Salleras L

Effectiveness of Pneumococcal Vaccination for Elderly People in Catalonia, Spain: A Case-Control Study

BACKGROUND Observational studies offer an approach to evaluating the effectiveness of vaccination programs. We evaluated the effectiveness of a 23-valent pneumococcal vaccination program for elderly people in Catalonia, Spain, in a matched-set case-control study. METHODS We identified 149 cases of invasive pneumococcal disease among patients aged > or =65 years who were hospitalized in 12 large hospitals in Catalonia during the period of 1 January 2001 through 31 March 2002. We selected 2 hospital control patients and 1 outpatient control subject for each case patient, matching on the basis of age and underlying medical conditions. We obtained their pneumococcal vaccination histories and used conditional logistic regression to determine effectiveness of vaccination. RESULTS Among all 149 cases of invasive pneumococcal disease, 131 (87.9%) were caused by vaccine or vaccine-related serotypes. In the adjusted analysis, overall effectiveness of vaccination against infections due to all serotypes was 70% (95% confidence interval [CI], 48%-82%). Among immunocompetent subjects with or without high-risk conditions, effectiveness of vaccination was 76% (95% CI, 51%-88%), but among immunocompromised subjects it was 50% (95% CI, -44% to 82%). Among subjects with infections due to vaccine or vaccine-related serotypes, effectiveness of vaccination was 72% (95% CI, 50%-85%) overall and 78% (95% CI, 50%-90%) in those who were immunocompetent, but it was only 46% (95% CI, -54% to 81%) in those who were immunocompromised. Overall effectiveness of vaccination was 65% (95% CI, 35%-81%) during the noninfluenza period. CONCLUSIONS Pneumococcal vaccination was effective in preventing invasive pneumococcal disease among all elderly persons in Catalonia. Effectiveness was greater in immunocompetent persons, most of whom had underlying high-risk conditions. The number of subjects was too small to determine whether vaccination was effective in those who were immunocompromised.

Effectiveness of a mass hepatitis A vaccination program in preadolescents.

A program of mass hepatitis A+B vaccination in preadolescents in schools was begun in the Catalonia in the last quarter of 1998. This study investigated the impact of the program by comparing the incidence of hepatitis A in vaccinated and unvaccinated cohort. The greatest reduction of the incidence rate of hepatitis A was observed in the 10-14 years age group, from 10.3 per 100000 persons-year in the period 1996-1998 to 1.8 per 100000 persons-year in the period 1999-2001. The global incidence decreased from 6.2 to 2.6 per 100000 persons-year. After analysis of cases occurring in the vaccinated and non vaccinated cohort, the effectiveness of the vaccination program was estimated at 97.0% (95% CI: 78.6-99.6).

Prevalencia del tabaquismo en Cataluña, 1982-1998: una perspectiva de género

Fundamento Describir la evolucion del habito tabaquico en la poblacion catalana entre 1982 y1998, a partir de un analisis de perspectiva de genero. Sujetos y metodo Se incluyeron datos de las encuestas llevadas a cabo por el Departament deSanitat i Seguretat Social en 1982, 1986, 1990, 1994 y 1998. Se analizaron el «status» defumador, el numero de cigarrillos diarios fumados, la edad y el sexo, asi como variables relacionadascon el tipo de tabaco fumado, la edad de inicio y la duracion del habito. Los resultadosse presentan como proporciones con sus intervalos de confianza del 95% y como medias consus desviaciones estandar. Resultados La prevalencia global del habito tabaquico en la poblacion de 15-64 anos se mantieneestable entre 1982 y 1998 (variacion porcentual de –1,1%) y se situa en un 37,5% defumadores actuales en 1998. En las mujeres, la prevalencia se incrementa un 53,5% durantedicho periodo y alcanza el 30,7% en 1998. En los varones se reduce un 23,8% y alcanza el44,4%. Entre 1994 y 1998 se rompe la tendencia decreciente que se habia producido hastaentonces en los jovenes de ambos sexos. En 1998, el 26,1% de las mujeres fuma tabaco«light» frente a un 10,4% de los varones; las mujeres fuman una media de 13,8 (8,8) cigarrillosdiarios frente a la media de 19,7 (12,6) cigarrillos que fuman los varones; la media de duraciondel habito entre las mujeres es de 13,9 (10,1) anos mientras que en los varones es de22,6 (16,0). Conclusiones Hasta el ano 1998, la prevalencia del habito tabaquico en Cataluna se mantuvoelevada a pesar de producirse una disminucion importante de la masculina. La situacion fueparticularmente desfavorable para los jovenes de ambos sexos y las mujeres, cuyo habito tabaquicopresenta caracteristicas especificas.

An outbreak of food poisoning due to a genogroup I norovirus.

Norovirus infection is associated with approximately 90% of epidemic non-bacterial acute gastroenteritis. The objective of this study is to describe an outbreak of norovirus genogroup I gastroenteritis which affected workers in a hospital and was attributed to food prepared by an infected food handler. Forty cases were detected, of whom 80% were interviewed. The index case was the cook employed in the hospital cafeteria. The following symptoms were observed: abdominal pain in 90.6%, vomiting in 71.9%, diarrhoea in 71.9%, general indisposition in 62.5%, headaches in 53.1% and fever in 32.4% of cases. The initial symptoms were abdominal pain in 37% and vomiting in 28%. Of the 14 samples analysed by RT-PCR, 12 (86%) were positive for a genogroup I norovirus. After sequencing the strain was identified as genotype Desert Shield. Many of the foodstuffs consumed were made by hand, favouring transmission from the index case to the cafeteria users.

Immunogenicity and reactogenicity of the adult tetanus-diphtheria vaccine. How many doses are necessary?

The immunogenicity and reactogenicity of the tetanus-diphtheria adult type vaccine was compared in two groups: group I (n = 201, 18-30 years old, presumably vaccinated with the DTP vaccine) and group II (n = 147, > or = 45 years old, without vaccination antecedents). Before vaccination, the seroprotection levels for tetanus were 90.5% (group I) and 30.6% (group II). These rose to 99.5% and 81.7%, respectively, after administration of one vaccine dose. For diphtheria, prevaccination seroprotection levels were 38.3% (group I) and 19.0% (group II). These rose to 85.8% and 65.7%, respectively, after vaccination. The logistic regression analysis showed an association between antibody titre and age. In group II, 3 doses of Td vaccine were needed to reach titres similar to those achieved in group I with a single dose. Stated reactogenicity was greater in: young subjects, women, those with higher titres of tetanus antibodies and those receiving other vaccines simultaneously. These results confirm the need for vaccination schedules adapted to the characteristics of each population age-group.

Dramatic decline of serogroup C meningococcal disease in Catalonia (Spain) after a mass vaccination campaign with meningococcal C conjugated vaccine

In the last quarter of the year 2000, the meningococcal C conjugated vaccine was incorporated into the routine vaccination schedule in Catalonia (at 2, 4 and 6 months). In addition a vaccination campaign was carried out in children <6 years of age, with a coverage of 96.2%. The effectiveness of the vaccination in this age group during 2001 and the first 28 weeks of 2002 was 100% (94.27-100%). A vaccination campaign has been carried out in 6-19-year olds during 2001 and 2002, with a coverage rate of 23.5% in the year 2001. In this age group a reduction in disease incidence was seen in the 2000-2001 season, but not in the following one.

Prevalencia y factores asociados a la presencia de esteatosis hepática en varones adultos aparentemente sanos

Fundamento El consumo de alcohol es uno de los factores que se asocian a esteatosis hepatica, perola contribucion de este consumo asi como de otros factores no esta suficientemente aclarada,particularmente en la poblacion aparentemente sana. Por este motivo el objetivo de este estudio fueevaluar la prevalencia y factores asociados a la presencia de esteatosis hepatica diagnosticadamediante ecografia. Sujetos Y metodos A 1.801 trabajadores varones aparentemente sanos (limites de edad: 18-60 anos)se les efectuo una exploracion fisica completa y analitica que incluyo el antigeno de superficie delvirus de la hepatitis B (HBsAg) y los anticuerpos frente al virus de la hepatitis C (anti-VHC). Todos lossujetos fueron interrogados sobre el consumo de alcohol y se les practico una ecografia abdominal,estableciendose el diagnostico de esteatosis hepatica segun criterios ecograficos. Resultados Un total de 88 sujetos tenian HBsAg, anticuerpos anti-VHC o una exploracion ecograficainsuficiente, por lo que fueron excluidos del estudio. De los 1.713 casos restantes, 236 tenianesteatosis (13,8%; 12,2–15,4). El analisis mediante regresion logistica determino la edad (OR: 1,04;IC del 95%: 1,03–1,05), la ingesta diaria de alcohol (superior a 40 g) (2,19; 1,81–2,65), los valoresde gamma-glutamiltransferasa superiores a 40 U/l (3,51; 2,95–4,18), el indice de masa corporalsuperior a 30 (3,87; 3,2–4,66) y la glucemia superior a 120 mg/dl (2,69; 1,85–3,90) como losfactores asociados a esteatosis hepatica. La esteatosis hepatica tambien se diagnostico en el 8,8% delos pacientes sin obesidad, hiperglucemia o hipercolesterolemia. Cuando se excluyeron los pacientescon obesidad, hiperglucemia, o hipercolesterolemia, el analisis de regresion confirmo la edad, elconsumo de alcohol y el aumento de gamma-glutamiltransferasa como factores independientesasociados a la presencia de esteatosis. Conclusiones La edad, el consumo de alcohol, la obesidad y el aumento de los valores de glucemia,colesterol y gamma-glutamiltransferasa son los principales factores asociados a la presencia deesteatosis hepatica en la poblacion adulta del sexo masculino, aparentemente sana.

Prevalence of Neisseria meningitidis carriers in the school population of Catalonia, Spain.

The aim of this study was to determine the prevalence of healthy Neisseria meningitidis pharyngeal carriers in a representative sample of the Catalonian school population, as well as its associated factors. The sample was divided into age groups: < or = 5, 6-7 and 13-14 years old. Parents were given a questionnaire to collect information on sociodemographic and epidemiological variables. Oropharyngeal swabs were collected with a cotton-tipped swab in an Amies transport medium and cultured on Thayer Martin plates at 35 degrees C in 5% CO2. The isolates were serogrouped and sero/subtyped. Of the 1406 children studied, 75 (5.34%) meningococcal carriers were detected: 63 B (4.5%), 9 non groupable (0.7%), 2 29E (0.1%) and 1X (0.07%). No serogroup C meningococci were found in this study, probably due to the high A+C vaccination coverage of up to 68.9% in children 6-7 years old. Bivariate analysis identified six statistically significant risk factors for meningococcal carriage: increasing age, recent upper respiratory tract infection, previous antibiotic treatment, number of students in the class, size of the classroom and social class. Multivariate analysis found that only age and previous antibiotic treatment remained statistically significant when the other factors were controlled.

The case-fatality rate of meningococcal disease in Catalonia, 1990-1997.

The objective was to analyse the case-fatality rate (CFR) of meningococcal disease (MD) in Catalonia, Spain. A retrospective study was carried out. Clinical histories of cases of MD reported for the period 1990–1997 in Catalonia were reviewed. For all cases, the variables gender, age, clinical type, y of presentation, province, phenotype and death by meningococcal disease were collected. The association between death and the other variables was studied by bivariate and unconditional logistic regression analysis. In the 2343 cases studied there were 146 deaths (6.2%) due to meningococcal disease. The CFR was higher in females (OR: 1.5, 95%CI: 1.1–2.1), in the 20 to 49 y (OR: 2.4, 95%CI: 1.2–4.9) and≥50 y (OR: 5.3, 95%CI: 2.8–10.1) age groups, in cases with septicaemia (OR: 2.4, 95%CI: 1.6–3.5), in the cases produced by serogroup A (OR: 4.7, 95%CI: 1.0–23.4) and in cases occurring during 1993 (OR: 2.1, 95%CI: 1.1–4.1) or in the province of Lleida (OR: 2.9, 95%CI: 1.2–7.2). In the multivariate analysis, death was associated with the 20–49 y age group (OR: 3.9, 95% CI: 1.8–8.4), the≥50 y age group (OR: 7.3, 95%CI: 3.6–14.7), septicaemia (OR: 3.1; 95%CI: 2.0–4.7) and residing in the province of Lleida (OR: 3.2; 95%CI: 1.2–8.5). The CFR of meningococcal disease in Catalonia was not associated with the emergent phenotype C:2b:P1.2,5 strain, which caused an outbreak in other regions of Spain.

Eficacia protectora de las vacunas y efectividad de las vacunaciones: introducción a la medición de la protección directa e indirecta

Resumen Se definen los conceptos de eficacia protectora vacunal (valor protector de una vacuna aplicada en condiciones ideales) y de efectividad de la vacunacion (valor protector de una vacunacion aplicada en las condiciones habituales de la practica clinica o de los programas de salud publica), y se describen los metodos de evaluacion de estos dos parametros. La eficacia protectora se evalua siempre mediante estudios experimentales (ensayos clinicos controlados y ensayos comunitarios aleatorizados). La evaluacion de la efectividad de la vacunacion se realiza mediante estudios epidemiologicos observacionales (normalmente de cohortes y de casos y controles). Los ensayos clinicos controlados y los estudios de casos y controles y de cohortes miden solo la proteccion directa conferida por la vacuna o la vacunacion. Para la evaluacion de la proteccion indirecta, hay que recurrir a los ensayos comunitarios aleatorizados por clusters (grupos de poblacion) o bien a los estudios descriptivos poblacionales que evaluan el impacto de los programas de vacunaciones.