[show abstract][hide abstract] ABSTRACT: To evaluate trends in seasonal influenza vaccination coverage in primary healthcare workers (PHCWs) in Spain between 2008 and 2011.
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.
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.
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.
Preventive Medicine 09/2013; 57(3):206-11. · 3.50 Impact Factor
[show abstract][hide abstract] ABSTRACT: 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. Methods. We conducted a multicenter case-control study in 36 Spanish hospitals. We selected patients aged ≥18 years 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 days (or > 7 days for pandemic influenza vaccine) before the onset of symptoms (cases) or the onset of symptoms in matched cases (controls). 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 years. 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 years. The adjusted effectiveness of influenza vaccination alone was 58% (95% CI 38-72). 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.
Human vaccines & immunotherapeutics. 04/2013; 9(4).
[show abstract][hide abstract] ABSTRACT: 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 out-patient, in-patient 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 out-patient with laboratory-confirmed influenza and an out-patient control. Severe cases were considered those admitted to intensive care units or who died in the hospital (n=177). We compared the influenza vaccine status of controls and out-patient cases, in-patient cases and severe cases using conditional logistic regression adjusted for potential confounding factors. Severe and non-severe in-patient influenza cases were compared using unconditional logistic regression. Vaccine effectiveness was (1-odds ratio) x100. Results. Adjusted vaccine effectiveness was 75% (odds ratio [OR]: 0.25; 95% confidence interval [CI], 0.16-0.39) in preventing influenza out-patient cases, 60% (OR:0.40; 95% CI, 0.25-0.63) in preventing influenza-associated hospitalizations, and 89% (OR:0.11; 95% CI, 0.04-0.37) in preventing severe cases. In in-patient cases, influenza vaccination was associated with a lower risk of severe influenza (OR, 0.42; 95% CI, 0.22-0.80). Conclusions. Influenza vaccination prevented influenza cases and hospitalizations and was associated with a better prognosis in in-patients with influenza. The combined effect of these two mechanisms would explain the high effectiveness of the vaccine in preventing severe cases due to influenza.
[show abstract][hide abstract] ABSTRACT: 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.
Emergency Medicine Journal 02/2013; · 1.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: 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.
Human vaccines & immunotherapeutics. 02/2013; 9(3).
[show abstract][hide abstract] ABSTRACT: 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.
BMC Public Health 02/2013; 13(1):118. · 2.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND:: The pneumococcal conjugate vaccine (PCV) might prevent hospitalizations in children because of the role of S. pneumoniae in the complications of influenza infection. We investigated the benefit of PCV vaccination in preventing influenza hospitalization in children less than 5 years of age during the 2009-2010 pandemic wave and the 2010-2011 influenza epidemic in Spain. METHODS:: A multicenter matched case-control study was undertaken in 36 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 (RT-PCR). We selected two 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:: 194 cases and 342 controls were included in the study. In the 2009-2010 pandemic wave, the adjusted benefit in preventing hospitalization was 48% (95% CI, 1 to 76) in fully vaccinated children compared with -79% (95% CI, -341 to 27) in the 2010-2011 influenza season. CONCLUSIONS:: The results obtained suggest that, in children less than 5 years of age, PCV vaccination reduced hospitalization during the 2009 -2010 pandemic wave. By contrast, there was no observed benefit of vaccination in the 2010-2011 influenza season.
The Pediatric Infectious Disease Journal 01/2013; · 3.57 Impact Factor
[show abstract][hide abstract] ABSTRACT: Influenza is a highly contagious disease that has a significant effect on the community. During the season 2010-2011, the overall rate of hospitalization for severe confirmed influenza in Spain was estimated at 5.76 cases per 100,000 inhabitants, although this number is probably underestimating the problem. Health workers can act as vectors for nosocomial transmission of influenza virus to patients, thus their immunization is an essential aspect in programs for prevention and control of infections associated with health care.In order to investigate the influenza vaccination coverage in season 2011-2012 and in the 3 previous seasons, and also to determine the knowledge and attitudes of medical and primary care professionals in Spain as regards the seasonal and pandemic influenza vaccine, a multicentre study was conducted in 7 regions (Andalusia, Castile and Leon, Catalonia, Valencia, Madrid, Navarra and Basque Country) using an anonymous online questionnaire.The objectives and methodology of the study are presented, as well as the main lessons to be learned from the use of new information technologies and communication, together with the information available for research in Public Health are discussed.
[show abstract][hide abstract] ABSTRACT: 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.
[show abstract][hide abstract] ABSTRACT: The objective of this paper was to develop a prognostic index for severe complications among hospitalized patients with influenza A (H1N1) 2009 virus infection. We conducted a prospective observational cohort study of 618 inpatients with 2009 H1N1 virus infection admitted to 36 Spanish hospitals between July 2009 and February 2010. Risk factors evaluated included host-related factors and clinical data at admission. We developed a composite index of severe in-hospital complications (SIHC), which included: mortality, mechanical ventilation, septic shock, acute respiratory distress syndrome, and requirement for resuscitation maneuvers. Six factors were independently associated with SIHC: age >45 years, male sex, number of comorbidities, pneumonia, dyspnea, and confusion. From the β parameter obtained in the multivariate model, a weight was assigned to each factor to compute the individual influenza risk score. The score shows an area under the receiver operating characteristic (ROC) curve of 0.77. The SIHC rate was 1.9 % in the low-risk group, 10.3 % in the intermediate-risk group, and 29.6 % in the high-risk group. The odds ratio for complications was 21.8 for the high-risk group compared with the low-risk group. This easy-to-score influenza A (H1N1) 2009 virus infection risk index accurately stratifies patients hospitalized for H1N1 virus infection into low-, intermediate-, and high-risk groups for SIHC.
European Journal of Clinical Microbiology 04/2012; 31(10):2693-2701. · 3.02 Impact Factor
[show abstract][hide abstract] ABSTRACT: The objective of the study was to investigate the effectiveness of non-pharmacological interventions in preventing cases of influenza requiring hospitalization.
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.
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).
Frequent handwashing should be recommended to prevent influenza cases requiring hospitalization.
Preventive Medicine 04/2012; 54(6):434-9. · 3.50 Impact Factor
[show abstract][hide abstract] ABSTRACT: The H1N1 influenza pandemic strain has been associated with a poor prognosis in hospitalized patients. The present report evaluates the factors influencing prognosis.
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.
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).
The use of neuraminidase inhibitors decreases the length of hospital stay and admission to intensive care and/or death.
Journal of Antimicrobial Chemotherapy 03/2012; 67(7):1739-45. · 5.34 Impact Factor
[show abstract][hide abstract] ABSTRACT: Please cite this paper as: Castilla et al. (20XX) Risk factors and effectiveness of preventive measures against influenza in the community. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750-2659.2012.00361.x. 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.
Influenza and Other Respiratory Viruses 03/2012; · 1.47 Impact Factor
[show abstract][hide abstract] ABSTRACT: 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.
PLoS ONE 01/2012; 7(3):e33139. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: 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.
Revista Española de Salud Pública 02/2011; 85(1):3-15. · 0.71 Impact Factor