1,721,037 research outputs found
Rapid syndromic molecular testing in pneumonia: the current landscape and future potential
No full textCommunity acquired pneumonia (CAP), hospital-acquired pneumonia (HAP) and ventilator associated pneumonia (VAP) are all associated with significant mortality and cause huge expense to health care services around the world. Early, appropriate antimicrobial therapy is crucial for effective treatment. Syndromic diagnostic testing using novel, rapid multiplexed molecular platforms represents a new opportunity for rapidly targeted antimicrobial therapy to improve patient outcomes and facilitate antibiotic stewardship. In this article we review the currently available testing platforms and discuss the potential benefits and pitfalls of rapid testing in pneumonia
The clinical impact of rapid molecular diagnostics in pneumonia
No full textPneumonia is a leading cause of mortality and morbidity worldwide. Novel syndromic molecular platforms have been developed which test for many different pneumonia causing organisms. These platforms have been shown to deliver reliable microbiological results in fraction of the time of conventional diagnostics with much greater sensitivity. Such investigations could revolutionise the care of patients with respiratory illness by influencing antibiotic prescribing and infection control decisions in near real-time. This thesis describes two clinical impact trials of molecular point-of-care testing (mPOCT) for respiratory pathogens in pneumonia.The Severe Acute Respiratory Illness Point-Of-Care (SARIPOC) trial was a randomised controlled trial which recruited adults with pneumonia in critical care. 200 patients were randomised to either standard clinical care or a molecular stewardship investigation including molecular testing with the Filmarray pneumonia panel, serum procalcitonin, and clinical infection advice. A contributory pathogen was identified in a 71% of mPOCT patients, compared to 51% of standard care patients. The median time to result was 1.7 hours for mPOCT and 66.7 hours for standard care. As a result of these increased, rapid detections, we demonstrated that 51% more patients in the mPOCT arm went onto optimal therapy for a microbiological result, with no observed difference in safety outcomes.The CoV-19 POC study was a non-randomised interventional trial, which recruited 500 adults presenting to secondary care with suspected SARS-CoV-2 infection. Patients were tested with the QIAstat-Dx respiratory SARS-CoV-2 panel within the first 24 hours of admission and compared to 555 contemporaneously identified control patients, who were admitted via the same admission pathways but were tested by standard laboratory PCR. Median time to results was quicker in the mPOCT tested group (by 19.6 hours), and as a result, patients spent almost 20.8 fewer hours in cohort assessment areas, where they could potentially be exposed to SARS-CoV-2 infection, before arriving in their definitive clinical area. These two trials demonstrate that mPOCT for respiratory pathogens are associated with reduced time to results compared to conventional diagnostics and with improvement in clinical care, including timely infection control decisions and in the appropriate use of antibiotics. Routine use of mPOCT for SARS-CoV-2 is now widespread in the UK. Further confirmatory trials are needed to before mPOCT for pneumonia can become standard practice in UK hospitals
SARS-CoV-2 has displaced other seasonal respiratory viruses: results from a prospective cohort study
No full textObjectives: The effect of SARS-CoV-2 on existing respiratory viruses in circulation and the overall burden of viral respiratory disease remains uncertain. Traditionally, severe viral respiratory disease disproportionally affects those with underlying chronic lung diseases. This study aimed to assess the impact of SARS-CoV-2 on the prevalence and clinical characteristics of respiratory virus disease in hospitalised adults. Methods: Data for this cohort study were from hospitalised adults who had multiplex PCR testing for respiratory viruses over several seasons in Hampshire, UK. Respiratory virus detection during the first epidemic peak of SARS-CoV-2 was compared to detection during the same time period across previous years. Results: 856 patients had multiplex PCR for respiratory viruses between March and May over 5 years. Before 2020, a non-SARS-CoV-2 virus was detected in 54% patients (202/371) compared to 4.1% (20/485) in 2020 (p < 0.0001). SARS-CoV-2 was associated with asthma or COPD exacerbations in a smaller proportion of infected patients compared to other viruses (1.0% vs 37%, p < 0.0001). Conclusions: The emergence of SARS-CoV-2 was associated with substantial reductions in the circulation of seasonal respiratory viruses and large differences in the characteristics of viral-associated disease, including illness in a greater proportion of patients without underlying lung disease.</p
Physical distancing in schools for SARS-CoV-2 and the resurgence of rhinovirus
No full textChildren have greater difficulty adhering to physical distancing rules but are believed to transmit the virus less efficiently than adults. Rhinoviruses normally circulate year-round with seasonal peaks in spring and autumn and are transmitted in largely the same manner as SARS-CoV-2. Children are the main drivers of transmission of rhinovirus, with subsequent transmission to adults associated with exacerbations of airways disease and hospitalisations.2In Southampton, UK, we tested adult medical patients admitted to hospital for a wide range of respiratory viruses, including SARS-CoV-2, from the height of the pandemic. We compared the rate of respiratory virus detection in 2020 with the same period in 2019. Around 2 weeks after the concurrent re-opening of state primary and secondary schools in early September, there was a sharp increase in the number of detections similar to that seen in 2019. Our data support previous reports that children are a major reservoir for rhinovirus infection, and a key driver of transmission to adults
Robust split-step Fourier methods for simulating the propagation of ultra-short pulses in single- and two-mode optical communication fibers
No full textExtensions of the split-step Fourier method (SSFM) for Schrodinger-type pulse propagation equations for simulating femto-second pulses in single- and two-mode optical communication fibers are developed and tested for Gaussian pulses. The core idea of the proposed numerical methods is to adopt an operator splitting approach, in which the nonlinear sub-operator, consisting of Kerr nonlinearity, the self-steepening and stimulated Raman scattering terms, is reformulated using Madelung transformation into a quasilinear first-order system of signal intensity and phase. A second-order accurate upwind numerical method is derived rigorously for the resulting system in the single-mode case; a straightforward extension of this method is used to approximate the four-dimensional system resulting from the nonlinearities of the chosen two-mode model. Benchmark SSFM computations of prototypical ultra-fast communication pulses in idealized single- and two-mode fibers with homogeneous and alternating dispersion parameters and also high nonlinearity demonstrate the reliable convergence behavior and robustness of the proposed approach
Re: 'syndromic panels or “panel syndrome”? A perspective through the lens of respiratory-tract infections' by Zanella et al
No full textA review of novel technologies and techniques associated with identification of bloodstream infection etiologies and rapid antimicrobial genotypic and quantitative phenotypic determination
No full textIntroduction: The antimicrobial aspect of management of patients with blood stream infections (BSI) and sepsis is time critical. In an era of increasing antimicrobial resistance, rapid detection and identification of bacteria with antimicrobial susceptibility is crucial to direct therapy early in the course of illness. Molecular techniques offer a potential solution to this. Areas covered: In the present review the authors have discussed a number of novel solutions utilizing a variety of molecular techniques for pathogen detection, identification and antimicrobial susceptibility. The review is not designed to be an exhaustive literature review covering all diagnostic solutions ever developed, instead the authors have focused on what they have had experience using, evaluating or currently view as new and exciting with potential to revolutionize BSI diagnosis. The authors searched PubMed (Medline) and Google Scholar with terms: BSI, Bacteraemia, Candidaemia, Diagnostics, AST, Rapid, AMR, Novel and Blood Culture. The authors attended recent clinical microbiology technology congresses. Expert commentary: There are multiple exciting novel technologies at differing stages of development with potential to revolutionize diagnosis of BSI. More work is needed as well as a standardized assessment of different platforms in order to better understand the clinical and financial impacts these will have in clinical microbiology laboratories.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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