Laboratory data as a quality indicator of health-care-associated infections in England.

Routine diagnostic laboratory results, e.g. numbers of meticillin-resistant Staphylococcus aureus (MRSA) bacteraemias, have been used as health-care-associated infection quality indicators for decades. The English health-care-associated infection quality indicator system was one of the earliest in the world to mandate the collection and public reporting of such data and has been associated with a reduction of MRSA bacteraemias and Clostridium difficile infections but has shown mixed results for other infections. Diagnostic laboratory data vary greatly between hospitals depending not only on the underlying frequency of the infection of interest, but on the case mix, numbers of samples processed and laboratory factors, which limits benchmarking. Further, over-reliance on laboratory reports has led to unintended negative consequences in England. So, while acknowledging the successes of the English system, the authors believe that it should be appraised in light of the goals of quality of care, patient safety, fairness and providing meaningful data, and alternative healthcare-associated infection quality indicator measurements considered

The Binet-Legendre Metric in Finsler Geometry

For every Finsler metric $F$ we associate a Riemannian metric $g_F$ (called the Binet-Legendre metric). The transformation $F \mapsto g_F$ is $C^0$-stable and has good smoothness properties, in contrast to previous constructions. The Riemannian metric $g_F$ also behaves nicely under conformal or bilipshitz deformation of the Finsler metric $F$. These properties makes it a powerful tool in Finsler geometry and we illustrate that by solving a number of named Finslerian geometric problems. We also generalize and give new and shorter proofs of a number of known results. In particular we answer a question of M. Matsumoto about local conformal mapping between two Minkowski spaces, we describe all possible conformal self maps and all self similarities on a Finsler manifold. We also classify all compact conformally flat Finsler manifolds, solve a conjecture of S. Deng and Z. Hou on the Berwaldian character of locally symmetric Finsler spaces, and extend the classic result of H.C. Wang about the maximal dimension of the isometry groups of Finsler manifolds to manifolds of all dimensions. Most proofs in this paper go along the following scheme: using the correspondence $F \mapsto g_F$we reduce the Finslerian problem to a similar problem for the Binet-Legendre metric, which is easier and is already solved in most cases we consider. The solution of the Riemannian problem provides us with the additional information that helps to solve the initial Finslerian problem. Our methods apply even in the absence of the strong convexity assumption usually assumed in Finsler geometry. The smoothness hypothesis can also be replaced by that of partial smoothness, a notion we introduce in the paper. Our results apply therefore to a vast class of Finsler metrics not usually considered in the Finsler literature.Comment: 33 pages, 5 figures. This version is slightly reduced fron versions 1 and 2. The paper has been published in Geometry & Topolog

The predictive value of quantitative nucleic acid amplification detection of Clostridium difficile toxin gene for faecal sample toxin status and patient outcome.

BACKGROUND: Laboratory diagnosis of Clostridium difficile infection (CDI) remains unsettled, despite updated guidelines. We investigated the potential utility of quantitative data from a nucleic acid amplification test (NAAT) for C. difficile toxin gene (tg) for patient management. METHODS: Using data from the largest ever C. difficile diagnostic study (8853 diarrhoeal samples from 7335 patients), we determined the predicative value of C. difficile tgNAAT (Cepheid Xpert C.diff) low cycle threshold (CT) value for patient toxin positive status, CDI severity, mortality and CDI recurrence. Reference methods for CDI diagnosis were cytotoxicity assay (CTA) and cytotoxigenic culture (CTC). RESULTS: Of 1281 tgNAAT positive faecal samples, 713 and 917 were CTA and CTC positive, respectively. The median tgNAAT CT for patients who died was 25.5 vs 27.5 for survivors (p = 0.021); for toxin-positivity was 24.9 vs 31.6 for toxin-negative samples (p<0.001) and for patients with a recurrence episode was 25.6 vs 27.3 for those who did not have a recurrent episode (p = 0.111). Following optimal cut-off determination, low CT was defined as ≤25 and was significantly associated with a toxin-positive result (P<0.001, positive predictive value 83.9%), presence of PCR-ribotype 027 (P = 0.025), and mortality (P = 0.032). Recurrence was not associated with low CT (p 0.111). CONCLUSIONS: Low tgNAAT CT could indicate CTA positive patients, have more severe infection, increased risk of mortality and possibly recurrence. Although, the limited specificity of tgNAAT means it cannot be used as a standalone test, it could augment a more timely diagnosis, and optimise management of these at-risk patients

PCR for the detection of pathogens in neonatal early onset sepsis.

BACKGROUND: A large proportion of neonates are treated for presumed bacterial sepsis with broad spectrum antibiotics even though their blood cultures subsequently show no growth. This study aimed to investigate PCR-based methods to identify pathogens not detected by conventional culture. METHODS: Whole blood samples of 208 neonates with suspected early onset sepsis were tested using a panel of multiplexed bacterial PCRs targeting Streptococcus pneumoniae, Streptococcus agalactiae (GBS), Staphylococcus aureus, Streptococcus pyogenes (GAS), Enterobacteriaceae, Enterococcus faecalis, Enterococcus faecium, Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis and Mycoplasma genitalium, a 16S rRNA gene broad-range PCR and a multiplexed PCR for Candida spp. RESULTS: Two-hundred and eight samples were processed. In five of those samples, organisms were detected by conventional culture; all of those were also identified by PCR. PCR detected bacteria in 91 (45%) of the 203 samples that did not show bacterial growth in culture. S. aureus, Enterobacteriaceae and S. pneumoniae were the most frequently detected pathogens. A higher bacterial load detected by PCR was correlated positively with the number of clinical signs at presentation. CONCLUSION: Real-time PCR has the potential to be a valuable additional tool for the diagnosis of neonatal sepsis

Maladie de Lyme, syndrome autistique et traitement antibiotique : une réflexion à partir d'un cas

International audienceFollowing an overview of the definition of autism and Lyme disease, a clinical case will be presented of a young subject (aged 14 years and a half) diagnosed with autism, and characterized by a typical development in the first year of life, followed by a general deterioration of abilities shortly after diagnosis of the onset of Lyme disease. The subject presented positive reactivity for Mycoplasma Pneumoniae. According to recent studies, misdiagnosis of initial symptoms of Lyme disease and delayed treatment can lead to persistent interactive coinfections in the organism which may result in chronic pathologies. Thus, a link could exist between a chronic infectionwith Mycoplasma Pneumoniae and an atypical symptomology similar to autism. So the hypothesis proposed is that there may be a correlation between Lyme disease and autism and that long-term antibiotic therapy may be an effective treatment. Following a clinical presentation of the history of this young patient, the evolution of the subject's symptomology and behavior during one year of antibiotic therapy will be described.A la suite d'un rappel de la définition de l'autisme infantile et de la maladie de Lyme, un cas clinique sera développé. Il s'agit d'un jeune patient avec autisme âgé de 14 ans et demi, caractérisé par un développement initial typique pendant sa première année puis par une dégradation générale de ses aptitudes peu après avoir été atteint de la maladie de Lyme. A la suite d'une présentation sous la forme d'une vignette clinique, nous aborderons l'évolution de la symptomatologie et du comportement de ce jeune pendant un an d'antibiothérapie. Cette présentation de cas permettra finalement d'interroger la définition de l'autisme, son étiologie et la validité du diagnostic établi initialement pour ce patient

Minimum Eccentricity Shortest Path Problem: an Approximation Algorithm and Relation with the k-Laminarity Problem

The Minimum Eccentricity Shortest Path (MESP) Problem consists in determining a shortest path (a path whose length is the distance between its extremities) of minimum eccentricity in a graph. It was introduced by Dragan and Leitert [9] who described a linear-time algorithm which is an 8-approximation of the problem. In this paper, we study deeper the double-BFS procedure used in that algorithm and extend it to obtain a linear-time 3-approximation algorithm. We moreover study the link between the MESP problem and the notion of laminarity, introduced by Völkel et al [12], corresponding to its restriction to a diameter (i.e. a shortest path of maximum length), and show tight bounds between MESP and laminarity parameters