Effectiveness of the trivalent influenza vaccine in Navarre, Spain, 2010-2011: a population-based test-negative case-control study.

BACKGROUND: Some studies have evaluated vaccine effectiveness in preventing outpatient influenza while others have analysed its effectiveness in preventing hospitalizations. This study evaluates the effectiveness of the trivalent influenza vaccine in preventing outpatient illness and hospitalizations from laboratory-confirmed influenza in the 2010-2011 season. METHODS: We conducted a nested case-control study in the population covered by the general practitioner sentinel network for influenza surveillance in Navarre, Spain. Patients with influenza-like illness in hospitals and primary health care were swabbed for influenza testing. Influenza vaccination status and other covariates were obtained from health care databases. Using logistic regression, the vaccination status of laboratory-confirmed influenza cases was compared with that of test-negative controls, adjusting for age, sex, comorbidity, outpatient visits in the previous 12 months, health care setting, time between symptom onset and swabbing, period and A(H1N1)pdm09 vaccination. Effectiveness was calculated as (1-odds ratio)x100. RESULTS: The 303 confirmed influenza cases (88% for A(H1N1)pdm09 influenza) were compared with the 286 influenza test-negative controls. The percentage of persons vaccinated against influenza was 4.3% and 15.7%, respectively (p<0.001). The adjusted estimate of effectiveness was 67% (95% CI: 24%, 86%) for all patients and 64% (95% CI: 8%, 86%) in those with an indication for vaccination (persons age 60 or older or with major chronic conditions). Having received both the 2010-2011 seasonal influenza vaccine and the 2009-2010 pandemic influenza vaccine provided 87% protection (95% CI: 30%, 98%) as compared to those not vaccinated. CONCLUSION: The 2010-2011 seasonal influenza vaccine had a moderate protective effect in preventing laboratory-confirmed influenza.

Effectiveness of the 7-valent pneumococcal conjugate vaccine: a population-based case-control study.

BACKGROUND: The 7-valent pneumococcal conjugate vaccine (PCV7) has shown high efficacy in preventing invasive pneumococcal disease (IPD) caused by vaccine serotypes. We aimed to assess the overall effectiveness of PCV7 against IPD in Navarra, Spain. METHODS: All children aged <5 years who were diagnosed with IPD during the period 2001-2005 (n=85) and 5 control subjects per case patient (n=425), individually matched by birth date and birth hospital, were analyzed. Vaccination records were obtained from the regional immunization registry. Conditional logistic regression was used to estimate odds ratios. RESULTS: Eighteen case patients (21%) and 114 control subjects (27%) had received >or=1 dose of PCV7. PCV7 serotypes were responsible for 34 (51%) of the cases in unvaccinated children. The overall effectiveness for case prevention was 31% (odds ratio, 0.69; 95% confidence interval, 0.37-1.27). In a separate analysis, vaccination with PCV7 was 88% effective in preventing IPD due to vaccine serotypes (odds ratio, 0.12; 95% confidence interval, 0.02-0.91) and was associated with a higher risk of IPD due to nonvaccine serogroups (odds ratio, 6.16; 95% confidence interval, 1.63-23.3). CONCLUSIONS: These data reveal a higher risk of IPD caused by non-PCV7 serogroups among vaccinated children. Consequently, the overall effectiveness of PCV7 for IPD prevention may be greatly reduced.

[Invasive pneumococcal disease in children younger than 5 years in Navarra, Spain (2000-2005). Impact of the conjugate vaccine]. / Enfermedad neumocócica invasiva en la población menor de 5 años de edad de Navarra (2000-2005): impacto de la vacuna conjugada.

BACKGROUND AND OBJECTIVE: The 7-valent pneumococcal conjugate vaccine (PCV7) has been commercialized in Spain since June 2001. We aim to evaluate the impact of this vaccine in the incidence of invasive pneumococcal disease (IPD) in Navarre. POPULATION AND METHOD: The laboratories of microbiology of Navarre declare all the isolations of Streptococcus pneumoniae in samples of normally sterile corporal fluids. We analyzed the incidence of IPD in children younger than 5 years between weeks 41 of 2000 and 40 of 2005. RESULTS: The doses of PCV7 sold up to 2005 would provide a cover of 27% in children younger than 5 years, having assumed 4 dose schedules. In the 5 seasons, 103 cases of IPD were diagnosed. From the 2 first seasons (2000-2002) to the last one (2004-2005) a reduction of 69% in the incidence rate of IPD caused by vaccine serotypes was observed (from 33 to 10 cases by 100,000 children under 5 years; p = 0.003). Between those same periods the incidence of IPD caused by non-vaccine serotypes increased a 36% (from 42 to 57 by 100,000; p = 0.405). The global incidence of IPD diminished a 12% (from 77 to 67 by 100,000; p = 0.689). The percentage of cases that had received PCV7 increased until 45% in season 2004-2005 (p < 0.001). The meningitis and bacteraemic pneumonias supposed 42% of the IPD, without significant changes during the period (p = 0.442). CONCLUSIONS: Since the PCV7 was marketed the pattern of serotypes has changed, but the expected reduction in the total IPD incidence has not been achieved.

Household transmission of influenza A(H1N1)pdm09 in the pandemic and post-pandemic seasons.

BACKGROUND: The transmission of influenza viruses occurs person to person and is facilitated by contacts within enclosed environments such as households. The aim of this study was to evaluate secondary attack rates and factors associated with household transmission of laboratory-confirmed influenza A(H1N1)pdm09 in the pandemic and post-pandemic seasons. METHODS: During the 2009-2010 and 2010-2011 influenza seasons, 76 sentinel physicians in Navarra, Spain, took nasopharyngeal and pharyngeal swabs from patients diagnosed with influenza-like illness. A trained nurse telephoned households of those patients who were laboratory-confirmed for influenza A(H1N1)pdm09 to ask about the symptoms, risk factors and vaccination status of each household member. RESULTS: In the 405 households with a patient laboratory-confirmed for influenza A(H1N1)pdm09, 977 susceptible contacts were identified; 16% of them (95% CI 14-19%) presented influenza-like illness and were considered as secondary cases. The secondary attack rate was 14% in 2009-2010 and 19% in the 2010-2011 season (p=0.049), an increase that mainly affected persons with major chronic conditions. In the multivariate logistic regression analysis, the risk of being a secondary case was higher in the 2010-2011 season than in the 2009-2010 season (adjusted odds ratio: 1.72; 95% CI 1.17-2.54), and in children under 5 years, with a decreasing risk in older contacts. Influenza vaccination was associated with lesser incidence of influenza-like illness near to statistical significance (adjusted odds ratio: 0.29; 95% CI 0.08-1.03). CONCLUSION: The secondary attack rate in households was higher in the second season than in the first pandemic season. Children had a greater risk of infection. Preventive measures should be maintained in the second pandemic season, especially in high-risk persons.

[Impact of vaccination against influenza (H1N1) 2009 in Navarre: comparison of different scenarios]. / Impacto de la vacunación frente a la gripe (H1N1) 2009 en Navarra: comparación de diferentes escenarios.

BACKGROUND: A specific vaccination campaign against influenza A (H1N1) was conducted in 2009. We evaluated its impact in Navarre. METHODS: In the cohort of non-institutionalised population with chronic diseases covered by the Navarre Health Service (n=131,333), assuming 100% effectiveness from day 8 after administration of the pandemic vaccine, we estimated its impact on the prevention of influenza A (H1N1) 2009 cases and hospitalisations between weeks 47/2009 and 3/2010. RESULTS: In the nine weeks of the study, 973 cases of influenza syndrome were diagnosed (7 per 1000); but only 28% were due to influenza A (H1N1) 2009. In addition, there were 14 hospitalisations with virological confirmation (11 per 100,000). With 19% coverage with the pandemic vaccine (versus 40% with the seasonal vaccine), 7.7% of cases and 10.5% of hospitalisations were prevented during the study period. For each case prevented, 1092 doses of pandemic vaccine were administered, and for each hospitalisation avoided 15,021 doses were administered. If coverage had been the same as for the seasonal vaccine, it would have been possible to prevent 16.2% of cases and 22.2% of hospitalisations. If coverage had been double than for the seasonal vaccine and vaccination campaign had taken place two weeks earlier, it would have been possible to prevent 70.7% of cases and 68.0% of hospitalizations, with 261 doses needed to prevent one case and 6206 doses to avoid one hospitalisation. CONCLUSION: Despite the high effectiveness of the vaccine, its impact in Navarre has been minimal due to low coverage and late initiation of the vaccination campaign.

Effectiveness of the monovalent influenza A(H1N1)2009 vaccine in Navarre, Spain, 2009-2010: cohort and case-control study.

We defined a population-based cohort (596,755 subjects) in Navarre, Spain, using electronic records from physicians, to evaluate the effectiveness of the monovalent A(H1N1)2009 vaccine in preventing influenza in the 2009-2010 pandemic season. During the 9-week period of vaccine availability and circulation of the A(H1N1)2009 virus, 4608 cases of medically attended influenza-like illness (MA-ILI) were registered (46 per 1000 person-years). After adjustment for sociodemographic covariables, outpatient visits and major chronic conditions, vaccination was associated with a 32% (95% CI: 8-50%) reduction in the overall incidence of MA-ILI. In a test negative case-control analysis nested in the cohort, swabs from 633 patients were included, and 123 were confirmed for A(H1N1)2009 influenza. No confirmed case had received A(H1N1)2009 vaccine versus 9.6% of controls (p<0.001). The vaccine effectiveness in preventing laboratory-confirmed influenza was 89% (95% CI: 36-100%) after adjusting for age, health care setting, major chronic conditions and period. Pandemic vaccine was effective in preventing MA-ILI and confirmed cases of influenza A(H1N1)2009 in the 2009-2010 season.

Effectiveness of Jeryl Lynn-containing vaccine in Spanish children.

We evaluated the effectiveness of the Jeryl Lynn strain vaccine in a large outbreak of mumps in Navarre, Spain, 2006-2008. Each of the 241 cases of mumps occurring in children over 15 months of age born between 1998 and 2005 was compared with 5 controls individually matched by sex, birth date, district of residence and paediatrician. Vaccination history was obtained blindly from clinical records. Conditional logistic regression was used to obtain the matched odds ratios (ORs), and effectiveness was calculated as 1-OR. Some 70% of cases had received one dose of measles-mumps-rubella vaccine, and 24% had received two doses. Overall vaccine effectiveness was 72% (95% CI, 39-87%). Two doses were more effective (83%; 54-94%) than a single dose (66%; 25-85%). Among vaccinated children, risk was higher in those who had received the first dose after 36 months of age (OR=3.1; 1.2-8.4) and those who had received the second dose 3 or more years before study enrolment (OR=10.2; 1.5-70.7). Early waning of immunity in children after the second dose may contribute to reduced vaccine effectiveness for mumps prevention.

Impacto de la vacunación frente a la gripe (H1N1) 2009 en Navarra: comparación de diferentes escenarios / Impact of vaccination against influenza (H1N1) 2009 in Navarre: comparison of different scenarios

Fundamento: En 2009 se realizó una campaña de vacunación específica frente a la gripe (H1N1) 2009. El objetivo de este trabajo es evaluar su impacto en Navarra. Métodos: En la cohorte de población no institucionalizada de enfermos crónicos cubiertos por el Servicio Navarro de Salud (N=131.333), asumiendo una efectividad del 100% desde el octavo día tras la administración de la vacuna pandémica, estimamos su impacto en la prevención de casos y de hospitalizaciones por gripe (H1N1) 2009 entre las semanas 47/2009 y 3/2010. Resultados: En las nueve semanas del estudio se diagnosticaron 973 casos de síndrome gripal (7 por 1000). El 28% fueron debidos a gripe (H1N1) 2009. Además hubo 14 personas hospitalizadas con confirmación virológica (11 por 100.000). Con una cobertura de vacuna del 19% (frente al 40% de la estacional) se logró prevenir el 7,7% de los casos y el 10,5% de las hospitalizaciones durante el periodo de estudio. Se administraron 1.092 dosis de vacuna pandémica por cada caso prevenido y 15.021 dosis por cada hospitalización evitada. Con una cobertura idéntica a la de la vacuna estacional se habría conseguido prevenir 16,2% de los casos y 22,2% de las hospitalizaciones. Si se hubiese duplicado esta cobertura y adelantado la campaña de vacunación dos semanas se habrían prevenido 70,7% de los casos y 68,0% de los ingresos, necesitando 261 dosis para prevenir un caso y 6206 dosis para evitar una hospitalización. Conclusión: A pesar de la elevada efectividad de la vacuna su impacto en Navarra fue mínimo, debido a la baja cobertura y al inicio tardío de la campaña de vacunación(AU)

Background:Aspecific vaccination campaign against influenza A(H1N1) was conducted in 2009.We evaluated its impact in Navarre. Methods: In the cohort of non-institutionalised population with chronic diseases covered by the Navarre Health Service (n=131,333), assuming 100% effectiveness from day 8 after administration of the pandemic vaccine, we estimated its impact on the prevention of influenza A(H1N1)2009 cases and hospitalisations between weeks 47/2009 and 3/2010. Results: In the nine weeks of the study, 973 cases of influenza syndrome were diagnosed (7 per 1000); but only 28% were due to influenza A(H1N1)2009. In addition, there were 14 hospitalisations with virological confirmation (11 per 100,000).With 19% coverage with the pandemic vaccine (versus 40% with the seasonal vaccine), 7.7% of cases and 10.5% of hospitalisations were prevented during the study period. For each case prevented, 1092 doses of pandemic vaccine were administered, and for each hospitalisation avoided 15,021 doses were administered. If coverage had been the same as for the seasonal vaccine, it would have been possible to prevent 16.2% of cases and 22.2% of hospitalisations. If coverage had been double than for the seasonal vaccine and vaccination campaign had taken place two weeks earlier, it would have been possible to prevent 70.7% of cases and 68.0% of hospitalizations,with 261 doses needed to prevent one case and 6206 doses to avoid one hospitalisation. Conclusion: Despite the high effectiveness of the vaccine, its impact in Navarre has been minimal due to low coverage and late initiation of the vaccination campaign(AU)

Enfermedad neumocócica invasiva en la población menor de 5 años de edad de Navarra (2000-2005): impacto de la vacuna conjugada / Invasive pneumococcal disease in children younger than 5 years in Navarra, Spain (2000-2005). Impact of the conjugate vaccine

Fundamento y objetivo: Desde junio de 2001 se comercializa en España la vacuna neumocócica conjugada heptavalente (VNC7v). Nuestro objetivo ha sido evaluar su impacto en la incidencia de enfermedad neumocócica invasiva (ENI) en Navarra. Población y método: Los laboratorios de microbiología de Navarra declaran todos los aislamientos de neumococo en muestras de fluidos corporales normalmente estériles. Analizamos la incidencia de ENI en niños menores de 5 años entre las semanas 41 de 2000 y 40 de 2005. Resultados: Las dosis de VNC7v vendidas hasta 2005 permitirían alcanzar una cobertura del 27% en menores de 5 años, suponiendo 4 dosis por niño. Entre las 5 temporadas se diagnosticaron 103 casos de ENI. Comparando la incidencia de ENI en las 2 primeras temporadas (2000-2002) con la última (2004-2005), se observa un descenso del 69% en la tasa por serotipos vacunales (de 33 a 10 casos por 100.000 menores de 5 años; p = 0,003). Entre esos mismos períodos, la incidencia de ENI por serotipos no vacunales aumentó un 36% (de 42 a 57 por 100.000; p = 0,405). La incidencia global de ENI disminuyó un 12% (de 77 a 67 por 100.000; p = 0,689). El porcentaje de casos que habían recibido VNC7v aumentó hasta el 45% en la temporada 2004-2005 (p < 0,001). Las meningitis y neumonías bacteriémicas supusieron el 42% de las ENI, sin cambios significativos durante el período (p = 0,442). Conclusiones: Tras la comercialización de la VNC7v ha cambiado el patrón de serotipos, pero no se ha conseguido el descenso esperado de la incidencia global de ENI

Background and objective: The 7-valent pneumococcal conjugate vaccine (PCV7) has been commercialized in Spain since June 2001. We aim to evaluate the impact of this vaccine in the incidence of invasive pneumococcal disease (IPD) in Navarre. Population and method: The laboratories of microbiology of Navarre declare all the isolations of Streptococcus pneumoniae in samples of normally sterile corporal fluids. We analyzed the incidence of IPD in children younger than 5 years between weeks 41 of 2000 and 40 of 2005. Results: The doses of PCV7 sold up to 2005 would provide a cover of 27% in children younger than 5 years, having assumed 4 dose schedules. In the 5 seasons, 103 cases of IPD were diagnosed. From the 2 first seasons (2000-2002) to the last one (2004-2005) a reduction of 69% in the incidence rate of IPD caused by vaccine serotypes was observed (from 33 to 10 cases by 100,000 children under 5 years; p = 0.003). Between those same periods the incidence of IPD caused by non-vaccine serotypes increased a 36% (from 42 to 57 by 100,000; p = 0.405). The global incidence of IPD diminished a 12% (from 77 to 67 by 100,000; p = 0.689). The percentage of cases that had received PCV7 increased until 45% in season 2004-2005 (p < 0.001). The meningitis and bacteraemic pneumonias supposed 42% of the IPD, without significant changes during the period (p = 0.442). Conclusions: Since the PCV7 was marketed the pattern of serotypes has changed, but the expected reduction in the total IPD incidence has not been achieved

Elevada prevalencia de hipertrofia ventricular izquierda en pacientes con hipertensión arterial de larga evolución / High prevalence of left ventricular hypertrophy in patients with hypertension of long evolution

Fundamento y objetivo: La hipertrofia ventricular izquierda (HVI) es la enfermedad cardíaca más frecuente en hipertensos. El objetivo es conocer la prevalencia de HVI en población hipertensa de larga evolución tratada en el ámbito de atención primaria (AP), así como su perfil epidemiológico. Pacientes y método: Estudio descriptivo, transversal y multicéntrico, de 915 hipertensos que acudieron consecutivamente a consultas de AP y llevaban más de 5 años en tratamiento farmacológico. Se midió la presión arterial y se realizó anamnesis y registro de datos electrocardiográficos y bioquímicos. Se evaluó la HVI según criterios de Cornell y/o Sokolow-Lyon. Resultados: La población estudiada (el 63% mujeres) tiene una media de edad de 68,7 años; el 31,6% son diabéticos y el 37,5% tiene la presión arterial controlada. El 30,5% presenta criterios electrocardiográficos de HVI, con mayor prevalencia en mujeres; asimismo, las mujeres con HVI tienen una edad más avanzada. El 30% tiene antecedentes de enfermedad cardiovascular y la prevalencia de insuficiencia cardíaca es mayor en pacientes con HVI. El 54% está en politerapia antihipertensiva y no hay diferencias significativas en el tratamiento de los pacientes con y sin HVI. El 77% de los pacientes con HVI cumplen únicamente el criterio de Cornell; el 12%, sólo el de Sokolow-Lyon y el 11%, ambos criterios. Los pacientes que sólo tienen positividad para el criterio de Cornell se caracterizan por predominio del sexo femenino y mayor prevalencia de obesidad. Conclusiones: La prevalencia de HVI, valorada mediante criterios electrocardiográficos, es elevada en hipertensos de larga evolución, especialmente en mujeres. Es preciso insistir en la realización periódica de electrocardiogramas en hipertensos e incrementar el esfuerzo terapéutico

Background and objective: Left ventricular hypertrophy (LVH) is the most frequent manifestation of cardiac damage in hypertension. The objective of this study was to evaluate the prevalence of LVH in hypertensive patients of long evolution at Primary Care (PC) and to describe their epidemiological profile. Patients and method: 915 hypertensive patients treated for more than 5 years with antihypertensive drugs, who were atended in a consecutive way by de PC physicians, were evaluated in a multicentral and descriptive study. Clinical evaluation data together with electrocardiographic (EKG) and laboratory results were recorded. LVH was assessed by the Cornell and/or Sokolow-Lyon criteria. Results: Study population was characterized by a mean age of 68.7 years, 63% women, 31.6% diabetics, and 37.5% presented controlled blood pressure levels. 30.5% of them presented LVH criteria on EKG, being more prevalent among women, and on the other hand, women with LVH were of a greater age. 30% of patients presented history of cardiovascular disease and heart failure was more frequent among those with LVH. 54% were polymedicated with blood pressure lowering drugs, however there were no differences between groups of patients with and without LVH regarding their treatment. The Cornell criterion and the Sokolow-Lyon criterion alone were presented in a 77% and 12% of patients, respectively, and 11% of them were positive for both criteria. Patients with positivity for only the Cornell criterion were characterized by a greater prevalence of women and obesity. Conclusions: The prevalence of LVH assessed by EKG criteria is high among hypertensive population of long evolution. A greater effort is needed to guarantee a periodic EKG performance in hypertensive patients together with a therapeutic strategy improvement