An economic evaluation of potential surveillance strategies for the control of Bovine Viral Diarrhoea Virus in England. [200]

Economic analysis of surveillance systems is valuable for decision-making: it shows the consequences of different alternatives and helps ensure that maximum benefit from disease mitigation is obtained from a given amount of resources. Bovine viral diarrhoea virus (BVDV) is a non-notifiable endemic disease of cattle in England with a significant economic impact, yet it lacks a national control and a decision-making process for its elimination. To improve coordination of existing local schemes a surveillance system is needed to establish prevalence levels in order to develop an efficient control strategy. Methods: Therefore a study was designed to holistically develop and evaluate BVDV surveillance for England that would enhance resource use efficiency. A proposed surveillance framework included a centralized data coordination and management system, and was compared to the current system (the baseline) with cost-effectiveness analysis that utilises a new surveillance evaluation tool recently developed by the project RISKSUR (www.fp7-risksur.eu). Surveillance costs were being estimated using publications and interviews with decision-makers from the different existing schemes. The effectiveness is expressed as the ability of the system to detect disease in an endemic situation. A cost-effectiveness analysis looking at technical outcome is conducted to look at different surveillance options, also taking into account different ways of coordinating and managing the data in a centralized way. Results: Results indicate that a Surveillance Centre for BVDV would cost £60,000 per annum for personnel and overheads. Further results, as well as further sensitivity analysis on their robustness, will be presented. Conclusion: The estimated improvement in effectiveness demonstrates that such a Centre would improve sensitivity of surveillance and if well linked to a national control programme lead to economic gains. Relevance: An evaluation of the cost-effectiveness of an improved BVDV surveillance system presents a strong case for the implementation of the improved strategy, presenting decision-makers with the requisite evidence of a BVDV control programme. (Texte intégral

Active animal health surveillance in European Union Member States: gaps and opportunities

Animal health surveillance enables the detection and control of animal diseases including zoonoses. Under the EU-FP7 project RISKSUR, a survey was conducted in 11 EU Member States and Switzerland to describe active surveillance components in 2011 managed by the public or private sector and identify gaps and opportunities. Information was collected about hazard, target population, geographical focus, legal obligation, management, surveillance design, risk-based sampling, and multi-hazard surveillance. Two countries were excluded due to incompleteness of data. Most of the 664 components targeted cattle (26·7%), pigs (17·5%) or poultry (16·0%). The most common surveillance objectives were demonstrating freedom from disease (43·8%) and case detection (26·8%). Over half of components applied risk-based sampling (57·1%), but mainly focused on a single population stratum (targeted risk-based) rather than differentiating between risk levels of different strata (stratified risk-based). About a third of components were multi-hazard (37·3%). Both risk-based sampling and multi-hazard surveillance were used more frequently in privately funded components. The study identified several gaps (e.g. lack of systematic documentation, inconsistent application of terminology) and opportunities (e.g. stratified risk-based sampling). The greater flexibility provided by the new EU Animal Health Law means that systematic evaluation of surveillance alternatives will be required to optimize cost-effectiveness

The epidemiology of mild cognitive impairment (MCI) and Alzheimer’s disease (AD) in community-living seniors: protocol of the MemoVie cohort study, Luxembourg

BACKGROUND: Cognitive impairment and Alzheimer’s disease (AD) are increasingly considered a major public health problem. The MemoVie cohort study aims to investigate the living conditions or risk factors under which the normal cognitive capacities of the senior population in Luxembourg (≥ 65 year-old) evolve (1) to mild cognitive impairment (MCI) – transitory non-clinical stage – and (2) to AD. Identifying MCI and AD predictors undeniably constitutes a challenge in public health in that it would allow interventions which could protect or delay the occurrence of cognitive disorders in elderly people. In addition, the MemoVie study sets out to generate hitherto unavailable data, and a comprehensive view of the elderly population in the country. METHODS/DESIGN: The study has been designed with a view to highlighting the prevalence in Luxembourg of MCI and AD in the first step of the survey, conducted among participants selected from a random sample of the general population. A prospective cohort is consequently set up in the second step, and appropriate follow-up of the non-demented participants allows improving the knowledge of the preclinical stage of MCI. Case-control designs are used for cross-sectional or retrospective comparisons between outcomes and biological or clinical factors. To ensure maximal reliability of the information collected, we decided to opt for structured face to face interviews. Besides health status, medical and family history, demographic and socio-cultural information are explored, as well as education, habitat network, social behavior, leisure and physical activities. As multilingualism is expected to challenge the cognitive alterations associated with pathological ageing, it is additionally investigated. Data relative to motor function, including balance, walk, limits of stability, history of falls and accidents are further detailed. Finally, biological examinations, including ApoE genetic polymorphism are carried out. In addition to standard blood parameters, the lipid status of the participants is subsequently determined from the fatty acid profiles in their red blood cells. The study obtained the legal and ethical authorizations. DISCUSSION: By means of the multidisciplinary MemoVie study, new insights into the onset of cognitive impairment during aging should be put forward, much to the benefit of intervention strategies as a whole

Vestibular migraine: Diagnostic criteria (Update)

This paper presents diagnostic criteria for vestibular migraine, jointly formulated by the Committee for Classification of Vestibular Disorders of the Bárány Society and the Migraine Classification Subcommittee of the International Headache Society (IHS). It contains a literature update while the original criteria from 2012 were left unchanged. The classification defines vestibular migraine and probable vestibular migraine. Vestibular migraine was included in the appendix of the third edition of the International Classification of Headache Disorders (ICHD-3, 2013 and 2018) as a first step for new entities, in accordance with the usual IHS procedures. Probable vestibular migraine may be included in a later version of the ICHD, when further evidence has accumulated. The diagnosis of vestibular migraine is based on recurrent vestibular symptoms, a history of migraine, a temporal association between vestibular symptoms and migraine symptoms and exclusion of other causes of vestibular symptoms. Symptoms that qualify for a diagnosis of vestibular migraine include various types of vertigo as well as head motion-induced dizziness with nausea. Symptoms must be of moderate or severe intensity. Duration of acute episodes is limited to a window of between 5 minutes and 72 hours

Descriptive Profiles for Sets of Alternatives in Multiple Criteria Decision Aid

International audienceIn the context of Multiple Criteria Decision Aid, a decision-maker may be faced at any time with the task of analyzing one or several sets of alternatives, irrespective of the decision he is about to make. As in this case the alternatives may express contrasting gains and losses on the criteria on which they are evaluated, and while the sets that are presented to the decision-maker may potentially be large, the task of analysing them becomes a difficult one. Therefore the need to reduce these sets to a more concise representation is very important. Classically, profiles that describe sets of alternatives may be found in the context of the sorting problem, however they are either given beforehand by the decision-maker or determined from a set of assignment examples. We would therefore like to extend such profiles, as well as propose new ones, in order to characterize any set of alternatives. For each of them, we present several approaches for extracting them, which we then compare with respect to their performance

The use of a Psoroptes ovis serodiagnostic test for the analysis of a natural outbreak of sheep scab

<p>Abstract</p> <p>Background</p> <p>Sheep scab is a highly contagious disease of sheep caused by the ectoparasitic mite <it>Psoroptes ovis</it>. The disease is endemic in the UK and has significant economic impact through its effects on performance and welfare. Diagnosis of sheep scab is achieved through observation of clinical signs e.g. itching, pruritis and wool loss and ultimately through the detection of mites in skin scrapings. Early stages of infestation are often difficult to diagnose and sub-clinical animals can be a major factor in disease spread. The development of a diagnostic assay would enable farmers and veterinarians to detect disease at an early stage, reducing the risk of developing clinical disease and limiting spread.</p> <p>Methods</p> <p>Serum samples were obtained from an outbreak of sheep scab within an experimental flock (n = 480 (3 samples each from 160 sheep)) allowing the assessment, by ELISA of sheep scab specific antibody prior to infestation, mid-outbreak (combined with clinical assessment) and post-treatment.</p> <p>Results</p> <p>Analysis of pre-infestation samples demonstrated low levels of potential false positives (3.8%). Of the 27 animals with clinical or behavioural signs of disease 25 tested positive at the mid-outbreak sampling period, however, the remaining 2 sheep tested positive at the subsequent sampling period. Clinical assessment revealed the absence of clinical or behavioural signs of disease in 132 sheep, whilst analysis of mid-outbreak samples showed that 105 of these clinically negative animals were serologically positive, representing potential sub-clinical infestations.</p> <p>Conclusions</p> <p>This study demonstrates that this ELISA test can effectively diagnose sheep scab in a natural outbreak of disease, and more importantly, highlights its ability to detect sub-clinically infested animals. This ELISA, employing a single recombinant antigen, represents a major step forward in the diagnosis of sheep scab and may prove to be critical in any future control program.</p

Economic evaluation of animal health surveillance - moving from infancy to adolescence? [224]

Purpose Population growth, changes in food systems, urbanisation, and climate change linked in a web of global trade throw up new challenges for disease control. Animal health surveillance is widely recognized as an effective tool for disease management, but investment is often low and poorly targeted. For European decision-makers, economic criteria are important in decision-making for surveillance. Yet, economic evaluations of surveillance (EES) are sparse and available guidelines for the evaluation of surveillance fail to provide guidance on systematic economic appraisal. Methods The RISKSUR consortium (www.fp7-risksur.eu) that investigates novel approaches for cost-effective surveillance has developed a web-based surveillance design and evaluation tool directed at users with advanced surveillance knowledge and skills. A key innovative feature is the provision of user-friendly and practical guidance for the design and implementation of EES. Economic theory underpinning EES is explained and challenges that accrue from application of differing paradigms highlighted. In particular, the three-variable relationship between surveillance, intervention and loss avoidance; value of information, and non-monetary benefits are elaborated and linked to economic analysis methods commonly used in animal health. Results The application of the tool for EES for classical and African swine fever, bovine viral diarrhoea, avian influenza, and Salmonella Dublin infection in five European countries showed that cost-benefit, cost-effectiveness, and least-cost analyses were the methods of choice. Difficulties encountered include estimation of fixed and variable costs, non-monetary benefits, co-benefits resulting from using synergies, and the selection of meaningful effectiveness measures. Selected results will be presented. Conclusions and relevance The tool promotes understanding of critical concepts, suitable methods, data and time requirements and is expected to nurture the use of EES, which is still in its infancy. In the long term, this will increase professional capacity and help to address the problem of resource allocation for surveillance to the benefit of all. (Texte intégral

Electre Methods: Main Features and Recent Developments

We present main characteristics of Electre family methods, designed for multiple criteria decision aiding. These methods use as a preference model an outranking relation in the set of actions - it is constructed in result of concordance and non-discordance tests involving a specific input preference information. After a brief description of the constructivist conception in which the Electre methods are inserted, we present the main features of these methods. We discuss such characteristic features as: the possibility of taking into account positive and negative reasons in the modeling of preferences, without any need for recoding the data; using of thresholds for taking into account the imperfect knowledge of data; the absence of systematic compensation between "gains" and "losses". The main weaknesses are also presented. Then, some aspects related to new developments are outlined. These are related to some new methodological developments, new procedures, axiomatic analysis, software tools, and several other aspects. The paper ends with conclusions

Development and evaluation of an accelerometry system based on inverted pendulum to measure and analyze human balance

An accelerometry system was developed based on the inverted pendulum model and its effectiveness to measure the body's sway path and sway angle was verified in healthy adult volunteers. Sway path represents the body’s movement from its center of mass position projected to the ground surface while sway angle represents the body's orientation from the vertical. Mathematical models were developed to determine the sway displacement and sway angle from the accelerometry system. The resulting values were compared with the manual measurements obtained from a plumb bob based setup and found to correlate closely. Using the developed system, measures that analyzed the contribution of the visual, somatosensory and vestibular systems to balance were obtained. It was found that the accelerometry system followed the principle of motion of an inverted pendulum and provided information that can assist in better understanding of balance and thus it may assist clinicians in diagnosing balance dysfunctions