La prevención y lucha frente a una posible pandemia de gripe aviar

La prevención y lucha frente a una posible pandemia de gripe aviar

Using surveillance data to estimate pandemic vaccine effectiveness against laboratory confirmed influenza A(H1N1)2009 infection : two case-control studies, Spain, season 2009-2010

Background: Physicians of the Spanish Influenza Sentinel Surveillance System report and systematically swab patients attended to their practices for influenza-like illness (ILI). Within the surveillance system, some Spanish regions also participated in an observational study aiming at estimating influenza vaccine effectiveness (cycEVA study). During the season 2009-2010, we estimated pandemic influenza vaccine effectiveness using both the influenza surveillance data and the cycEVA study. Methods: We conducted two case-control studies using the test-negative design, between weeks 48/2009 and 8/2010 of the pandemic season. The surveillance-based study included all swabbed patients in the sentinel surveillance system. The cycEVA study included swabbed patients from seven Spanish regions. Cases were laboratory-confirmed pandemic influenza A(H1N1)2009. Controls were ILI patients testing negative for any type of influenza. Variables collected in both studies included demographic data, vaccination status, laboratory results, chronic conditions, and pregnancy. Additionally, cycEVA questionnaire collected data on previous influenza vaccination, smoking, functional status, hospitalisations, visits to the general practitioners, and obesity. We used logistic regression to calculate adjusted odds ratios (OR), computing pandemic influenza vaccine effectiveness as (1-OR *100. Results: We included 331 cases and 995 controls in the surveillance-based study and 85 cases and 351 controls in the cycEVA study. We detected nine (2.7%) and two (2.4%) vaccine failures in the surveillance-based and cycEVA studies, respectively. Adjusting for variables collected in surveillance database and swabbing month, pandemic influenza vaccine effectiveness was 62% (95% confidence interval (CI): -5; 87). The cycEVA vaccine effectiveness was 64% (95%CI: -225; 96) when adjusting for common variables with the surveillance system and 75% (95%CI: -293; 98) adjusting for all variables collected. Conclusion: Point estimates of the pandemic influenza vaccine effectiveness suggested a protective effect of the pandemic vaccine against laboratory-confirmed influenza A(H1N1)2009 in the season 2009-2010. Both studies were limited by the low vaccine coverage and the late start of the vaccination campaign. Routine influenza surveillance provides reliable estimates and could be used for influenza vaccine effectiveness studies in future seasons taken into account the surveillance system limitations

Homérica: estudiar y vivir el mundo griego II

Depto. de Filología ClásicaFac. de FilologíaFALSEsubmitte

Characterization in vitro and in vivo of a pandemic H1N1 influenza virus from a fatal case

Pandemic 2009 H1N1 (pH1N1) influenza viruses caused mild symptoms in most infected patients. However, a greater rate of severe disease was observed in healthy young adults and children without co-morbid conditions. Here we tested whether influenza strains displaying differential virulence could be present among circulating pH1N1 viruses. The biological properties and the genotype of viruses isolated from a patient showing mild disease (M) or from a fatal case (F), both without known co-morbid conditions were compared in vitro and in vivo. The F virus presented faster growth kinetics and stronger induction of cytokines than M virus in human alveolar lung epithelial cells. In the murine model in vivo, the F virus showed a stronger morbidity and mortality than M virus. Remarkably, a higher proportion of mice presenting infectious virus in the hearts, was found in F virus-infected animals. Altogether, the data indicate that strains of pH1N1 virus with enhanced pathogenicity circulated during the 2009 pandemic. In addition, examination of chemokine receptor 5 (CCR5) genotype, recently reported as involved in severe influenza virus disease, revealed that the F virus-infected patient was homozygous for the deleted form of CCR5 receptor (CCR5Δ32).Funding Statement: This work was supported by Instituto de Salud Carlos III (Programa especial de investigación sobre la gripe pándemica GR09/0023, GR09/0040, GR09/0039) and Ciber de Enfermedades Respiratorias. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S

La gripe aviar ¿Una nueva amenaza pandémica?

64 p.Los virus de la gripe son agentes patógenos altamente variables que ocasionan en el hombre infecciones respiratorias en forma de epidemias anuales y pandemias ocasionales. Las pandemias gripales son producidas por virus nuevos para la población y afectan a toda la humanidad en un periodo de tiempo. Durante el siglo XX se registraron tres pandemias gripales, en 1918, 1957 y 1968, la primera de las cuales fue la más importante y ocasionó entre 20 y 40 millones de muertes. Desde 1997 se han registrado infecciones en humanos producidas por virus gripales típicos e la enfermedad en pollos, del subtipo H5N1, que normalmente ocasionan brotes recurrentes de enfermedad en aves domésticas. Desde allí, los virus H5N1 se han extendido al oeste de Asia, a África y a países de Europa oriental, en forma de brotes limitados de enfermedad en aves. Como consecuencia de la circulación de estos virus aviares, desde el año 2004 se han producido más de 290 casos en humanos, con una mortalidad de alrededor de 60%. Ante el peligro de que los virus gripales H5N1 den origen a una nueva pandemia, alertado por al Organización Mundial de la Salud en varias ocasiones, el CSIC ha decidido presentar esta obra de divulgación en la que se resume la situación desde un punto de vista científico pero accesible.Peer reviewe

Severe Acute Respiratory Syndrome Coronavirus Protein 6 Is Required for Optimal Replication▿

Severe acute respiratory syndrome coronavirus (SARS-CoV) encodes several accessory proteins of unknown function. One of these proteins, protein 6 (p6), which is encoded by ORF6, enhances virus replication when introduced into a heterologous murine coronavirus (mouse hepatitis virus [MHV]) but is not essential for optimal SARS-CoV replication after infection at a relatively high multiplicity of infection (MOI). Here, we reconcile these apparently conflicting results by showing that p6 enhances SARS-CoV replication to nearly the same extent as when expressed in the context of MHV if cells are infected at a low MOI and accelerates disease in mice transgenic for the human SARS-CoV receptor

Gripe pandémica H1N1 (2009). Experiencia de la red de laboratorios de gripe del sistema de vigilancia de la gripe en España (SVGE)

Existen tres tipos de virus de la gripe: A, B y C. Estos virus evolucionan constantemente debido a que presentan dos características principales, la primera es la falta de capacidad correctora de la polimerasa viral que hace que se acumulen mutaciones puntuales en sus genes (deriva antigénica), y la segunda la naturaleza de su genoma formando por ocho segmentos lo que le permite el intercambio de genes entre distintos virus (salto antigénico). Esta plasticidad viral ha permitido que los virus de la gripe A sean capaces de adaptarse a diferentes hospedadores y adquirir capacidades pandémicas. El sistema de vigilancia de la gripe en España (SVGE) surgió como respuesta a la preocupación de que se produjera una pandemia, máxime después de los casos de gripe aviar detectados en el ser humano. Este sistema de vigilancia esta formado por dieciséis redes de médicos generales y pediatras centinela y diecinueve servicios de epidemiología, coordinados por el Centro Nacional de Epidemiología (CNE) y una red de dieciocho laboratorios, la red de laboratorios de Españoles de Gripe (ReLEG), coordinados por el Centro Nacional de Microbiología (CNM). El objetivo de este artículo es presentar la actuación de la ReLEG durante la pandemia producida por el virus de la gripe (H1N1)2009, durante la temporada 2009-2010. La función principal de la red es la vigilancia de los virus circulantes mediante su detección y posterior caracterización genética y antigénica, incluyendo la detección de las mutaciones de resistencia que afectan a los fármacos en uso, principalmente el Oseltamivir