105 research outputs found

    Investigating poultry trade patterns to guide avian influenza surveillance and control: a case study in Vietnam

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    Live bird markets are often the focus of surveillance activities monitoring avian influenza viruses (AIV) circulating in poultry. However, in order to ensure a high sensitivity of virus detection and effectiveness of management actions, poultry management practices features influencing AIV dynamics need to be accounted for in the design of surveillance programmes. In order to address this knowledge gap, a cross-sectional survey was conducted through interviews with 791 traders in 18 Vietnamese live bird markets. Markets greatly differed according to the sources from which poultry was obtained, and their connections to other markets through the movements of their traders. These features, which could be informed based on indicators that are easy to measure, suggest that markets could be used as sentinels for monitoring virus strains circulating in specific segments of the poultry production sector. AIV spread within markets was modelled. Due to the high turn-over of poultry, viral amplification was likely to be minimal in most of the largest markets. However, due to the large number of birds being introduced each day, and challenges related to cleaning and disinfection, environmental accumulation of viruses at markets may take place, posing a threat to the poultry production sector and to public health

    The Winter Worries of Bats : Past and Present Perspectives on Winter Habitat and Management of Cave Hibernating Bats

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    Winter is a time of fascinating changes in biology for cave-hibernating bats, but it is also a time of vulnerability. Unsurprisingly, assessments of winter habitat for these mammals and how it can be managed have been a focus of many researchers involved with the North American Society for Bat Research over the last 50 years. Over this time, a paradigm shift has occurred in the way scientists think about factors driving selection of winter habitat, especially temperature. To illustrate this change, we review three hypotheses seeking to explain microclimate selection in cavernicolous bats. The first, which we call the “Colder is Better Hypothesis,” posits that bats should select cold microclimates that minimize energy expenditure. The “Hibernation Optimization Hypothesis” suggests that bats should select microclimates that reduce expression of torpor to balance energy conservation against non-energetic costs of hibernation. Finally, the “Thrifty Female Hypothesis” asserts that females should select colder microclimates than males to conserve energy for reproduction. We discuss these hypotheses and the shift from viewing hibernation as a phenomenon driven solely by the need to conserve energy in the context of hibernacula management in North America. We focus on both historical and recent conservation threats, most notably alteration of thermal regimes and the disease white-nose syndrome. We urge against returning to an over-simplified view of winter habitat selection in response to our current conservation challenges.Peer reviewe

    Effectiveness of an online group course for adolescents and young adults with depressive symptoms: study protocol for a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Depression is a common condition whose first onset is usually in late adolescence or early adulthood. Internet-based interventions are an effective treatment approach to depression. The aim of this study is to investigate the effectiveness of a Dutch online cognitive-behavioural group course known as Master Your Mood (<it>Grip op Je Dip</it>) for young people reporting depressive symptoms. Secondary research questions involve maintenance of effect at 6 months, mediators, and predictors of better outcomes.</p> <p>Methods</p> <p>We will conduct a randomised controlled trial (RCT) in which 244 young people aged 16-25 are randomly allocated to the Grip op Je Dip (GOJD) online group course or to a waiting list control group. The participants will be recruited from the general population. The primary outcome measure will be the severity of depressive symptoms according to the Center for Epidemiological Studies Depression Scale (CES-D). Other outcomes will include anxiety (Hospital Anxiety and Depression Scale-Anxiety, HADS) and mastery (Mastery Scale). Assessments will take place in both groups at baseline and three months later. Effect maintenance will be studied in the GOJD group six months after baseline, with missing data imputed using the expectation-maximisation method. Mediators and predictors of better outcomes will also be identified.</p> <p>Discussion</p> <p>The trial should add to the body of knowledge on the effectiveness of Internet-based interventions for depression. To our knowledge, this will be the first RCT on an online group intervention in this field.</p> <p>Trial registration</p> <p><a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=NTR1694">NTR1694</a></p

    Frequent Arousal from Hibernation Linked to Severity of Infection and Mortality in Bats with White-Nose Syndrome

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    White-nose syndrome (WNS), an emerging infectious disease that has killed over 5.5 million hibernating bats, is named for the causative agent, a white fungus (Geomyces destructans (Gd)) that invades the skin of torpid bats. During hibernation, arousals to warm (euthermic) body temperatures are normal but deplete fat stores. Temperature-sensitive dataloggers were attached to the backs of 504 free-ranging little brown bats (Myotis lucifugus) in hibernacula located throughout the northeastern USA. Dataloggers were retrieved at the end of the hibernation season and complete profiles of skin temperature data were available from 83 bats, which were categorized as: (1) unaffected, (2) WNS-affected but alive at time of datalogger removal, or (3) WNS-affected but found dead at time of datalogger removal. Histological confirmation of WNS severity (as indexed by degree of fungal infection) as well as confirmation of presence/absence of DNA from Gd by PCR was determined for 26 animals. We demonstrated that WNS-affected bats aroused to euthermic body temperatures more frequently than unaffected bats, likely contributing to subsequent mortality. Within the subset of WNS-affected bats that were found dead at the time of datalogger removal, the number of arousal bouts since datalogger attachment significantly predicted date of death. Additionally, the severity of cutaneous Gd infection correlated with the number of arousal episodes from torpor during hibernation. Thus, increased frequency of arousal from torpor likely contributes to WNS-associated mortality, but the question of how Gd infection induces increased arousals remains unanswered

    Adaptation of mammalian host-pathogen interactions in a changing arctic environment

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    Many arctic mammals are adapted to live year-round in extreme environments with low winter temperatures and great seasonal variations in key variables (e.g. sunlight, food, temperature, moisture). The interaction between hosts and pathogens in high northern latitudes is not very well understood with respect to intra-annual cycles (seasons). The annual cycles of interacting pathogen and host biology is regulated in part by highly synchronized temperature and photoperiod changes during seasonal transitions (e.g., freezeup and breakup). With a warming climate, only one of these key biological cues will undergo drastic changes, while the other will remain fixed. This uncoupling can theoretically have drastic consequences on host-pathogen interactions. These poorly understood cues together with a changing climate by itself will challenge host populations that are adapted to pathogens under the historic and current climate regime. We will review adaptations of both host and pathogens to the extreme conditions at high latitudes and explore some potential consequences of rapid changes in the Arctic

    Evaluating a selective prevention programme for binge drinking among young adolescents: study protocol of a randomized controlled trial

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    Contains fulltext : 99319.pdf (publisher's version ) (Open Access)Background In comparison to other Europe countries, Dutch adolescents are at the top in drinking frequency and binge drinking. A total of 75% of the Dutch 12 to 16 year olds who drink alcohol also engage in binge drinking. A prevention programme called Preventure was developed in Canada to prevent adolescents from binge drinking. This article describes a study that aims to assess the effects of this selective school-based prevention programme in the Netherlands. Methods A randomized controlled trial is being conducted among 13 to 15-year-old adolescents in secondary schools. Schools were randomly assigned to the intervention and control conditions. The intervention condition consisted of two 90 minute group sessions, carried out at the participants' schools and provided by a qualified counsellor and a co-facilitator. The intervention targeted young adolescents who demonstrated personality risk for alcohol abuse. The group sessions were adapted to four personality profiles. The control condition received no further intervention above the standard substance use education sessions provided in the Dutch national curriculum. The primary outcomes will be the percentage reduction in binge drinking, weekly drinking and drinking-related problems after three specified time periods. A screening survey collected data by means of an Internet questionnaire. Students have completed, or will complete, a post-treatment survey after 2, 6, and 12 months, also by means of an online questionnaire. Discussion This study protocol presents the design and current implementation of a randomized controlled trial to evaluate the effectiveness of a selective alcohol prevention programme. We expect that a significantly lower number of adolescents will binge drink, drink weekly, and have drinking-related problems in the intervention condition compared to the control condition, as a result of this intervention.9 p

    Assessment of endogenous fibrinolysis in clinical using novel tests - Ready for clinical roll-out?

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    © The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.The occurrence of thrombotic complications, which can result in excess mortality and morbidity, represent an imbalance between the pro-thrombotic and fibrinolytic equilibrium.The mainstay treatment of these complications involves the use of antithrombotic agents but despite advances in pharmacotherapy, there remains a significant proportion of patients who continue to remain at risk.Endogenous fibrinolysis is a physiological counter-measure against lasting thrombosis and may be measured using several techniques to identify higher risk patients who may benefit from more aggressive pharmacotherapy. However, the assessment of the fibrinolytic systemis not yet accepted into routine clinical practice.In this review, we will revisit the different methods of assessing endogenous fibrinolysis (factorial assays, turbidimetric lysis assays, viscoelastic and the global thrombosis tests), including the strengths, limitations, correlation to clinical outcomes of each method and howwe might integrate the assessment of endogenous fibrinolysis into clinical practice in the future.Peer reviewedFinal Published versio

    Diseases and Causes of Death in European Bats: Dynamics in Disease Susceptibility and Infection Rates

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    Bats receive increasing attention in infectious disease studies, because of their well recognized status as reservoir species for various infectious agents. This is even more important, as bats with their capability of long distance dispersal and complex social structures are unique in the way microbes could be spread by these mammalian species. Nevertheless, infection studies in bats are predominantly limited to the identification of specific pathogens presenting a potential health threat to humans. But the impact of infectious agents on the individual host and their importance on bat mortality is largely unknown and has been neglected in most studies published to date.) were collected in different geographic regions in Germany. Most animals represented individual cases that have been incidentally found close to roosting sites or near human habitation in urban and urban-like environments. The bat carcasses were subjected to a post-mortem examination and investigated histo-pathologically, bacteriologically and virologically. Trauma and disease represented the most important causes of death in these bats. Comparative analysis of pathological findings and microbiological results show that microbial agents indeed have an impact on bats succumbing to infectious diseases, with fatal bacterial, viral and parasitic infections found in at least 12% of the bats investigated.Our data demonstrate the importance of diseases and infectious agents as cause of death in European bat species. The clear seasonal and individual variations in disease prevalence and infection rates indicate that maternity colonies are more susceptible to infectious agents, underlining the possible important role of host physiology, immunity and roosting behavior as risk factors for infection of bats
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