Smoking may increase the risk of hospitalization due to influenza.

BACKGROUND: Smoking may facilitate influenza virus infections and their severity. The objective was to investigate the risk of hospitalization due to influenza in Spanish smokers and ex-smokers. METHODS: We carried out a multicentre, case-control study in 2011. Cases [patients ≥ 18 years hospitalized > 24 h with real time polymerase chain reaction (RT-PCR)-confirmed influenza] were selected from 29 Spanish hospitals. For each case, we selected an outpatient aged ≥ 18 years with RT-PCR-confirmed influenza matched by age (±5 years), date of hospitalization of the case (±10 days) and province of residence. We collected epidemiological variables, comorbidities and the smoking history. The risk of hospitalization due to smoking was determined by the adjusted odds ratio (aOR) using logistic regression. RESULTS: We studied 471 hospitalized cases and 476 outpatient cases. Hospitalized cases had a higher frequency of influenza risk factors compared with outpatient cases. Hospitalized cases had a higher frequency of smoking (30.9% vs. 17.1%) and being ex-smokers (29.3% vs. 25.3%). Current smoking (aOR = 2.18, 95% CI: 1.23-3.87) and being an ex-smoker (aOR = 1.73, 95% CI: 1.07-2.82) were associated with the risk of hospitalization. CONCLUSIONS: Smoking may increase the risk of hospitalization in smokers and ex-smokers when infected by the influenza virus. Smoking prevention could reduce hospitalizations. Influenza vaccination is recommended for smokers.

Pandemic influenza A (H1N1) in non-vaccinated, pregnant women in Spain (2009-2010).

The aim of this study was to investigate the main characteristics of non-vaccinated pregnant women who were hospitalised for influenza A (H1N1) pdm09 pandemic versus pregnant women hospitalised for non-influenza-related reasons in Spain, and to characterise the clinical presentation of the disease in this population to facilitate early diagnosis and future action programmes. Understanding influenza infection during pregnancy is important as pregnant women are a high-risk population for increased morbidity from influenza infection. We investigated the socio-demographic and clinical features of 51 non-vaccinated, pregnant women infected with the pandemic influenza A (H1N1) virus in Spain (cases) and compared them to 114 controls (non-vaccinated and non-infected pregnant women) aged 15-44 years. Substantial and significant odd ratios (ORs) for pandemic influenza A (H1N1) were found for the pregnant women who were obese compared with controls (body mass index > 30) (OR 3.03; 95% confidence intervals 1.13-8.11). The more prevalent symptoms observed in pandemic influenza-infected pregnant women were high temperature, cough (82.4%), malaise (80.5%), myalgia (56.1%), and headaches (54.9%). Our results suggest that the initial symptoms and risk factors for infection of pregnant women with the influenza A (H1N1) pdm09 virus are similar to the symptoms and risk factors for seasonal influenza, which make early diagnosis difficult, and reinforces the need to identify and protect high-risk groups.

Predictive factors of severe multilobar pneumonia and shock in patients with influenza.

PURPOSE: To identify risk factors present at admission in adult patients hospitalised due to influenza virus infection during the 2009/10 and 2010/11 seasons--including whether infection was from pandemic or seasonal influenza A infections--that were associated with the likelihood of developing severe pneumonia with multilobar involvement and shock. METHODS: Prospective cohort study. Patients hospitalised due to influenza virus infection were recruited. We collected information on sociodemographic characteristics, pre-existing medical conditions, vaccinations, toxic habits, previous medications, exposure to social environments, and EuroQoL-5D (EQ-5D). Severe pneumonia with multilobar involvement and/or shock (SPAS) was the primary outcome of interest. We constructed two multivariate logistic regression models to explain the likelihood of developing SPAS and to create a clinical prediction rule for developing SPAS that includes clinically relevant variables. RESULTS: Laboratory-confirmed A(H1N1)pdm09, EQ-5D utility score 7 days before admission, more than one comorbidity, altered mental status, dyspnoea on arrival, days from onset of symptoms, and influenza season were associated with SPAS. In addition, not being vaccinated against seasonal influenza in the previous year, anaemia, altered mental status, fever and dyspnoea on arrival at hospital, difficulties in performing activities of daily living in the previous 7 days, and days from onset of symptoms to arrival at hospital were related to the likelihood of SPAS (area under the curve value of 0.75; Hosmer-Lemeshow p value of 0.84). CONCLUSIONS: These variables should be taken into account by physicians evaluating a patient affected by influenza as additional information to that provided by the usual risk scores.

Influenza vaccine effectiveness in preventing outpatient, inpatient, and severe cases of laboratory-confirmed influenza.

BACKGROUND: In most seasons, the influenza vaccine is effective in preventing influenza, but it is not clear whether it is equally effective in preventing mild and severe cases. We designed a case-control study to compare the effectiveness of the influenza vaccine in preventing outpatient, inpatient, and severe or fatal cases of laboratory-confirmed influenza. METHODS: Hospitalized patients (n = 691) with laboratory-confirmed influenza in the 2010-2011 season recruited in 29 Spanish hospitals were individually matched by age, admission/visit date, and province with an outpatient with laboratory-confirmed influenza and an outpatient control. Severe cases were considered those patients admitted to intensive care units or who died in the hospital (n = 177). We compared the influenza vaccine status of controls and outpatient cases, inpatient cases, and severe cases using conditional logistic regression adjusted for potential confounding factors. Severe and nonsevere inpatient influenza cases were compared using unconditional logistic regression. Vaccine effectiveness was (1 - odds ratio) × 100. RESULTS: Vaccine effectiveness was 75% (adjusted odds ratio [AOR], 0.25; 95% confidence interval [CI], .16-.39) in preventing influenza outpatient cases, 60% (AOR, 0.40; 95% CI, .25-.63) in preventing influenza-associated hospitalizations, and 89% (AOR, 0.11; 95% CI, .04-.37) in preventing severe cases. In inpatients, influenza vaccination was associated with a lower risk of severe influenza (AOR, 0.42; 95% CI, .22-.80). CONCLUSIONS: Influenza vaccination prevented influenza cases and hospitalizations and was associated with a better prognosis in inpatients with influenza. The combined effect of these 2 mechanisms would explain the high effectiveness of the vaccine in preventing severe cases due to influenza.

Trends in influenza vaccine coverage among primary healthcare workers in Spain, 2008-2011.

OBJECTIVE: To evaluate trends in seasonal influenza vaccination coverage in primary healthcare workers (PHCWs) in Spain between 2008 and 2011. METHODS: We made an anonymous web survey of PHCWs in 2012. Information on attitudes towards and knowledge of influenza vaccine, and immunization in previous seasons was collected. Self-reported vaccination coverage and factors related to vaccination continuity were analysed. RESULTS: Of 5433 workers contacted, 2625 (48.3%) responded to the survey: 47.0% were general practitioners, 10.3% paediatricians and 42.7% nurses. Their reported vaccination rates from seasons 2008-2009 to 2011-2012 decreased over time: 58.4%, 57.4%, 53.2% and 49.3% (linear trend, p < 0.001). Among workers vaccinated in any previous season, 70.2% were vaccinated again in 2011-2012, compared with 5.2% among those not previously vaccinated (p < 0.001). Continuity of vaccination increased with age and with the worker or cohabitant having a major chronic condition. Vaccination was higher in workers who recognized vaccination as effective and those worried about being infected or infecting patients. CONCLUSION: Influenza vaccination coverage in PHCWs has declined, especially after the pandemic. Intensive interventions are needed to change this trend. Knowledge of vaccination should be reinforced by stressing the effectiveness of the vaccine and the risks of influenza for workers and patients.

Social factors related to the clinical severity of influenza cases in Spain during the A (H1N1) 2009 virus pandemic.

BACKGROUND: During the 2009 influenza pandemic, a change in the type of patients most often affected by influenza was observed. The objective of this study was to assess the role of individual and social determinants in hospitalizations due to influenza A (H1N1) 2009 infection. METHODS: We studied hospitalized patients (cases) and outpatients (controls) with confirmed influenza A (H1N1) 2009 infection. A standardized questionnaire was used to collect data. Variables that might be related to the hospitalization of influenza cases were compared by estimation of the odds ratio (OR) and 95% confidence intervals (CI) and the variables entered into binomial logistic regression models. RESULTS: Hospitalization due to pandemic A (H1N1) 2009 influenza virus infections was associated with non-Caucasian ethnicity (OR: 2.18, 95% CI 1.17 - 4.08), overcrowding (OR: 2.84, 95% CI 1.20 - 6.72), comorbidity and the lack of previous preventive information (OR: 2.69, 95% CI: 1.50 - 4.83). Secondary or higher education was associated with a lower risk of hospitalization (OR 0.56, 95% CI: 0.36 - 0.87) CONCLUSIONS: In addition to individual factors such as comorbidity, other factors such as educational level, ethnicity or overcrowding were associated with hospitalization due to A (H1N1) 2009 influenza virus infections.

Prognosis of hospitalized patients with 2009 H1N1 influenza in Spain: influence of neuraminidase inhibitors.

BACKGROUND: The H1N1 influenza pandemic strain has been associated with a poor prognosis in hospitalized patients. The present report evaluates the factors influencing prognosis. METHODS: A total of 813 patients hospitalized with H1N1 influenza in 36 hospitals (nationwide) in Spain were analysed. Detailed histories of variables preceding hospital admission were obtained by interview, validating data on medications and vaccine with their attending physicians. Data on treatment and complications during hospital stay were recorded. As definition of poor outcome, the endpoints of death and admission to intensive care were combined; and as a further outcome, length of stay was used. RESULTS: The mean age was 38.5 years (SD 22.8 years). There were 10 deaths and 79 admissions to intensive care (combined, 88). The use of neuraminidase inhibitors was reported by 495 patients (60.9%). The variables significantly associated with a poor outcome were diabetes (OR = 2.21, 95% CI = 1.21-4.02), corticosteroid therapy (OR = 3.37, 95% CI = 1.39-8.20) and use of histamine-2 receptor antagonists (OR = 2.68, 95% CI = 1.14-6.36), while the use of neuraminidase inhibitors (OR = 0.57, 95% CI = 0.34-0.94) was protective. Neuraminidase inhibitors within the first 2 days after the influenza onset reduced hospital stay by a mean of 1.9 days (95% CI = 4.7-6.6). CONCLUSIONS: The use of neuraminidase inhibitors decreases the length of hospital stay and admission to intensive care and/or death.

Effectiveness of hand hygiene and provision of information in preventing influenza cases requiring hospitalization.

BACKGROUND: The objective of the study was to investigate the effectiveness of non-pharmacological interventions in preventing cases of influenza requiring hospitalization. METHODS: We performed a multicenter case-control study in 36 hospitals, in 2010 in Spain. Hospitalized influenza cases confirmed by reverse-transcription polymerase chain reaction and three matched controls (two hospital and one community control) per case were selected. The use of non-pharmacological measures seven days before the onset of symptoms (frequency of hand washing, use of alcohol-based hand sanitizers and handwashing after touching contaminated surfaces) was collected. RESULTS: We studied 813 cases hospitalized for influenza and 2274 controls. The frequency of hand washing 5-10 times (adjusted odds ratio [aOR]=0.65) and >10 times (aOR=0.59) and handwashing after contact with contaminated surfaces (aOR=0.65) were protective factors and were dose-responsive (p<0.001). Alcohol-based hand sanitizers were associated with marginal benefits (aOR=0.82). CONCLUSIONS: Frequent handwashing should be recommended to prevent influenza cases requiring hospitalization.

Managing an online survey about influenza vaccination in primary healthcare workers.

Online surveys are increasingly used due to their speed and efficiency. The aim of this study was to analyze factors that may have contributed to the quality and speed of response of an online survey on influenza vaccination in primary healthcare workers. A multicenter study including family physicians, nurses and pediatricians from primary healthcare teams from seven Spanish Autonomous Communities was designed. The centers were selected by simple random sampling. The survey remained active and accessible for 56 days and four reminders were sent. The odds ratios (OR) and their 95% confidence intervals (CI) were calculated to assess the association of sociodemographic variables and responding to the survey before the second reminder. Complete, validated information was obtained from 1965 primary healthcare workers. The total response rate was 36.2%. More nurses (46.3%) responded before the second reminder and more family physicians (52.8%) after the second reminder. The adjusted OR shows that family physicians responded later (AOR 1.46, 95% CI 1.2-1.8) than nurses. The responses obtained in the first 24 h after the initial sending and the reminders accounted for 41.7% of the completed surveys, indicating the importance of reminders.

Pandemic influenza A (H1N1) infection in pregnant and nonpregnant women in Spain (2009-2010).

The present study aimed to compare the main features of infection with pandemic influenza A virus in pregnant and nonpregnant women admitted to hospitals in Spain during the first waves of the 2009-2010 influenza pandemic. This was a prospective (November 2009 to June 2010), multicenter observational study. All cases were women of reproductive age who had not been vaccinated against seasonal or pandemic influenza A. Influenza infection was confirmed by reverse transcription-polymerase chain reaction (RT-PCR). The sociodemographic and clinical data of all cases were reviewed. A total of 219 inpatients, including 49 pregnant women and 170 nonpregnant women, were enrolled in the study upon admission to participating hospitals. The most substantially different symptoms between the groups were respiratory distress and unilobar consolidation, both of which were more frequent among nonpregnant women. Antibiotics and systemic corticosteroids were more frequently used in nonpregnant women; however, there were no differences in the rates of treatment with antivirals. Our findings indicated that the compared with nonpregnant women, pregnant women in this study did not have significantly different symptoms and were not at increased risk of complications from pandemic influenza virus infection.

Influenza sentinel surveillance network: a public health-primary care collaborative action to assess influenza A(H1N1)pmd09 in Catalonia, Spain.

The aim of this study was to evaluate the outcome of a collaborative action between Public Health services and Primary Care in the context of a case-control study on effectiveness of pharmaceutical and non-pharmaceutical measures to prevent hospitalization in a pandemic situation. To carry out this research the collaborative action of the primary care physicians members of the Influenza surveillance network was needed, they had to recall clinical information from influenza A(H1N1)pmd09 confirmed outpatient cases and negative outpatient controls matching their corresponding hospitalized confirmed case.   A survey questionnaire to assess involvement of Influenza Sentinel Surveillance Primary care physicians' Network of Catalonia (PIDIRAC) regarding the outpatient case and control outreach during the pandemic influenza season was performed. A total of 71,1% of completed surveys were received. Perception of pandemic activity was considered to be similar to seasonal influenza activity in 43.8% or higher but not unbearable in 37.5% of the replies. There was no nuisance reported from patients regarding neither the questions nor the surveyor. Collaborative research between Public Health services and Primary Care physicians enhances Public Health actions and research.

Risk factors and effectiveness of preventive measures against influenza in the community.

BACKGROUND: The role of different risk exposures and preventive measures against influenza has not been well established. OBJECTIVE: The aim of this study was to evaluate risk factors and measures to prevent influenza infection in the community. METHODS: We conducted a multicenter case-control study. Cases were 481 outpatients aged 18 years or older with laboratory-confirmed influenza A(H1N1)09 in the 2009-2010 season in Spain. A control was selected for each case from outpatients from the same area matched by age and date of consultation. Information on risk situations, preventive measures and other variables was obtained by interview and review of the medical record. RESULTS: In the multivariate conditional logistic regression analysis, the risk of a diagnosis of influenza increased with the number of cohabitants (compared with <3 cohabitants, three cohabitants had an OR= 1·80, 95% CI 1·12-2·89, and ≥5 cohabitants had an OR = 2·66, 95% CI 1·31-5·41) and for health care workers (OR = 2·94, 95% CI 1·53-5·66). The use of metropolitan public transport was associated with a lower frequency of a diagnosis of influenza (OR = 0·45, 95% CI 0·30-0·68) but not the use of taxis or long-distance transport. The influenza A(H1N1)09 vaccine had a protective effect (OR =0·13, 95% CI 0·04-0·48), unlike hand washing after touching contaminated surfaces or the use of alcohol-based hand sanitizers. CONCLUSION: The home environment appears to play an important role in the spread of influenza in adults, but not the use of public transport. Health care workers have a higher risk of contracting influenza. Vaccination was the most effective preventive measure.

Effectiveness of vaccination with 23-valent pneumococcal polysaccharide vaccine in preventing hospitalization with laboratory confirmed influenza during the 2009-2010 and 2010-2011 seasons.

BACKGROUND: Since influenza predisposes to bacterial pneumonia caused by Streptococcus pneumoniae, studies have suggested that pneumococcal vaccination might reduce its occurrence during pandemics. We assessed the effectiveness of pneumococcal polysaccharide vaccination alone and in combination with influenza vaccination in preventing influenza hospitalization during the 2009-2010 pandemic wave and 2010-2011 influenza epidemic. RESULTS: 1187 cases and 2328 controls were included. The adjusted estimate of effectiveness of pneumococcal vaccination in preventing influenza hospitalization was 41% (95% CI 8-62) in all patients and 43% (95% CI 2-78) in patients aged ≥ 65 y. The adjusted effectiveness of dual PPV23 and influenza vaccination was 81% (95% CI 65-90) in all patients and 76% (95% CI 46-90) in patients aged ≥ 65 y. The adjusted effectiveness of influenza vaccination alone was 58% (95% CI 38-72). METHODS: We conducted a multicenter case-control study in 36 Spanish hospitals. We selected patients aged ≥ 18 y hospitalized with confirmed influenza and two hospitalized controls per case, matched according to age, date of hospitalization and province of residence. Multivariate analysis was performed using conditional logistic regression. Subjects were considered vaccinated if they had received the pneumococcal or seasonal influenza vaccine>14 d (or>7 d for pandemic influenza vaccine) before the onset of symptoms (cases) or the onset of symptoms in matched cases (controls). CONCLUSIONS: In elderly people and adults with chronic illness, pneumococcal vaccination may reduce hospitalizations during the influenza season. In people vaccinated with both the influenza and pneumococcal vaccines, the benefit in hospitalizations avoided was greater than in those vaccinated only against influenza.

Different prognosis in hospitalized patients with influenza one season after the pandemic H1N1 influenza of 2009-2010 in Spain.

BACKGROUND: The present report compares prognosis in hospitalized cases with the H1N1 pandemic virus in two seasons. METHODS: Two series of hospitalized patients with laboratory-confirmed H1N1 pandemic influenza have been compared: 813 in the season 2009-2010 and 707 in the season 2010-2011. A detailed history of variables preceding hospital admission and during hospitalization was obtained by interview and clinical charts. A combined endpoint of death admission to intensive care was used as outcome due to the low number of deaths. Logistic regression was applied in the analysis for adverse outcome. RESULTS: Patients of the second season had different characteristics than in the first one (older, more underlying conditions, more malfunctioning organs and more symptoms). Patients with H1N1 pandemic virus when hospitalized were more frequently directly admitted to ICU during the 2010-2011 season than in the previous season (RR=2·10; 95% confidence intervals CI, 1·55-2·85), as a consequence of a higher presence of sepsis and respiratory distress. These patients also showed during hospitalization a higher risk of ICU admission or death (RR=3·22, 95% CI, 2·15-4·83). After adjusting for the differences in risk factors of adverse outcome, patients in the second season showed a higher risk of ICU admission and/or in-hospital death odds ratio (OR=3·77, 95% CI, 2·30-6·18). CONCLUSION: Hospitalized patients with H1N1 pandemic influenza during the second season were more severely affected at hospital admission and showed a worse prognosis than in previous season, independently of the differences found at hospital admission.

Benefit of conjugate pneumococcal vaccination in preventing influenza hospitalization in children: a case-control study.

BACKGROUND: The pneumococcal conjugate vaccine (PCV) might prevent hospitalizations in children because of the role of Streptococcus pneumoniae in the complications of influenza infection. We investigated the benefit of PCV vaccination in preventing influenza hospitalization in children <5 years of age during the 2009 to 2010 pandemic wave and the 2010 to 2011 influenza epidemic in Spain. METHODS: A multicenter matched case-control study was undertaken in 27 hospitals from 7 Spanish regions between July 2009 and April 2011. A case was defined as a hospitalized patient between 6 months and 5 years of age with influenza virus infection confirmed by real-time reverse-transcription polymerase chain reaction. We selected 2 matched controls for each case from patients with unplanned hospital admission for reasons other than acute respiratory infection or influenza-like illness. Cases and controls were matched according to age, date of hospitalization and province of residence. Crude and adjusted odds ratios were calculated for associations between influenza hospitalization and PCV vaccination. RESULTS: One hundred ninety-four cases and 342 controls were included in the study. In the 2009 to 2010 pandemic wave, the adjusted benefit in preventing hospitalization was 48% (95% confidence interval: 1 to 76) in fully vaccinated children compared with -79% (95% confidence interval: -341 to 27) in the 2010 to 2011 influenza season. CONCLUSIONS: The results obtained suggest that, in children <5 years of age, PCV vaccination reduced hospitalization during the 2009 to 2010 pandemic wave. By contrast, there was no observed benefit of vaccination in the 2010 to 2011 influenza season.

Effectiveness of pandemic and seasonal influenza vaccines in preventing pandemic influenza-associated hospitalization.

Vaccines are leading pharmacological measures for limiting the impact of pandemic influenza in the community. The objective of this study was to investigate the effectiveness of influenza (pandemic and seasonal) vaccines in preventing pandemic influenza-associated hospitalization. We conducted a multicenter matched case-control study in 36 Spanish hospitals. Patients hospitalized with confirmed pandemic influenza between November 2009 and February 2010 and two hospitalized controls per case, matched according to age, date of hospitalization and province of residence, were selected. Multivariate analysis was performed using conditional logistic regression. Subjects were considered vaccinated if they had received the vaccine >14 days (seasonal influenza vaccine) or >7 days (pandemic influenza vaccine) before the onset of symptoms (cases) or the onset of symptoms of the matched case (controls). For the pandemic influenza vaccine, vaccination effectiveness (VE) was estimated taking into account only patients recruited from November 23, 2009, seven days after the beginning of the pandemic influenza vaccination campaign. 638 cases and 1250 controls were included. The adjusted VE of the pandemic vaccine in the ≥18 years age group was 74.2% (95% CI, 29-90) and that of the influenza seasonal vaccine 15.0% (-34 to 43). The recommendation of influenza vaccination should be reinforced as a regular measure to reduce influenza-associated hospitalization during pandemics and seasonal epidemics.

Sociodemographic factors and clinical conditions associated to hospitalization in influenza A (H1N1) 2009 virus infected patients in Spain, 2009-2010.

The emergence and pandemic spread of a new strain of influenza A (H1N1) virus in 2009 resulted in a serious alarm in clinical and public health services all over the world. One distinguishing feature of this new influenza pandemic was the different profile of hospitalized patients compared to those from traditional seasonal influenza infections. Our goal was to analyze sociodemographic and clinical factors associated to hospitalization following infection by influenza A(H1N1) virus. We report the results of a Spanish nationwide study with laboratory confirmed infection by the new pandemic virus in a case-control design based on hospitalized patients. The main risk factors for hospitalization of influenza A (H1N1) 2009 were determined to be obesity (BMI≥40, with an odds-ratio [OR] 14.27), hematological neoplasia (OR 10.71), chronic heart disease, COPD (OR 5.16) and neurological disease, among the clinical conditions, whereas low education level and some ethnic backgrounds (Gypsies and Amerinds) were the sociodemographic variables found associated to hospitalization. The presence of any clinical condition of moderate risk almost triples the risk of hospitalization (OR 2.88) and high risk conditions raise this value markedly (OR 6.43). The risk of hospitalization increased proportionally when for two (OR 2.08) or for three or more (OR 4.86) risk factors were simultaneously present in the same patient. These findings should be considered when a new influenza virus appears in the human population.

[Risk factors of influenza (H1N1) 2009 hospitalization and effectiveness of pharmaceutical and nonpharmaceutical interventions in its prevention: a case-control study]. / Factores de riesgo de hospitalización por gripe (H1N1) 2009 y efectividad de intervenciones farmacológicas y no farmacológicas en su prevención: Estudio de casos y controles.

Potentially useful pharmaceutical measures to limit the impact of pandemic influenza in the community include antiviral drugs (neuraminidase inhibitors) and the influenza and pneumococcal vaccines, as influenza predisposes to bacterial pneumonia caused by Streptococcus pneumoniae. Non-pharmaceutical measures include hand washing and respiratory hygiene. Due to the lack of knowledge of the effectiveness of these measures in a pandemic situation, in September 2009, CIBER de Epidemiología y Salud Pública presented a multicenter case-control study, with controls matched for age, hospital and date of hospitalization, to investigate these aspects in 37 hospitals in 7 Spanish autonomous communities, in response to the call for research projects by the Ministry of Science and Innovation Research Program on Influenza A (H1N1) in Spain. For each confirmed hospitalized case of pandemic influenza, 1 confirmed outpatient case and 3 controls (2 hospitalized and 1 outpatient) were selected. Demographic variables, underlying medical conditions, use of antiviral agents, vaccines received and hygiene habits were collected for all cases and controls. In hospitalized cases, information on antiviral therapy and disease progression was collected. A total of 3750 patients were recruited by October 2010. Data cleansing and the recovery of variables is now underway. The involvement of the Public Health Directorate has been instrumental in adapting the project to the evolution of the pandemic.

Factores de riesgo de hospitalización por gripe (H1N1) 2009 y efectividad de intervenciones farmacológicas y no farmacológicas en su prevención. Estudio de casos y controles / Risk factors of influenza (H1N1) 2009 hospitalization and effectiveness of pharmaceutical and nonpharmaceutical interventions in its prevention. A case-control study

Entre las medidas farmacológicas de posible utilidad para limitar el impacto de las pandemias gripales en la comunidad están los fármacos antivirales (inhibidores de la neuraminidasa) y las vacunas antigripales y antineumocócicas, ya que la gripe predispone a la neumonía bacteriana por Streptococcus pneumoniae. Entre las medidas no farmacológicas destacan la higiene de manos y la higiene respiratoria. La falta de conocimiento de la efectividad de dichas medidas en situación de pandemia justifica que en septiembre de 2009, ante la solicitud de proyectos de investigación por parte del Ministerio de Ciencia e Innovación en su Programa de Investigación sobre la gripe (H1N1) 2009 en España, el CIBER de Epidemiología y Salud Pública presentara un proyecto multicéntrico de casos y controles emparejados por edad, hospital y fecha de hospitalización para investigar sobre estos aspectos en 37 hospitales de 7 comunidades autónomas. Por cada caso hospitalizado confirmado de gripe pandémica se seleccionaba 1 caso confirmado ambulatorio y 3 controles (2 hospitalarios y 1 ambulatorio). En los casos y en los controles se recogían variables demográficas, condiciones médicas subyacentes, utilización de antivirales, vacunas recibidas y hábitos de higiene. En los casos hospitalizados se recogieron, además, información relativa al tratamiento antiviral y evolución de la enfermedad. Hasta octubre 2010 se habían reclutado un total de 3.750 pacientes y se está realizando la depuración de los datos y la recuperación de variables. La implicación de las Direcciones Generales de Salud Pública ha sido fundamental para la adecuación del proyecto a la evolución de la pandemia(AU)

Potentially useful pharmaceutical measures to limit the impact of pandemic influenza in the community include antiviral drugs (neuraminidase inhibitors) and the influenza and pneumococcal vaccines, as influenza predisposes to bacterial pneumonia caused by Streptococcus pneumoniae. Non-pharmaceutical measures include hand washing and respiratory hygiene. Due to the lack of knowledge of the effectiveness of these measures in a pandemic situation, in September 2009, CIBER de Epidemiología y Salud Pública presented a multicenter case-control study, with controls matched for age, hospital and date of hospitalization, to investigate these aspects in 37 hospitals in 7 Spanish autonomous communities, in response to the call for research projects by the Ministry of Science and Innovation Research Program on InfluenzaA(H1N1) in Spain. For each confirmed hospitalized case of pandemic influenza, 1 confirmed outpatient case and 3 controls (2 hospitalized and 1 outpatient) were selected. Demographic variables, underlying medical conditions, use of antiviral agents, vaccines received and hygiene habits were collected for all cases and controls. In hospitalized cases, information on antiviral therapy and disease progression was collected. A total of 3750 patients were recruited by October 2010. Data cleansing and the recovery of variables is now underway. The involvement of the Public Health Directorate has been instrumental in adapting the project to the evolution of the pandemic(AU)