
Contact Density ◽  
Rodent Host ◽  
Constant Frequency ◽  
Fluctuating Populations

AbstractModels of disease transmission in a population with changing densities must assume a relation between infectious contacts and density. Typically, a choice is made between a constant (frequency-dependence) and a linear (density-dependence) contact-density function, but it is becoming increasingly clear that intermediate, nonlinear functions intermediate are more realistic. It is currently not clear however what the exact consequences would be of different contact-density functions in fluctuating populations. By combining field data on rodent host (Mastomys natalensis) demography, experimentally-derived contact-density data, and laboratory and field data Morogoro virus infection dynamics, we explored the effects of different contact-density function shapes on transmission dynamics and invasion/persistence. While invasion and persistence were clearly affected by the shape of the function, the effects on outbreak characteristics such as infection prevalence and seroprevalence were less obvious. This means that it may be difficult to distinguish between the different shapes based on how well models fit to real data. The shape of the transmission-density function should therefore be chosen with care, and is ideally based on existing information such as a previously quantified contact- or transmission-density relationship or the underlying biology of the host species in relation to the infectious agent.

scholarly journals Helminth fauna of Microtus cf. arvalis (Rodentia, Cricetidae) in Russia and adjacent countries

2020 ◽  
Vol 21 (5) ◽  
Author(s):  
NADEZHDA Yu. KIRILLOVA ◽  
Alexander Kirillov ◽  
ALEXANDER B. RUCHIN ◽  
MAXIM V. TRUKHACHEV
Keyword(s):  
Common Vole ◽  
Common Species ◽  
Final Host ◽  
Helminth Fauna ◽  
Helminth Species ◽  
Research Areas ◽  
The Common ◽  
Common Voles ◽  
Paratenic Hosts ◽  
Parasitic Worms

Abstract. Kirillova NYu, Kirillov AA, Ruchin AB, Trukhachev MV. 2020. Helminth fauna of Microtus cf. arvalis (Rodentia, Cricetidae) in Russia and adjacent countries. Biodiversitas 21: 1961-1979. The helminth fauna of voles of the Microtus cf. arvalis group is reviewed focusing on the Russian fauna and that of adjacent territories. In total, 61 helminth species have been recorded in these rodents: Trematoda-14, Cestoda-21, Nematoda-25, Acanthocephala-1. The diversity of the helminth community of the common vole is due to the wide species range and abundance of this rodent. M. arvalis is the final host for most of the parasites recorded from this host species. Only 10 cestodes and trematodes species use common voles as intermediate and paratenic hosts. The core of this voles’ helminth fauna is formed by common species that parasitize many different rodent species. The helminth fauna of the common vole has been most intensively studied in Russia, where 45 species of parasitic worms have been recorded in rodents. The similarity of the helminth fauna of the common vole from different study regions is determined by both the geographical proximity of the research areas and the broad distribution of most of the M. cf. arvalis helminth species.

scholarly journals Exploring the Role of Innate Lymphocytes in the Immune System of Bats and Virus-Host Interactions

Viruses ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 150
Author(s):  
Wan Rong Sia ◽  
Yichao Zheng ◽  
Fei Han ◽  
Shiwei Chen ◽  
Shaohua Ma ◽  
...  
Keyword(s):  
Immune System ◽  
Disease Transmission ◽  
Viral Infections ◽  
Current Knowledge ◽  
Future Research ◽  
Global Public Health ◽  
Immune Systems ◽  
Adaptive Immune ◽  
Adaptive Immune Cells ◽  
Innate Lymphocytes

Bats are reservoirs of a large number of viruses of global public health significance, including the ancestral virus for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the causative agent of coronavirus disease 2019 (COVID-19). Although bats are natural carriers of multiple pathogenic viruses, they rarely display signs of disease. Recent insights suggest that bats have a more balanced host defense and tolerance system to viral infections that may be linked to the evolutionary adaptation to powered flight. Therefore, a deeper understanding of bat immune system may provide intervention strategies to prevent zoonotic disease transmission and to identify new therapeutic targets. Similar to other eutherian mammals, bats have both innate and adaptive immune systems that have evolved to detect and respond to invading pathogens. Bridging these two systems are innate lymphocytes, which are highly abundant within circulation and barrier tissues. These cells share the characteristics of both innate and adaptive immune cells and are poised to mount rapid effector responses. They are ideally suited as the first line of defense against early stages of viral infections. Here, we will focus on the current knowledge of innate lymphocytes in bats, their function, and their potential role in host–pathogen interactions. Moreover, given that studies into bat immune systems are often hindered by a lack of bat-specific research tools, we will discuss strategies that may aid future research in bat immunity, including the potential use of organoid models to delineate the interplay between innate lymphocytes, bat viruses, and host tolerance.

scholarly journals Robotics and AI for Teleoperation, Tele-Assessment, and Tele-Training for Surgery in the Era of COVID-19: Existing Challenges, and Future Vision

2021 ◽  
Vol 8 ◽  
Author(s):  
Navid Feizi ◽  
Mahdi Tavakoli ◽  
Rajni V. Patel ◽  
S. Farokh Atashzar
Keyword(s):  
Surgical Procedures ◽  
Disease Transmission ◽  
Healthcare Delivery ◽  
Quality Of Healthcare ◽  
Healthcare Services ◽  
Daily Basis ◽  
Future Research ◽  
Risk Of Infection ◽  
Post Surgery ◽  
Operative Assessment

The unprecedented shock caused by the COVID-19 pandemic has severely influenced the delivery of regular healthcare services. Most non-urgent medical activities, including elective surgeries, have been paused to mitigate the risk of infection and to dedicate medical resources to managing the pandemic. In this regard, not only surgeries are substantially influenced, but also pre- and post-operative assessment of patients and training for surgical procedures have been significantly impacted due to the pandemic. Many countries are planning a phased reopening, which includes the resumption of some surgical procedures. However, it is not clear how the reopening safe-practice guidelines will impact the quality of healthcare delivery. This perspective article evaluates the use of robotics and AI in 1) robotics-assisted surgery, 2) tele-examination of patients for pre- and post-surgery, and 3) tele-training for surgical procedures. Surgeons interact with a large number of staff and patients on a daily basis. Thus, the risk of infection transmission between them raises concerns. In addition, pre- and post-operative assessment also raises concerns about increasing the risk of disease transmission, in particular, since many patients may have other underlying conditions, which can increase their chances of mortality due to the virus. The pandemic has also limited the time and access that trainee surgeons have for training in the OR and/or in the presence of an expert. In this article, we describe existing challenges and possible solutions and suggest future research directions that may be relevant for robotics and AI in addressing the three tasks mentioned above.

scholarly journals Predictive accuracy of a hierarchical logistic model of cumulative SARS-CoV-2 case growth until May 2020

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Levente Kriston
Keyword(s):  
Disease Transmission ◽  
Logistic Model ◽  
Predictive Accuracy ◽  
Future Research ◽  
Cumulative Number ◽  
Epidemiological Models ◽  
First Case ◽  
Distribution Of Resources ◽  
The One ◽  
Models Of Disease

Abstract Background Infectious disease predictions models, including virtually all epidemiological models describing the spread of the SARS-CoV-2 pandemic, are rarely evaluated empirically. The aim of the present study was to investigate the predictive accuracy of a prognostic model for forecasting the development of the cumulative number of reported SARS-CoV-2 cases in countries and administrative regions worldwide until the end of May 2020. Methods The cumulative number of reported SARS-CoV-2 cases was forecasted in 251 regions with a horizon of two weeks, one month, and two months using a hierarchical logistic model at the end of March 2020. Forecasts were compared to actual observations by using a series of evaluation metrics. Results On average, predictive accuracy was very high in nearly all regions at the two weeks forecast, high in most regions at the one month forecast, and notable in the majority of the regions at the two months forecast. Higher accuracy was associated with the availability of more data for estimation and with a more pronounced cumulative case growth from the first case to the date of estimation. In some strongly affected regions, cumulative case counts were considerably underestimated. Conclusions With keeping its limitations in mind, the investigated model may be used for the preparation and distribution of resources during the initial phase of epidemics. Future research should primarily address the model’s assumptions and its scope of applicability. In addition, establishing a relationship with known mechanisms and traditional epidemiological models of disease transmission would be desirable.

scholarly journals Impact of Microtus arvalis and Lepus europaeus on apple trees by trunk bark gnawing

2019 ◽  
Vol 55 (No. 2) ◽  
pp. 142-147
Author(s):  
Josef Suchomel ◽  
Jan Šipoš ◽  
Ladislav Čepelka ◽  
Marta Heroldová
Keyword(s):  
Apple Tree ◽  
Common Vole ◽  
Apple Orchard ◽  
Lepus Europaeus ◽  
Microtus Arvalis ◽  
European Hare ◽  
Bark Damage ◽  
Dead Trees ◽  
Apple Cultivars ◽  
Common Voles

A unique evaluation of the apple tree trunk bark damage caused by common vole and European hare was presented. Damage was found in an apple orchard under organic farming, in Central Moravia (Czech Republic), at 700 m a.s.l. There were two cultivated apple cultivars Red Spring and Melodie/Angold. Damage occurred in winter with the snow cover lasting from December to February. In total 1 012 trees and 95.7% of trees were damaged. The cv. Red Spring was damaged more than cv. Melodie/Angold. Almost 90% of the dead trees were killed by common voles. While hares damaged both cultivars equally, voles damaged the cv. Red Spring to a significantly greater extent (P = 0.04). The study confirms the need of further research on the development of methodologies for orchard protection from damage caused by small mammals.

scholarly journals Out of the Reservoir: Phenotypic and Genotypic Characterization of a Novel Cowpox Virus Isolated from a Common Vole

2015 ◽  
Vol 89 (21) ◽  
pp. 10959-10969 ◽  
Author(s):  
Donata Hoffmann ◽  
Annika Franke ◽  
Maria Jenckel ◽  
Aistė Tamošiūnaitė ◽  
Julia Schluckebier ◽  
...  
Keyword(s):  
Respiratory Symptoms ◽  
Clinical Symptoms ◽  
Common Vole ◽  
Reservoir Host ◽  
High Dose ◽  
Cowpox Virus ◽  
Common Voles ◽  
Highly Virulent

ABSTRACTThe incidence of human cowpox virus (CPXV) infections has increased significantly in recent years. Serological surveys have suggested wild rodents as the main CPXV reservoir. We characterized a CPXV isolated during a large-scale screening from a feral common vole. A comparison of the full-length DNA sequence of this CPXV strain with a highly virulent pet rat CPXV isolate showed a sequence identity of 96%, including a large additional open reading frame (ORF) of about 6,000 nucleotides which is absent in the reference CPXV strain Brighton Red. Electron microscopy analysis demonstrated that the vole isolate, in contrast to the rat strain, forms A-type inclusion (ATI) bodies with incorporated virions, consistent with the presence of completeatiandp4cgenes. Experimental infections showed that the vole CPXV strain caused only mild clinical symptoms in its natural host, while all rats developed severe respiratory symptoms followed by a systemic rash. In contrast, common voles infected with a high dose of the rat CPXV showed severe signs of respiratory disease but no skin lesions, whereas infection with a low dose led to virus excretion with only mild clinical signs. We concluded that the common vole is susceptible to infection with different CPXV strains. The spectrum ranges from well-adapted viruses causing limited clinical symptoms to highly virulent strains causing severe respiratory symptoms. In addition, the low pathogenicity of the vole isolate in its eponymous host suggests a role of common voles as a major CPXV reservoir, and future research will focus on the correlation between viral genotype and phenotype/pathotype in accidental and reservoir species.IMPORTANCEWe report on the first detection and isolation of CPXV from a putative reservoir host, which enables comparative analyses to understand the infection cycle of these zoonotic orthopox viruses and the relevant genes involved.In vitrostudies, including whole-genome sequencing as well asin vivoexperiments using the Wistar rat model and the vole reservoir host allowed us to establish links between genomic sequences and thein vivoproperties (virulence) of the novel vole isolate in comparison to those of a recent zoonotic CPXV isolated from pet rats in 2009. Furthermore, the role of genes present only in a reservoir isolate can now be further analyzed. These studies therefore allow unique insights and conclusions about the role of the rodent reservoir in CPXV epidemiology and transmission and about the zoonotic threat that these viruses represent.

Prey choice of Tengmalm's owls (Aegolius funereus funereus): preference for substandard individuals?

1996 ◽  
Vol 74 (5) ◽  
pp. 816-823 ◽  
Author(s):  
Vesa Koivunen ◽  
Erkki Korpimäki ◽  
Harri Hakkarainen ◽  
Kai Norrdahl
Keyword(s):  
Common Shrew ◽  
Common Vole ◽  
Clethrionomys Glareolus ◽  
Prey Choice ◽  
Aegolius Funereus ◽  
Nest Boxes ◽  
Bank Voles ◽  
The Common ◽  
Common Voles ◽  
Prey Items

Errington proposed that predators mainly kill substandard prey, because dominant individuals force subordinate ones into poor habitats, where the predation risk is higher. We studied the prey choice of breeding male Tengmalm's owls (Aegolius funereus funereus) in 1992, when vole densities crashed. We trapped small mammals in the main habitat types in 21 owl territories, and simultaneously identified prey items cached by the same owls in their nest boxes. The main prey of owls in western Finland are the common vole (Microtus epiroticus), field vole (M. agrestis), bank vole (Clethrionomys glareolus), and common shrew (Sorex araneus). Common voles were the preferred prey of owls, followed by field voles, bank voles, and common shrews. Prey captured by owls tended to be lighter and smaller than those available in the field. This tendency was significant for field voles and common shrews. Field voles, common voles, and female common shrews captured by owls tended to have more internal fat than those available in the field. This tendency was significant for male field voles and female common shrews. Owls appeared to choose small individuals of some, but not all, prey species, and that these prey items were not in poor physiological condition.

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