Influenza outbreaks in nursing homes with high vaccination coverage in Navarre, Spain, 2011/12.

In the 2011/12 season, three influenza outbreaks were studied in nursing homes with high vaccination coverage in Navarre, Spain. Attack rates ranged from 2.9% to 67%. Influenza A/Stockholm/18/2011(H3N2) virus strain was isolated from the three outbreaks. Vaccination should be complemented with other hygiene measures in nursing homes. Early detection of influenza outbreaks in nursing homes can aid in their control.

[Incidence of influenza and influenza vaccine effectiveness in the 2004-2005 season]. / Incidencia de la gripe y efectividad de la vacuna antigripal en la temporada 2004-2005.

BACKGROUND: To quantify the incidence of flu in different groups of the population of Navarra in the 2004-2005 season, and to evaluate the effectiveness of anti-flu vaccination. METHODS: The analysis of influenza cases in the system of compulsory notificable diseases was complemented by the individualised notifications in the network of sentinel doctors that covers a population of 22,339 inhabitants. The coverage and effectiveness of the vaccine was studied. RESULTS: Vaccine coverage in (3)65 year olds reached 62%. The incidence of influenza was 42.6 cases per 1,000 inhabitants. It reached a maximum in mid-January, exceeding 750 weekly cases per 100,000 inhabitants and 1,900 cases per 100,000 children. The highest rate of influenza was observed in under-15 year olds (49.4 cases per 1,000 inhabitants) and the lowest in non-institutionalised (3)65 year olds (2.6 per 1,000 inhabitants), although it was higher in geriatric residences (62.1 per 1,000; p<0.0001). Seventy-nine percent of the cases from 5 to 64 years resulted in absenteeism from school or work. The flu virus was identified in 42/65 (65%) nasopharyngeal smears, 90% being influenza virus A(H3). The incidence of influenza was 3.08% in the unvaccinated and 0.45% in the vaccinated (p<0.001). The global effectiveness of the anti-flu vaccine was 65%, and in (3)65 years old it was 73%. CONCLUSION: Although its effectiveness is not total, the vaccine is the main measure for preventing influenza. The network of sentinel doctors provide useful information for the coordination of care and public health activities against flu.

Incidencia de la gripe y efectividad de la vacuna antigripal en la temporada 2004-2005 / Incidence of influenza and influenza vaccine effectiveness in the 2004-2005 season

Fundamento. Cuantificar la incidencia de gripe en distintos grupos de la población de Navarra en la temporada 2004-2005 y evaluar la efectividad de la vacunación antigripal.Métodos. El análisis de los casos de gripe del sistema de enfermedades de declaración obligatoria se ha complementado con las notificaciones individualizadas de la red de médicos centinela que atiende a una población de 22.339 habitantes. Se estudió la cobertura y efectividad de la vacuna. Resultados. La cobertura vacunal en Ž65 años alcanzó el 62%. La incidencia de gripe fue de 42,6 casos por 1.000 habitantes. Alcanzó el máximo a mediados de enero, superando 750 casos semanales por 100.000 habitantes y 1.900 casos por 100.000 niños. La mayor tasa de gripe se observó en menores de 15 años (49,4 casos por 1.000 habitantes) y la menor en Ž65 años no institucionalizados (2,6 por 1.000 habitantes), aunque fue mayor en residencias geriátricas (62,1 por 1.000; p<0,0001). El 79% de los casos de 5 a 64 años causó absentismo escolar o laboral. Se identificó el virus de la gripe en 42/65 (65%) frotis nasofaríngeos, siendo el 90% virus gripal A(H3). La incidencia de gripe fue del 3,08% en los no vacunados y del 0,45% en vacunados (p<0,001). La efectividad global de la vacuna antigripal fue del 65%, y en Ž65 años del 73%.Conclusión. Aunque su efectividad no es total, la vacuna es la principal medida para la prevención de la gripe. La red de médicos centinela aporta información útil para la coordinación de actividades asistenciales y de salud pública frente a la gripe

Background. To quantify the incidence of flu in different groups of the population of Navarra in the 2004-2005 season, and to evaluate the effectiveness of anti-flu vaccination. Methods. The analysis of influenza cases in the system of compulsory notificable diseases was complemented by the individualised notifications in the network of sentinel doctors that covers a population of 22,339 inhabitants. The coverage and effectiveness of the vaccine was studied. Results. Vaccine coverage in Ž65 year olds reached 62%. The incidence of influenza was 42.6 cases per 1,000 inhabitants. It reached a maximum in mid-January, exceeding 750 weekly cases per 100,000 inhabitants and 1,900 cases per 100,000 children. The highest rate of influenza was observed in under-15 year olds (49.4 cases per 1,000 inhabitants) and the lowest in non-institutionalised Ž65 year olds (2.6 per 1,000 inhabitants), although it was higher in geriatric residences (62.1 per 1,000; p<0.0001). Seventy-nine percent of the cases from 5 to 64 years resulted in absenteeism from school or work. The flu virus was identified in 42/65 (65%) nasopharyngeal smears, 90% being influenza virus A(H3). The incidence of influenza was 3.08% in the unvaccinated and 0.45% in the vaccinated (p<0.001). The global effectiveness of the anti-flu vaccine was 65%, and in Ž65 years old it was 73%. Conclusion. Although its effectiveness is not total, the vaccine is the main measure for preventing influenza. The network of sentinel doctors provide useful information for the coordination of care and public health activities against flu