423 research outputs found

    Influenza activity in Europe during eight seasons (1999–2007): an evaluation of the indicators used to measure activity and an assessment of the timing, length and course of peak activity (spread) across Europe

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    <p>Abstract</p> <p>Background</p> <p>The European Influenza Surveillance Scheme (EISS) has collected clinical and virological data on influenza since 1996 in an increasing number of countries. The EISS dataset was used to characterise important epidemiological features of influenza activity in Europe during eight winters (1999–2007). The following questions were addressed: 1) are the sentinel clinical reports a good measure of influenza activity? 2) how long is a typical influenza season in Europe? 3) is there a west-east and/or south-north course of peak activity ('spread') of influenza in Europe?</p> <p>Methods</p> <p>Influenza activity was measured by collecting data from sentinel general practitioners (GPs) and reports by national reference laboratories. The sentinel reports were first evaluated by comparing them to the laboratory reports and were then used to assess the timing and spread of influenza activity across Europe during eight seasons.</p> <p>Results</p> <p>We found a good match between the clinical sentinel data and laboratory reports of influenza collected by sentinel physicians (overall match of 72% for +/- 1 week difference). We also found a moderate to good match between the clinical sentinel data and laboratory reports of influenza from non-sentinel sources (overall match of 60% for +/- 1 week). There were no statistically significant differences between countries using ILI (influenza-like illness) or ARI (acute respiratory disease) as case definition. When looking at the peak-weeks of clinical activity, the average length of an influenza season in Europe was 15.6 weeks (median 15 weeks; range 12–19 weeks). Plotting the peak weeks of clinical influenza activity reported by sentinel GPs against the longitude or latitude of each country indicated that there was a west-east spread of peak activity (spread) of influenza across Europe in four winters (2001–2002, 2002–2003, 2003–2004 and 2004–2005) and a south-north spread in three winters (2001–2002, 2004–2005 and 2006–2007).</p> <p>Conclusion</p> <p>We found that: 1) the clinical data reported by sentinel physicians is a valid indicator of influenza activity; 2) the length of influenza activity across the whole of Europe was surprisingly long, ranging from 12–19 weeks; 3) in 4 out of the 8 seasons, there was a west-east spread of influenza, in 3 seasons a south-north spread; not associated with type of dominant virus in those seasons.</p

    Oseltamivir-resistant influenza A(H1N1)pdm09 virus in Dutch travellers returning from Spain, August 2012

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    Two Dutch travellers were infected with oseltamivirresistant influenza A(H1N1)pdm09 viruses with an H275Y neuraminidase substitution in early August 2012. Both cases were probably infected during separate holidays at the Catalonian coast (Spain). No epidemiological connection between the two cases was found, and neither of them was treated with oseltamivir before specimen collection. Genetic analysis of the neuraminidase gene revealed the presence of previously described permissive mutations that may increase the likelihood of such strains emerging and spreading widely

    Oxygenated versus non-oxygenated flush out and storage of donor livers:An experimental study

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    Background: During donor organ procurement and subsequent static cold storage (SCS), hepatic adenosine triphosphate (ATP) levels are progressively depleted, which contributes to ischemia-reperfusion injury (IRI). We sought to investigate a simple approach to prevent ATP depletion and IRI using a porcine donation after circulatory death (DCD) liver reperfusion model. Methods: After 30 min warm ischemia, porcine livers were flushed via the portal vein with cold (4 degrees C) non-oxygenated University of Wisconsin (UW) preservation solution (n = 6, control group) or with oxygenated UW (n = 6, OxyFlush group). Livers were then subjected to 4 h SCS in non-oxygenated (control) or oxygenated (OxyFlush) UW, followed by 4 h normothermic reperfusion using whole blood. Hepatic ATP levels were compared, and hepatobiliary function and injury were assessed. Results: At the end of SCS, ATP was higher in the OxyFlush group compared to controls (delta ATP of +0.26 vs. -0.68 mu mol/g protein, p = 0.04). All livers produced bile and metabolized lactate, and there were no differences between the groups. Grafts in the OxyFlush group had lower blood glucose levels after reperfusion (p = 0.04). Biliary pH, glucose and bicarbonate were not different between the groups. Injury markers including liver transaminases, lactate dehydrogenase, malondialdehyde, cell-free DNA and flavin mononucleotide in the SCS solution and during reperfusion were also similar. Histological assessment of the parenchyma and bile ducts did not reveal differences between the groups. Conclusion: Oxygenated flush out and storage of DCD porcine livers prevents ATP depletion during ischemia, but this does not seem sufficient to mitigate early signs of IRI

    Influenza vaccine effectiveness estimates in the Dutch population from 2003 to 2014:The test-negative design case-control study with different control groups

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    Information about influenza vaccine effectiveness (IVE) is important for vaccine strain selection and immunization policy decisions. The test-negative design (TND) case-control study is commonly used to obtain IVE estimates. However, the definition of the control patients may influence IVE estimates. We have conducted a TND study using the Dutch Sentinel Practices of NIVEL Primary Care Database which includes data from patients who consulted the General Practitioner (GP) for an episode of acute influenza-like illness (ILI) or acute respiratory infection (ARI) with known influenza vaccination status. Cases were patients tested positive for influenza virus. Controls were grouped into those who tested (1) negative for influenza virus (all influenza negative), (2) negative for influenza virus, but positive for respiratory syncytial virus, rhinovirus or enterovirus (non-influenza virus positive), and (3) negative for these four viruses (pan-negative). We estimated the IVE over all epidemic seasons from 2003/2004 through 2013/2014, pooled IVE for influenza vaccine partial/full matched and mismatched seasons and the individual seasons using generalized linear mixed-effect and multiple logistic regression models. The overall IVE adjusted for age, GP ILI/ARI diagnosis, chronic disease and respiratory allergy was 35% (95% CI: 15-48), 64% (95% CI: 49-75) and 21% (95% CI: -1 to 39) for all influenza negative, non-influenza virus positive and pan-negative controls, respectively. In both the main and subgroup analyses IVE estimates were the highest using non-influenza virus positive controls, likely due to limiting inclusion of controls without laboratory-confirmation of a virus causing the respiratory disease

    Influenza A(H1N1) Oseltamivir Resistant Viruses in the Netherlands During the Winter 2007/2008

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    Background: Antiviral susceptibility surveillance in the Netherlands was intensified after the first reports about the emergence of influenza A(H1N1) oseltamivir resistant viruses in Norway in January, 2008. Methods: Within the existing influenza surveillance an additional questionnaire study was performed to retrospectively assess possible risk factors and establish clinical outcome of all patients with influenza virus A(H1N1) positive specimens. To discriminate resistant and sensitive viruses, fifty percent inhibitory concentrations for the neuramidase inhibitors oseltamivir and zanamivir were determined in a neuraminidase inhibition assay. Mutations previously associated with resistance to neuramidase inhibitors and M2 blockers (amantadine and rimantadine) were searched for by nucleotide sequencing of neuraminidase and M2 genes respectively. Results: Among 171 patients infected with A(H1N1) viruses an overall prevalence of oseltamivi resistance of 27% (95% CI: 20-34%) was found. None of influenza A(H1N1) oseltamivir resistant viruses tested was resistant against amantadine or zanamivir. Patient characteristics, underlying conditions, influenza vaccination, symptoms, complications, and exposure to oseltamivir and other antivirals did not differ significantly between patients infected with resistant and sensitive A(H1N1) viruses. Conclusion: In 2007/2008 a large proportion of influenza A(H1N1) viruses resistant to oseltamivir was detected. There were no clinical differences between patients infected with resistant and sensitive A(H1N1) viruses. Continuous monitoring of the antiviral drug sensitivity profile of influenza viruses is justified, preferably using the existing sentinel surveillance, however, complemented with data from the more severe end of the clinical spectrum. In order to act timely on emergencies of public health importance we suggest setting up a surveillance system that can guarantee rapid access to the latter. (aut. ref.

    Comparison of seven commercial RT-PCR diagnostic kits for COVID-19

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    The final months of 2019 witnessed the emergence of a novel coronavirus in the human population. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has since spread across the globe and is posing a major burden on society. Measures taken to reduce its spread critically depend on timely and accurate identification of virus-infected individuals by the most sensitive and specific method available, i.e. real-time reverse transcriptase PCR (RT-PCR). Many commercial kits have recently become available, but their performance has not yet been independently assessed. The aim of this study was to compare basic analytical and clinical performance of selected RT-PCR kits from seven different manufacturers (Altona Diagnostics, BGI, CerTest Biotec, KH Medical, PrimerDesign, R-Biopharm AG, and Seegene). We used serial dilutions of viral RNA to establish PCR efficiency and estimate the 95 % limit of detection (LOD95). Furthermore, we ran a panel of SARS-CoV-2-positive clinical samples (n = 13) for a preliminary evaluation of clinical sensitivity. Finally, we used clinical samples positive for non-coronavirus respiratory viral infections (n = 6) and a panel of RNA from related human coronaviruses to evaluate assay specificity. PCR efficiency was ≥96 % for all assays and the estimated LOD95 varied within a 6-fold range. Using clinical samples, we observed some variations in detection rate between kits. Importantly, none of the assays showed cross-reactivity with other respiratory (corona)viruses, except as expected for the SARS-CoV-1 E-gene. We conclude that all RT-PCR kits assessed in this study may be used for routine diagnostics of COVID-19 in patients by experienced molecular diagnostic laboratories

    Cardiovascular Fitness and Executive Functioning in Primary School-aged Children

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    Previous research in children has shown that higher cardiovascular fitness is related to better executive functioning. However, the available literature is hampered by methodological limitations. The present study investigates the relationship between cardiovascular fitness and executive functioning in a large sample of healthy children (N = 814). Cardiovascular fitness was assessed with estimated VO2Max from 20 m Shuttle Run Test performance. Executive functioning was assessed using a set of computerized neurocognitive tasks aimed at executive functions (working memory, motor inhibition, interference control) and lower-level neurocognitive functions (information processing and attention). Dependent measures derived from the neurocognitive tests were subjected to principal component analysis. Mixed model analyses tested the relation between cardiovascular fitness and neurocognitive functioning components. Results showed that children with higher cardiovascular fitness performed better on the neurocognitive function components Information Processing and Control, Visuospatial Working Memory and Attention Efficiency. The following measures contained in these components contributed to the observed relations: information processing measures, visuospatial working memory, and speed of alerting attention. No relationship was found between cardiovascular fitness and the other components: Verbal Working Memory, Attention Accuracy, and Interference Control. The present study suggests that there is a relationship between cardiovascular fitness and a specific set of executive functions and lower level neurocognitive functions. These findings highlight the importance of cardiovascular fitness for the overall health of school-aged children

    Restoration of Bile Duct Injury of Donor Livers During Ex Situ Normothermic Machine Perfusion

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    BACKGROUND: End-ischemic ex situ normothermic machine perfusion (NMP) enables assessment of donor livers prior to transplantation. The objective of this study was to provide support for bile composition as a marker of biliary viability and to investigate whether bile ducts of high-risk human donor livers already undergo repair during NMP.METHODS: Forty-two livers that were initially declined for transplantation were included in our NMP clinical trial. After NMP, livers were either secondary declined (n = 17) or accepted for transplantation (n = 25) based on the chemical composition of bile and perfusate samples. Bile duct biopsies were taken before and after NMP and assessed using an established histological injury severity scoring system and a comprehensive immunohistochemical assessment focusing on peribiliary glands (PBGs), vascular damage, and regeneration.RESULTS: Bile ducts of livers that were transplanted after viability testing during NMP showed better preservation of PBGs, (micro)vasculature, and increased cholangiocyte proliferation, compared with declined livers. Biliary bicarbonate, glucose, and pH were confirmed as accurate biomarkers of bile duct vitality. In addition, we found evidence of PBG-based progenitor cell differentiation toward mature cholangiocytes during NMP.CONCLUSIONS: Favorable bile chemistry during NMP correlates well with better-preserved biliary microvasculature and PBGs, with a preserved capacity for biliary regeneration. During NMP, biliary tree progenitor cells start to differentiate toward mature cholangiocytes, facilitating restoration of the ischemically damaged surface epithelium.</p

    Case of seasonal reassortant A(H1N2) influenza virus infection, the Netherlands, March 2018.

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    A seasonal reassortant A(H1N2) influenza virus harbouring genome segments from seasonal influenza viruses A(H1N1)pdm09 (HA and NS) and A(H3N2) (PB2, PB1, PA, NP, NA and M) was identified in March 2018 in a 19-months-old patient with influenza-like illness (ILI) who presented to a general practitioner participating in the routine sentinel surveillance of ILI in the Netherlands. The patient recovered fully. Further epidemiological and virological investigation did not reveal additional cases
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