Nuevo brote de enfermedad por virus Ébola. Otro reto de vigilancia epidemiológica / New Ebola outbreak. Further challenges for epidemiological surveillance

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Effectiveness of neuraminidase inhibitors in reducing mortality in patients admitted to hospital with influenza A H1N1pdm09 virus infection: a meta-analysis of individual participant data.

BACKGROUND: Neuraminidase inhibitors were widely used during the 2009-10 influenza A H1N1 pandemic, but evidence for their effectiveness in reducing mortality is uncertain. We did a meta-analysis of individual participant data to investigate the association between use of neuraminidase inhibitors and mortality in patients admitted to hospital with pandemic influenza A H1N1pdm09 virus infection. METHODS: We assembled data for patients (all ages) admitted to hospital worldwide with laboratory confirmed or clinically diagnosed pandemic influenza A H1N1pdm09 virus infection. We identified potential data contributors from an earlier systematic review of reported studies addressing the same research question. In our systematic review, eligible studies were done between March 1, 2009 (Mexico), or April 1, 2009 (rest of the world), until the WHO declaration of the end of the pandemic (Aug 10, 2010); however, we continued to receive data up to March 14, 2011, from ongoing studies. We did a meta-analysis of individual participant data to assess the association between neuraminidase inhibitor treatment and mortality (primary outcome), adjusting for both treatment propensity and potential confounders, using generalised linear mixed modelling. We assessed the association with time to treatment using time-dependent Cox regression shared frailty modelling. FINDINGS: We included data for 29,234 patients from 78 studies of patients admitted to hospital between Jan 2, 2009, and March 14, 2011. Compared with no treatment, neuraminidase inhibitor treatment (irrespective of timing) was associated with a reduction in mortality risk (adjusted odds ratio [OR] 0·81; 95% CI 0·70-0·93; p=0·0024). Compared with later treatment, early treatment (within 2 days of symptom onset) was associated with a reduction in mortality risk (adjusted OR 0·48; 95% CI 0·41-0·56; p<0·0001). Early treatment versus no treatment was also associated with a reduction in mortality (adjusted OR 0·50; 95% CI 0·37-0·67; p<0·0001). These associations with reduced mortality risk were less pronounced and not significant in children. There was an increase in the mortality hazard rate with each day's delay in initiation of treatment up to day 5 as compared with treatment initiated within 2 days of symptom onset (adjusted hazard ratio [HR 1·23] [95% CI 1·18-1·28]; p<0·0001 for the increasing HR with each day's delay). INTERPRETATION: We advocate early instigation of neuraminidase inhibitor treatment in adults admitted to hospital with suspected or proven influenza infection. FUNDING: F Hoffmann-La Roche.

Brote de gripe pandémica (H1N1) 2009 en una academia militar: inicio de la circulación comunitaria en España / Pandemic influenza (H1N1) 2009 outbreak in a military academy: start of community circulation in Spain

Fundamento: El 19 de mayo de 2009 se declararon 21 casos de soldados con síntomas de infección respiratoria aguda en la Academia Militar de Ingenieros (ACING) en Hoyo de Manzanares, España. En el contexto de una alerta mundial por gripe A(H1N1) 2009, se decide investigar la posible aparición de un brote por este virus. El objetivo es describir un posible brote de gripe (H1N1) 2009 en un Centro de Formación Militar y describir las medidas adoptadas, en la fase de contención, para evitar su transmisión. Métodos: Se administró un cuestionario específico y se recogieron muestras biológicas a todos los casos en investigación. Se recomendaron aislamiento y cuarentena, respectivamente de los casos y contactos. Resultados: Se confirmaron 81 casos de infección por virus de la gripe A (H1N1)2009. De las 52 muestras procesadas 31 fueron positivas para virus influenza A/California/7/2009. La edad media de los casos fue 22,0 años (rango, 18-31). El 84% eran varones. Los síntomas más comunes fueron tos y fiebre. Todos los casos permanecieron aislados y fueron tratados con oseltamivir, con buena evolución. La tasa de ataque global fue 12,42%. Ningún caso tenía antecedentes de viaje a zonas de riesgo o vinculo epidemiológico con un caso diagnosticado previamente fuera de la ACING. Se identificaron 31 casos relacionados con este brote fuera de la ACING, 24 casos eran contactos familiares y amigos. Conclusiones: Este brote alertó del inicio de la circulación comunitaria del virus pandémico en España. La detección precoz del mismo favoreció la puesta en marcha de medidas para la contención de su trasmisión(AU)

Background: On May 19, 2009, 21 cases of influenza-like illness were reported among soldiers from an Engineering Military Academy (ACING) in Hoyo de Manzanares, Spain. In the context of an influenza A (H1N1)2009 global alert, it was decided to investigate a possible pandemic influenza outbreak. To describe a possible outbreak of influenza A (H1N1)2009 in a Military Training Centre and to describe the measures adopted for transmission control of this new infection. Methods: A specific questionnaire was administered and biological samples were collected from all cases under investigation. Isolation and quarantine were recommended for cases and contacts, respectively. Results: Eighty-one cases were confirmed. Among 52 samples tested, 31 were positive for influenza virus A/California/7/2009. The average age of the cases was 22.0 years (range 18-31 years) and 84% were men. Most common reported symptoms were cough and fever. All cases were isolated and treated with oseltamivir, with full recovery. The total attack rate was 12.42%. None of the cases had history of travel to risk areas or contact with previously diagnosed cases outside the academy. Thirty-one confirmed cases related to this outbreak were identified outside the academy, 24 cases were family contacts and friends. Conclusions: This outbreak was the first evidence of community transmission of pandemic influenza H1N1 in Spain. The rapid detection of this outbreak enhanced an early implementation of measures aiming at the containment of its transmission(AU)

[Pandemic influenza (H1N1) 2009 Outbreak in a Military Academy: start of community circulation in Spain]. / Brote de gripe pandémica (H1N1) 2009 en una academia militar: inicio de la circulación comunitaria en España.

BACKGROUND: On May 19, 2009, 21 cases of influenza-like illness were reported among soldiers from an Engineering Military Academy (ACING) in Hoyo de Manzanares, Spain. In the context of an influenza A (H1N1)2009 global alert, it was decided to investigate a possible pandemic influenza outbreak. To describe a possible outbreak of influenza A (H1N1)2009 in a Military Training Centre and to describe the measures adopted for transmission control of this new infection. METHODS: A specific questionnaire was administered and biological samples were collected from all cases under investigation. Isolation and quarantine were recommended for cases and contacts, respectively. RESULTS: Eighty-one cases were confirmed. Among 52 samples tested, 31 were positive for influenza virus A/California/7/2009. The average age of the cases was 22.0 years (range 18-31 years) and 84% were men. Most common reported symptoms were cough and fever. All cases were isolated and treated with oseltamivir, with full recovery. The total attack rate was 12.42%. None of the cases had history of travel to risk areas or contact with previously diagnosed cases outside the academy. Thirty-one confirmed cases related to this outbreak were identified outside the academy, 24 cases were family contacts and friends. CONCLUSIONS: This outbreak was the first evidence of community transmission of pandemic influenza H1N1 in Spain. The rapid detection of this outbreak enhanced an early implementation of measures aiming at the containment of its transmission.

Influenza vaccination among persons with chronic respiratory diseases: coverage, related factors and time-trend, 1993-2001.

BACKGROUND: Influenza vaccination has shown itself to be effective in reducing morbidity and mortality in patients with underlying chronic respiratory diseases. This study sought to: (1) estimate influenza vaccination coverage among asthma and chronic bronchitis sufferers; (2) ascertain which variables were associated with vaccination; and (3) analyse the time-trend in coverage between 1993 and 2001. METHODS: This was a descriptive study covering the 2611 subjects included in the 1993, 1995, 1997 and 2001 Spanish National Health Surveys who reported suffering from asthma or chronic bronchitis. Vaccination coverage was calculated for each year and the influence of socio-demographic and health-related variables analysed. Using logistic regression, we assessed which of the variables had an independent effect on vaccination, and analysed the time-trend. RESULTS: The proportions of vaccinated subjects in 1993, 1995-1997 and 2001 were 44.7%, 45.6% and 44.4%, respectively. Variables that increased the likelihood of having been vaccinated were: higher age, presence of another concomitant chronic disease, poor perception of health, non-smoker status, and being married. There was no significant variation in coverage over the study period. CONCLUSION: Influenza vaccination coverage among Spanish asthma and/or chronic bronchitis sufferers is below desirable levels and showed no improvement over the period 1993-2001. Implementation of strategies to improve coverage is necessary.

Evolution of anti-influenza vaccination coverage in Spain from 1993 to 2001.

UNLABELLED: The objective of this study is to describe the evolution of anti-influenza vaccination coverage in Spain from 1993 to 2001. We analysed 55,040 questionnaires taken from the Spanish National Health Surveys from the years 1993, 1995, 1997 and 2001. The reply to the question "Did you vaccinate yourself against influenza during the last campaign?" is the dependent variable. Independent variables were the year of the survey, age, sex and the coexistence of chronic conditions. After adjusting using logistic regression, we found a significant improvement during the study period among those subjects at risk of suffering complications from influenza (OR 1.21). Nevertheless, this increase was essentially at the cost of subjects aged 65 and over. Subjects with high-risk conditions under 65 did not undergo significant changes. CONCLUSIONS: A significant but insufficient improvement has been achieved and this must lead us to consider the possible need to modify anti-influenza vaccination recommendations.

[Evolution of the degrees of influenza vaccine (flu shot) coverage in Spain throughout the 1993-2001 period. Analysis by Autonomous Communities]. / Evolución de las coberturas vacunales antigripales entre 1993-2001 en España. Análisis por Comunidades Autónomas.

BACKGROUND: Influenza (flu) is a disease involving a high morbidity which takes a high toll on healthcare costs for which there is an effective vaccine available. This study is aimed at evaluating the evolution of the different degrees of influenza vaccine (flu shot) coverage in Spain by Autonomous Communities during the 1993-2001 period. METHODS: A total of 42,123 cases from the National Health Survey (NHS) for the years 1993 (n=21,051) and 2001 (n=21,072) were analysed, all of which corresponded to non-institutionalised Spanish adults over 15 years of age. Both surveys are representative at the Autonomous Community level. RESULTS: For the total sample, a vaccine coverage of 17.94% (CI 95% 17.42-18.46) in 1993 and of 19.30% (18.77-19.83) en 2001 was estimated. In the logic regression model, adjusted by age, sex and related chronic disease, significant improvements were found in the degrees of coverage of individuals over 64 years of age (OR = 1.28 CI 95% 1.10-1.50) for Spain as a whole and for five of the seventeen Autonomous Communities between 1993 and 2001. However, no significant changes were found in the degrees of coverage for the group under age 65 with related chronic disease entailing an indication for being administered the vaccine. CONCLUSIONS: A slight yet insufficient improvement in the degrees of coverage among the high-risk groups studied were found to exist both nation-wide in Spain as a whole as well as in the majority of the Autonomous Communities between 1993 and 2001. Degrees of coverage varied greatly among Autonomous Communities. The individual under age 65 with related chronic diseases heightening the risks of suffering from flu-related complications have not improved their degrees of coverage regarding this vaccine during the period studied. The difficulty involved in improving the degrees of coverage among this type of patients might lead us to consider the alternative and potential benefit of lowering the age limit of the current influenza vaccine (flu shot) indication-related recommendations in Spain.