3,681 research outputs found

    Emergence of the GII-4 Norovirus Sydney2012 strain in England, winter 2012-2013.

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    Norovirus is the commonest cause of acute gastrointestinal disease and is the main aetiological agent of outbreaks of gastroenteritis, particularly in semi-closed environments. Norovirus infections in England typically peak between December and March each year. The most commonly detected norovirus strains belong to the genetically diverse genogroup-II genotype-4 (GII-4) genocluster and in the previous two norovirus winter seasons the majority of GII-4 strains in circulation worldwide have been genetically similar to the GII-4 strain New Orleans 1805/2009/USA. At the beginning of the 2012/13 season a genetically distinct GII-4 strain (Sydney 2012/NSW0514/2012/AU) was described which emerged worldwide during the winter of 2012/13. Here we describe the emergence of norovirus strains genetically related to Sydney2012 in England during the 2012/13 season to replace NewOrleans2009 strains as the most commonly detected variant of GII-4 norovirus in England. Furthermore, we demonstrate that whilst the emergence of Sydney2012 coincided with an early peak in the number of norovirus outbreaks, there was not an overall increase in norovirus activity compared to the previous season. Finally, we show that the Sydney2012 strain is associated with distinct genetic changes compared to the NewOrleans2009 strain, and these changes may have contributed to the emergence of the Sydney2012 strain

    What colour is penguin guano?

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    The identification and quantification of Antarctic Pygoscelis penguin colonies depends increasingly on recognition of the characteristic optical properties of guano deposits, but almost all knowledge of these properties until now has been compromised by resolution and atmospheric propagation effects. Here we present hyperspectral reflectance data in the range 350–2500 nm, collected in situ from fresh guano deposits in Pygoscelis penguin colonies on Signy Island, South Orkney Islands. The period of data collection included the transition from predominantly white guano to the pink coloration characteristic of a krill-rich diet. The main identifiable features in the spectra are a broad absorption feature centred around 550 nm, responsible for the pink coloration and identified with the pigment astaxanthin, as well as several water absorption features. Variations in these features are responsible for differentiation between spectra. From these results we propose two spectral indices suitable for use with satellite data, one of which responds to the presence of astaxanthin in the guano and the other to water. Our results do not allow us to differentiate between penguin species from their guano, but do suggest that the breeding phenology of Pygoscelis penguins could be determined from a time series of multispectral imagery.The fieldwork necessary for this work was supported by BAS through a Collaborative Gearing Scheme award CGS-97 to W.G. Rees and P.N. Trathan, and the ASD FieldSpec Pro was made available through an award (ref. 696.0614) from the UK NERC Field Spectroscopy Facility. We acknowledge with gratitude the support and companionship of the entire staff of the BAS research station at Signy, and especially of M. Jobson, the Base Commander. J.A. Brown is supported by a NERC PhD studentship NE/L501633/1

    Comparative quasi-static mechanical characterization of fresh and stored porcine trachea specimens

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    Abstract: Tissues of the upper airways of critically ill patients are particularly vulnerable to mechanical damage associated with the use of ventilators. Ventilation is known to disrupt the structural integrity of respiratory tissues and their function. This damage contributes to the vulnerability of these tissues to infection. We are currently developing tissue models of damage and infection to the upper airways. As part of our studies, we have compared how tissue storage conditions affect mechanical properties of excised respiratory tissues using a quasi-static platform. Data presented here show considerable differences in mechanical responses of stored specimens compared to freshly excised specimens. These data indicate that implementation of storage and maintenance procedures that minimize rapid degradation of tissue structure are essential for retaining the material properties in our tissue trauma models

    Polarised press reporting about HIV prevention: social representations of pre-exposure prophylaxis in the UK press

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    Pre-exposure prophylaxis is a novel biomedical HIV prevention option for individuals at high risk of HIV acquisition. Although pre-exposure prophylaxis has yielded encouraging results in various clinical trials, opponents argue that pre-exposure prophylaxis poses a number of risks to human health and to sexually transmitted infection prevention efforts. Using qualitative thematic analysis and social representation theory, this article explores coverage of pre-exposure prophylaxis in the UK print media between 2008 and 2015 in order to chart the emerging social representations of this novel HIV prevention strategy. The analysis revealed two competing social representations of pre-exposure prophylaxis: (1) as a positive development in the ‘battle’ against HIV (the hope representation) and (2) as a medical, social and psychological setback in this battle, particularly for gay/bisexual men (the risk representation). These social representations map onto the themes of pre-exposure prophylaxis as a superlatively positive development; pre-exposure prophylaxis as a weapon in the battle against HIV/AIDS; and risk, uncertainty and fear in relation to pre-exposure prophylaxis. The hope representation focuses on taking (individual and collective) responsibility, while the risk representation focuses on attributing (individual and collective) blame. The implications for policy and practice are discussed

    The appropriateness of core group interventions using presumptive periodic treatment among rural Zimbabwean women who exchange sex for gifts or money.

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    To map the characteristics of rural based sex workers in Zimbabwe with regard to demographics, mobility, behavior, HIV and sexually transmitted infection (STI) prevalence, to explore the appropriateness and feasibility of presumptive periodic treatment (PPT) for bacterial STIs as an HIV prevention intervention among these women, and to compare tolerability of 2 PPT regimens (1 g of azithromycin and 2 g of metronidazole+/-500 mg of ciprofloxacin). Five commercial farms and 2 mines in Mashonaland West, Zimbabwe. Three hundred sixty-three sex workers were recruited and completed a structured interviewer-administered questionnaire. Each participant had blood tested for antibody to HIV, herpes simplex virus 2 (HSV-2), and syphilis; urine tested for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG); and a vaginal swab tested for Trichomonas vaginalis (TV). Women were randomly assigned to receive a single dose of 1 of 2 PPT regimens and then followed to assess rates of side effects and reinfection. The overall prevalence of antibody to HIV was 55.7% (95% confidence interval [CI]: 50.6-60.9) and that of HSV-2 was 80.8% (95% CI: 76.7-84.9). The prevalence of CT and NG was low (CT=1.7%, 95% CI: 0.3-3.0); (NG=1.9%, 95% CI: 0.5-3.4), with a much higher prevalence of TV (TV=19.3%, 95% CI: 15.2-23.4). Prevalence of CT, NG, and TV was appreciably reduced 1 month after PPT but rose to pretreatment levels at the 2- and 3-month visits. The rate of moderate or severe side effects after PPT was low, but it was higher in the women who received ciprofloxacin in addition to azithromycin and metronidazole (P=0.007). It was feasible to access women who reported exchanging money or gifts for sex in rural communities, although many of these women engaged in sex work only infrequently. The prevalence of bacterial STIs was low, suggesting that PPT may not be an appropriate intervention in this setting. Rapid reinfection after PPT suggests that this needs to be given at monthly intervals to reduce prevalence of STIs

    Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System

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    The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species

    Medicaid Expenditures on Psychotropic Medications for Children in the Child Welfare System

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    Abstract Objective: Children in the child welfare system are the most expensive child population to insure for their mental health needs. The objective of this article is to estimate the amount of Medicaid expenditures incurred from the purchase of psychotropic drugs ? the primary drivers of mental health expenditures ? for these children. Methods: We linked a subsample of children interviewed in the first nationally representative survey of children coming into contact with U.S. child welfare agencies, the National Survey of Child and Adolescent Well-Being (NSCAW), to their Medicaid claims files obtained from the Medicaid Analytic Extract. Our data consist of children living in 14 states, and Medicaid claims for 4 years, adjusted to 2010 dollars. We compared expenditures on psychotropic medications in the NSCAW sample to a propensity score-matched comparison sample obtained from Medicaid files. Results: Children surveyed in NSCAW had over thrice the odds of any psychotropic drug use than the comparison sample. Each maltreated child increased Medicaid expenditures by between 237and237 and 840 per year, relative to comparison children also receiving medications. Increased expenditures on antidepressants and amphetamine-like stimulants were the primary drivers of these increased expenditures. On average, an African American child in NSCAW received 399lessexpenditurethanawhitechild,controllingforbehavioralproblemsandotherchildandregionalcharacteristics.ChildrenscoringintheclinicalrangeoftheChildBehaviorChecklistreceived,onaverage,399 less expenditure than a white child, controlling for behavioral problems and other child and regional characteristics. Children scoring in the clinical range of the Child Behavior Checklist received, on average, 853 increased expenditure on psychotropic drugs. Conclusion: Each child with child welfare involvement is likely to incur upwards of $1482 in psychotropic medication expenditures throughout his or her enrollment in Medicaid. Medicaid agencies should focus their cost-containment strategies on antidepressants and amphetamine-type stimulants, and expand use of instruments such as the Child Behavior Checklist to identify high-cost children. Both of these strategies can assist Medicaid agencies to better predict and plan for these expenditures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98497/1/cap%2E2011%2E0135.pd

    Increasing dominance of large lianas in Amazonian forests

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    Ecological orthodoxy suggests that old-growth forests should be close to dynamic equilibrium, but this view has been challenged by recent findings that neotropical forests are accumulating carbon and biomass, possibly in response to the increasing atmospheric concentrations of carbon dioxide. However, it is unclear whether the recent increase in tree biomass has been accompanied by a shift in community composition. Such changes could reduce or enhance the carbon storage potential of old-growth forests in the long term. Here we show that non-fragmented Amazon forests are experiencing a concerted increase in the density, basal area and mean size of woody climbing plants (lianas). Over the last two decades of the twentieth century the dominance of large lianas relative to trees has increased by 1.7–4.6% a year. Lianas enhance tree mortality and suppress tree growth, so their rapid increase implies that the tropical terrestrial carbon sink may shut down sooner than current models suggest. Predictions of future tropical carbon fluxes will need to account for the changing composition and dynamics of supposedly undisturbed forests

    Nocardia farcinica lung infection in a patient with cystic fibrosis: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Respiratory tract infections are the major causes of morbidity and mortality in patients with cystic fibrosis. <it>Nocardia </it>are rarely implicated in these infections and few reports of the involvement of this species are found in the literature.</p> <p>Case presentation</p> <p>We describe a case of lung infection followed by chronic colonization of trimethoprim and sulfamethoxazole resistant <it>Nocardia farcinica </it>in a patient with cystic fibrosis. The chronic colonization of this uncommon bacterium in patients with cystic fibrosis was proved using a newly developed real-time polymerase chain reaction assay, which indicates that this bacterium, despite treatment, is difficult to eradicate.</p> <p>Conclusion</p> <p>Our case report confirms that this organism can be recovered in persons with cystic fibrosis. Its eradication is necessary especially if the patient is to undergo lung transplantation.</p
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