1,905 research outputs found
Results of the surveillance of regulated contagious diseases in the french wildlife
The FrenchMinistry of Agriculture, the National Hunting andWildlife Agency (ONCFS) and the hunters’
associations are increasingly concerned with the impact of wildlife diseases on livestock and human
health. The demographic growth of some wild species is further increasing this risk. In France, wildlife
diseases aremonitored passively through the SAGIR network, whose objective is to diagnose the causes
of wildlife mortality, and actively by targeting certain species and diseases with a major economic
or public health impact. This surveillance programhas shown for instance that wild boars act as a reservoir
for Brucella suis biovar 2 and the Aujeszky’s disease virus, and that they are responsible for the
contamination of open-air pig farms, as well as for the persistence for over fifteen years of the virus
of classical swine fever in the North-East of France and in other parts of Europe. Oral vaccination of
wild boars had been thus implemented since 2004 in order to control the enzooty. Since 2001, cases
of bovine tuberculosis due to Mycobacterium bovis have been identified in red deer and wild boar
in several areas of France, which threaten disease-free livestock. Likewise, the question of a possible
role of wild ruminants in the epidemiology of Bluetongue disease is being raised. Finally, wild
birds constitute uncontrollable reservoirs for influenza andWest Nile viruses, among others, and may
threaten domestic poultry, humans or horses. The sanitary status of wild species is thus increasingly
taken into account in the management and control of livestock diseases.Les ministères chargés de
l'Agriculture et le monde cynégétique sont de plus en plus préoccupés par le risque
sanitaire que peut représenter la faune sauvage pour les animaux d'élevage et l'homme. Ce
risque est aggravé par la croissance démographique de certaines espèces sauvages. En France,
l'épidémiosurveillance des maladies de la faune sauvage est assurée par le réseau SAGIR dont
l'objectif est de diagnostiquer les causes de mortalité des animaux sauvages (surveillance
passive), ainsi que par la mise en oeuvre de plans de surveillance ciblés sur certaines
espèces et sur des maladies à impact économique ou zoonotique majeur (surveillance active).
Les résultats de cette surveillance montrent, par exemple, que le sanglier est un réservoir
de Brucella suis biovar 2 et du virus de la maladie d'Aujeszky, responsable de la
contamination d'élevages de porcs en plein air, et qu'il entretient depuis plus de quinze
ans le virus de la peste porcine classique dans le nord-est de la France, comme dans
d'autres régions d'Europe. Depuis 2001, des cas de tuberculose bovine à Mycobacterium bovis
ont été découverts chez les cerfs et les sangliers dans plusieurs départements, laissant
peser un risque de recontamination de cheptels bovins indemnes. De même, la question du rôle
joué par les ruminants sauvages dans l'épidémiologie de la fièvre catarrhale ovine est
posée. Enfin, les oiseaux sauvages, réservoirs incontrôlables des virus influenza et du
virus West Nile pour ne citer qu'eux, peuvent représenter un risque pour les volailles,
l'homme ou le cheval. De ce fait, la faune sauvage est maintenant prise en compte dans les
mesures de gestion sanitaire des maladies animales
Coating carbon nanotubes with a polystyrene-based polymer protects against pulmonary toxicity
BACKGROUND: carbon nanotubes (CNT) can have adverse effects on health. Therefore, minimizing the risk associated with CNT exposure is of crucial importance. The aim of this work was to evaluate if coating multi-walled CNT (MWCNT) with polymers could modify their toxicity, thus representing a useful strategy to decrease adverse health effects of CNT. We used industrially-produced MWCNT uncoated (NT1) or coated (50/50 wt%) with acid-based (NT2) or polystyrene-based (NT3) polymer, and exposed murine macrophages (RAW 264.7 cell line) or Balb/c mice by intratracheal administration. Biological experiments were performed both in vitro and in vivo, examining time- and dose-dependent effects of CNT, in terms of cytotoxicity, expression of genes and proteins related to oxidative stress, inflammation and tissue remodeling, cell and lung tissue morphology (optical and transmission electron microscopy), and bronchoalveolar lavage fluid content analysis.RESULTS: extensive physico-chemical characterization of MWCNT was performed, and showed, although similar dimensions for the 3 MWCNT, a much smaller specific surface area for NT2 and NT3 as compared to NT1 (54.1, 34 and 227.54 m(2)/g respectively), along with different surface characteristics. MWCNT-induced cytotoxicity, oxidative stress, and inflammation were increased by acid-based and decreased by polystyrene-based polymer coating both in vitro in murine macrophages and in vivo in lung of mice monitored for 6 months.CONCLUSIONS: these results demonstrate that coating CNT with polymers, without affecting their intrinsic structure, may constitute a useful strategy for decreasing CNT toxicity, and may hold promise for improving occupational safety and that of general the user
Multi-species temporal network of livestock movements for disease spread
Introduction:
The objective of this study is to show the importance of interspecies links and temporal network dynamics of a multi-species livestock movement network. Although both cattle and sheep networks have been previously studied, cattle-sheep multi-species networks have not generally been studied in-depth. The central question of this study is how the combination of cattle and sheep movements affects the potential for disease spread on the combined network.
Materials and methods:
Our analysis considers static and temporal representations of networks based on recorded animal movements. We computed network-based node importance measures of two single-species networks, and compared the top-ranked premises with the ones in the multi-species network. We propose the use of a measure based on contact chains calculated in a network weighted with transmission probabilities to assess the importance of premises in an outbreak. To ground our investigation in infectious disease epidemiology, we compared this suggested measure with the results of disease simulation models with asymmetric probabilities of transmission between species.
Results:
Our analysis of the temporal networks shows that the premises which are likely to drive the epidemic in this multi-species network differ from the ones in both the cattle and the sheep networks. Although sheep movements are highly seasonal, the estimated size of an epidemic is significantly larger in the multi-species network than in the cattle network, independently of the period of the year. Finally, we demonstrate that a measure based on contact chains allow us to identify around 30% of the key farms in a simulated epidemic, ignoring markets, whilst static network measures identify less than 10% of these farms.
Conclusion:
Our results ascertain the importance of combining species networks, as well as considering layers of temporal livestock movements in detail for the study of disease spread
Increased Metabolic Activity Detected By Flim In Human Breast Cancer Cells With Desmoplastic Reaction: A Pilot Study
Introduction: In breast cancer (BC), desmoplastic reaction, assembled primarily by fibroblasts, is associated with unfavorable prognosis, but the reason of this fact remains still unclear. In this context, nonlinear optics microscopy, including Fluorescence Lifetime Imaging Microscopy (FLIM), has provided advancement in cellular metabolism research. In this paper, our purpose is to differentiate BC cells metabolism with or without contact to desmoplastic reaction. Formalin fixed, paraffin embedded samples were used at different points of hematoxylin stained sections. Methodology: Sections from 14 patients with invasive ductal breast carcinoma were analyzed with FLIM methodology to NAD(P)H and FAD fluorescence lifetime on a Confocal Upright LSM780 NLO device (Carl Zeiss AG, Germany). Quantification of the fluorescence lifetime and fluorescence intensity was evaluated by SPC Image software (Becker & Hickl) and ImageJ (NIH), respectively. Optical redox ratio was calculated by dividing the FAD fluorescence intensity by NAD(P) H fluorescence intensity. Data value for FLIM measurements and fluorescence intensities were calculated using Wilcoxon test; p< 0.05 was considered significant. Results: BC cells in contact with desmoplastic reaction presented a significantly lower NAD(P) H and FAD fluorescence lifetime. Furthermore, optical redox ratio was also lower in these tumor cells. Conclusion: Our results suggest that contact of BC cells with desmoplastic reaction increase their metabolic activity, which might explain the adverse prognosis of cases associated with higher peritumoral desmoplastic reaction.953
Evaluation of Three Medetomidine-Based Anesthetic Protocols in Free-Ranging Wild Boars (Sus scrofa)
Three medetomidine-based drug protocols were compared by evaluating time courses, reliability and physiological effects in wild boars. A total of 21 cage-trapped wild boars (Sus scrofa) were immobilized using one of the following drug combinations; MTZ: medetomidine (0.2 mg/kg) + tiletamine-zolazepam (2.0 mg/kg), MK: medetomidine (0.15 mg/kg) + ketamine (5 mg/kg), and MKB: medetomidine (0.1 mg/kg) + ketamine (5.0 mg/kg) + butorphanol (0.2 mg/kg). Induction time, recovery time, and physiological variables were recorded and arterial blood gas analysis measured twice, before and after 15 min of oxygen supplementation (0.5-1.0 L/min). For reversal, 4 mg of atipamezole per mg of medetomidine was administered intramuscularly. The boars recovered in the cage and were released once ataxia resolved. The MK group had significantly longer recovery times (mean 164 min +/- 79 SD) compared to the other groups. MKB elicited longer and incomplete induction compared to the other groups (mean induction time 20 min +/- 10 SD), decreasing the efficiency of the capture and increasing the risk of hyperthermia. Both ketamine-based protocols required additional ketamine intramuscularly to prolong the anesthesia after 20-40 min from induction. Agreement between the pulse oximeter and the blood gas analyzer was low, with the pulse oximeter underestimating the real values of arterial oxyhemoglobin saturation, particularly at higher readings. Mild acute respiratory acidosis (PaCO2 45-60 mmHg) and mild to moderate hypoxemia (PaO2 69-80 mmHg) occurred in most boars, regardless of the treatment group but especially in the MKB group. The acid-base status improved and hypoxemia resolved in all boars during oxygen supplementation, with the PaO2 rising above the physiological reference range (81.6-107.7 mmHg) in many individuals. MK and MKB induced safe and reliable immobilization of wild boars for at least 20 min. Supplemental oxygen delivery is recommended in order to prevent hypoxemia in wild boars immobilized with the protocols used in the present study. Long and ataxic recoveries occurred in most animals, regardless of the protocol, but especially in the MKB group
Influence du contexte paysager sur les attaques de processionnaire du pin en ville. Quelles perspectives de méthodes de lutte alternatives ?
We conducted an inventory of all the potential host trees of this species and of its winter tents over an urban area of about 6500 ha. Here we present the preliminary results of a spatial ecology approach and of a neighbourhood analysis exploring relationships between the level of infestation on a given tree and the features of the other host trees occurring around it. The ultimate goal of this work is to help defining urban green infrastructures unfavourable to the spread of this pest.La processionnaire du pin est un insecte défoliateur et urticant inféodé à des résineux forestiers. Elle se propage dans les milieux non forestiers en utilisant les plantations ornementales de ses arbres-hôtes. Dans les zones urbanisées, sa présence pose des problèmes de santé publique auxquels les collectivités territoriales doivent faire face. Nous avons réalisé un inventaire de tous les pins, cèdres et Douglas, et des nids d’hiver qu’ils hébergent, sur le territoire de cinq communes de l’agglomération orléanaise. Nous avons commencé à conduire sur ce jeu de données des analyses d’écologie spatiale et des analyses de voisinage prenant en compte l’influence sur le niveau d’infestation d’un arbre des caractéristiques des autres arbres-hôtes présents dans son environnement. Nous présentons ici les résultats préliminaires de cette approche paysagère en milieu urbain. A terme, l’objectif de ce travail est d’explorer les possibilités de concevoir des infrastructures vertes qui, au lieu de fournir des corridors d’expansion à cette espèce, pourraient en réduire le niveau de nuisance
Mycobacterium bovis genomics reveals transmission of infection between cattle and deer in Ireland
Control of bovine tuberculosis (bTB), caused by Mycobacterium bovis, in the Republic of Ireland costs €84 million each year. Badgers are recognised as being a wildlife source for M. bovis infection of cattle. Deer are thought to act as spillover hosts for infection; however, population density is recognised as an important driver in shifting their epidemiological role, and deer populations across the country have been increasing in density and range. County Wicklow represents one specific area in the Republic of Ireland that has had consistently high bTB prevalence for over a decade, despite control operations in both cattle and badgers. The area is also known to have a high density of deer. Our research used whole genome sequencing of M. bovis sourced from infected cattle, deer, and badgers in County Wicklow to evaluate whether the epidemiological role of deer could have shifted from spillover host to source. Our analyses reveal that cattle and deer share highly similar M. bovis strains suggesting that transmission between these species is occurring in the area. In addition, the high level of diversity observed in the sampled deer population suggests deer may be acting as a source of infection for local cattle populations. These findings have important implications for the control and ultimate eradication of bTB in Ireland
Management of a wild reservoir : Swine fever in European wild boars (sus scrofa)
Classical swine fever (CSF) is a disease affecting wild and domestic Suidae. Wild boars (Sus scrofa) are
considered as a reservoir for the disease, as CSF may persist for years in certain wild populations. The
presence of this infection is a threat for the pig industry in the European Union where most of the
member States are free of CSF.We describe the possible outcomes of an outbreak of CSF in wild animals,
as well as the factors likely to influence the virus transmission and persistence. We also detail
the management measures that were tested to date to prevent geographical spreading from the
infected zones, and to eradicate CSF within the infected areas. The complexity of health measures
dealing with an outbreak within natural populations is explained, with further details on the vaccination
approach implemented in France since 2004.La peste porcine classique
(PPC) est une maladie virale des Suidés domestiques et sauvages. Le sanglier (Sus scrofa)
est considéré comme un réservoir de PPC car la maladie peut persister plusieurs années dans
certaines populations sauvages. Or la présence de cette infection représente une menace pour
la filière porcine de l'union européenne dont la plupart des États membres sont indemnes.
Nous présentons ici les évolutions possibles d'un foyer sauvage de PPC en déclinant les
facteurs probables de la transmission et de la persistance du virus. Nous abordons ensuite
les différents moyens de gestion qui ont été mis en place jusqu'à aujourd'hui pour empêcher
l'extension des zones infectées, et permettre l'éradication des foyers au sein des zones
infectées. L'accent est mis sur la complexité de la gestion sanitaire d'un foyer en
population naturelle. Un développement plus particulier est consacré à la gestion vaccinale
qui est mise en oeuvre en France depuis 2004
New Insights on the Management of Wildlife Diseases Using Multi-State Recapture Models: The Case of Classical Swine Fever in Wild Boar
The understanding of host-parasite systems in wildlife is of increasing interest in relation to the risk of emerging diseases in livestock and humans. In this respect, many efforts have been dedicated to controlling classical swine fever (CSF) in the European Wild Boar. But CSF eradication has not always been achieved even though vaccination has been implemented at a large-scale. Piglets have been assumed to be the main cause of CSF persistence in the wild since they appeared to be more often infected and less often immune than older animals. However, this assumption emerged from laboratory trials or cross-sectional surveys based on the hunting bags.In the present paper we conducted a capture-mark-recapture study in free-ranging wild boar piglets that experienced both CSF infection and vaccination under natural conditions. We used multi-state capture recapture models to estimate the immunization and infection rates, and their variations according to the periods with or without vaccination. According to the model prediction, 80% of the infected piglets did not survive more than two weeks, while the other 20% quickly recovered. The probability of becoming immune did not increase significantly during the summer vaccination sessions, and the proportion of immune piglets was not higher after the autumn vaccination.Given the high lethality of CSF in piglets highlighted in our study, we consider unlikely that piglets could maintain the chain of CSF virus transmission. Our study also revealed the low efficacy of vaccination in piglets in summer and autumn, possibly due to the low palatability of baits to that age class, but also to the competition between baits and alternative food sources. Based on this new information, we discuss the prospects for the improvement of CSF control and the interest of the capture-recapture approach for improving the understanding of wildlife diseases
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