Comparative age distribution of influenza morbidity and mortality during seasonal influenza epidemics and the 2009 H1N1 pandemic

<p>Abstract</p> <p>Background</p> <p>Several studies have shown a relatively high mortality rate among young people infected by the 2009 pandemic influenza A (H1N1) virus. Here we compared the age distributions of morbidity and mortality during two seasonal influenza epidemics (H1N1 and H3N2) in France and the United States with those of the 2009 H1N1 pandemic waves in the same countries.</p> <p>Methods</p> <p>Age-standardized ratios were used to compare the age distribution of morbidity and mortality due to influenza between the two countries and across the different years. Non parametric analysis of variance was used to compare these ratios between epidemic and pandemic influenza.</p> <p>Results</p> <p>Age distribution of morbidity was similar between the 2009 pandemic and seasonal epidemics due to H1N1 (p = 0.72) and H3N2 viruses (p = 0.68). In contrast, the proportion of under-60s among influenza deaths was markedly higher during the 2009 pandemic (peak <20 years) than during the seasonal epidemics (respectively p = 0.007 and p = 0.0008).</p> <p>Conclusions</p> <p>Young age was a principal mortality risk factor due to the 2009 H1N1 pandemic.</p

Restoration of Videos Degraded by Local Isoplanatism Effects in the Near-Infrared Domain

When observing a scene horizontally at a long distance in the near-infrared domain, degradations due to atmospheric turbulence often occur. In our previous work, we presented two hybrid methods to restore videos degraded by such local perturbations. These restoration algorithms take advantages of a space-time Wiener filter and a space-time regularization by the Laplacian operator. Wiener and Laplacian regularization results are mixed differently depending on the distance between the current pixel and the nearest edge point. It was shown that a gradation between Wiener and Laplacian areas improves results quality, so that only the algorithm using a gradation will be used in this article. In spite of a significant improvement in the obtained images quality, our restoration results greatly depend on the segmentation image used in the video processing. We then propose a method to select automatically the best segmentation image

Surgical Mask to Prevent Influenza Transmission in Households: A Cluster Randomized Trial

Facemasks and respirators have been stockpiled during pandemic preparedness. However, data on their effectiveness for limiting transmission are scarce. We evaluated the effectiveness of facemask use by index cases for limiting influenza transmission by large droplets produced during coughing in households.A cluster randomized intervention trial was conducted in France during the 2008-2009 influenza season. Households were recruited during a medical visit of a household member with a positive rapid influenza A test and symptoms lasting less than 48 hours. Households were randomized either to the mask or control group for 7 days. In the intervention arm, the index case had to wear a surgical mask from the medical visit and for a period of 5 days. The trial was initially intended to include 372 households but was prematurely interrupted after the inclusion of 105 households (306 contacts) following the advice of an independent steering committee. We used generalized estimating equations to test the association between the intervention and the proportion of household contacts who developed an influenza-like illness during the 7 days following the inclusion. Influenza-like illness was reported in 24/148 (16.2%) of the contacts in the intervention arm and in 25/158 (15.8%) of the contacts in the control arm and the difference between arms was 0.40% (95%CI: -10% to 11%, P = 1.00). We observed a good adherence to the intervention. In various sensitivity analyses, we did not identify any trend in the results suggesting effectiveness of facemasks.This study should be interpreted with caution since the lack of statistical power prevents us to draw formal conclusion regarding effectiveness of facemasks in the context of a seasonal epidemic.clinicaltrials.gov NCT00774774

Evolutionary Dynamics of Human Toll-Like Receptors and Their Different Contributions to Host Defense

Infectious diseases have been paramount among the threats to health and survival throughout human evolutionary history. Natural selection is therefore expected to act strongly on host defense genes, particularly on innate immunity genes whose products mediate the direct interaction between the host and the microbial environment. In insects and mammals, the Toll-like receptors (TLRs) appear to play a major role in initiating innate immune responses against microbes. In humans, however, it has been speculated that the set of TLRs could be redundant for protective immunity. We investigated how natural selection has acted upon human TLRs, as an approach to assess their level of biological redundancy. We sequenced the ten human TLRs in a panel of 158 individuals from various populations worldwide and found that the intracellular TLRs—activated by nucleic acids and particularly specialized in viral recognition—have evolved under strong purifying selection, indicating their essential non-redundant role in host survival. Conversely, the selective constraints on the TLRs expressed on the cell surface—activated by compounds other than nucleic acids—have been much more relaxed, with higher rates of damaging nonsynonymous and stop mutations tolerated, suggesting their higher redundancy. Finally, we tested whether TLRs have experienced spatially-varying selection in human populations and found that the region encompassing TLR10-TLR1-TLR6 has been the target of recent positive selection among non-Africans. Our findings indicate that the different TLRs differ in their immunological redundancy, reflecting their distinct contributions to host defense. The insights gained in this study foster new hypotheses to be tested in clinical and epidemiological genetics of infectious disease

Evaluer l'immunité de population contre la grippe (observation et intervention épidémiologiques)

PARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Étude de la turbulence atmosphérique en vision horizontale lointaine et restauration de séquences dégradées dans le visible et l'infrarouge

La turbulence atmosphérique dégrade fortement les acquisitions d'images sur de longues distances. Les propriétés de la turbulence et ses effets en imagerie sont tout d'abord rappelés. Plusieurs algorithmes de simulation sont ensuite exposés, permettant de générer des images ou séquences dégradées, selon le type de turbulence désiré. Quelques méthodes classiques de restauration sont testées sur des images, ne donnant des résultats satisfaisants que pour une faible perturbation. Une méthode spatio-temporelle de traitement est ensuite testée sur des séquences. Les résultats sont satisfaisants pour la visualisation, mais trop bruités pour une application numérique. Cette méthode de restauration est alors adaptée à une régularisation pour atténuer le bruit. L'approche finale de restauration proposée consiste à fusionner les deux résultats de traitement de séquence afin d'obtenir une image restaurée utilisable à la fois pour la visualisation et une application numérique.Atmospheric turbulence strongly degrades image acquisitions on long distances. Turbulence properties and its effects on imagery are first recalled. Several simulation algorithms are then exposed, allowing to generate degraded images or sequences, according to the desired kind of turbulence. Some classical restoration methods are tested on images, giving satisfactory results only for a weak perturbation. A space-time processing method is tested on sequences. Results are satisfactory for visualization, but too much noisy for a digital application. This restoration method is adapted to a regularization to attenuate noise. The final suggested approach of restoration consists in amalgamating the two last results in order to obtain a restored image usable at the same time for visualization and a digital application.DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

Viral resistance may limit the benefit of neuraminidase inhibitors therapy during an influenza pandemic

International audienc

Les surfaçages manuels et mécanisés

Les concepts de traitement des maladies parodontales ont beaucoup évolué vers une optimisation de l'efficacité et des traitements étiologiques. Les objectifs actuels sont : la désorganisation du biofilm sous-gingival, l'élimination des dépôts tartriques et la décontamination des surfaces radiculaires. Ceci permet de maîtriser l'inflammation et l'infection, et d'améliorer la cicatrisation. Nous évaluons les différentes techniques ultrasonores permettant l'optimisation de ces objectifs à un moindre coût biologique. Une instrumentation mécanisée sonore, puis ultrasonore a remplacé une instrumentation manuelle agressive et nécessitant un emploi rigoureux. L'évolution technique permet une bonne adaptation de ces instruments à la morphologie des surfaces à traiter et une décontamination maximale des poches parodontales. Les résultats cliniques semblent plus performants avec une technique plus efficace et précise.NANTES-BU Médecine pharmacie (441092101) / SudocPARIS-BIUM (751062103) / SudocNANTES-Bib.Odontologie (441092219) / SudocSudocFranceF