Estudio epidemiológico de portadores nasofaríngeos de Streptococcus pneumoniae en niños en la comunidad autónoma de Murcia / Epidemiological study of nasopharyngeal carriers of Streptococcus pneumoniae in children in Murcia region

INTRODUCCIÓN Y OBJETIVOS: Streptococcus pneumoniae es un patógeno para el ser humano que precisa de colonización nasofaríngea previa para causar enfermedad. Realizamos un estudio epidemiológico de portadores nasofaríngeos de neumococo en niños sanos en Murcia, tras la introducción de la vacuna neumocócica conjugada heptavalente (VCN7) y ante la inmediata comercialización de las nuevas vacunas con el objetivo de conocer, en nuestro ámbito geográfico, la influencia de la vacunación y de otros factores sobre el estado de portador y los diferentes serotipos circulantes. MÉTODOS: En verano de 2009 e invierno de 2010 realizamos un estudio multicéntrico en 60 consultas de atención primaria, recogiéndose una muestra nasofaríngea y cumplimentándose una encuesta epidemiológica en 1.562 niños de 1 y 4años. De las 1.562 muestras nasofaríngeas se obtuvieron 489 neumococos, habiéndose podido serotipar 343 (72% de los aislados). RESULTADOS: El 31,3% (489/1.562) de los niños eran portadores. El 61,7% (964/1.562) de los pacientes incluidos habían recibido al menos una dosis de la VCN7. El 12,8% (44/343) de los serotipos identificados eran serotipos vacunales. Fueron factores protectores independientes de colonización: el periodo de verano en todas las edades, la vacunación en el total de los niños (OR: 0,73; IC 95%: 0,56-0,93; p = 0,010) y en niños de 1año (OR: 0,6; IC 95%: 0,42-0,84; p = 0,002) y haber tomado antibióticos en el último mes en el total de la población (OR: 0,69; IC95%: 0,50-0,96). Por el contrario, para todo el grupo, la escolarización (OR: 1,85; IC95%: 1,27-2,18; p = 0,001), el número de hermanos (OR: 1,31; IC 95%: 1,01-0,91) y la exposición al tabaco (OR: 1,33; IC 95%: 1,02-1,73) fueron factores de riesgo. Los serotipos 6A, 19A, 23B, 15A/B, 11A, 14, 23A/F, 3 y 19F fueron los más prevalentes. CONCLUSIONES: La proporción de serotipos vacunales encontrados fue baja, persistiendo el 14, el 23F y el 19F. Hallamos una alta prevalencia de serotipos 6A y 19A. El periodo estival, la vacunación y la administración previa de antibióticos demostraron ser protectores de la colonización; y la escolarización, el hábito tabáquico y el número de hermanos, facilitadores de la misma

BACKGROUND AND OBJECTIVES: Streptococcus pneumoniae is a human pathogen that requires prior nasopharyngeal colonization to cause disease. An epidemiological study was conducted on nasopharyngeal carriers of pneumococci in healthy children in Murcia after the introduction of the VCN7, and immediately before the marketing of new vaccines, with the aim of determining the influence of vaccination in our geographic area, and other factors in relation to the state of being a carrier, and the different circulating serotypes. METHODS: A multicentre study was conducted in in 60 primary care health centres in summer 2009 and winter of 2010. A nasopharyngeal swab was collected, and an epidemiological study was carried out on 1562 children aged 1 and 4 years. Of the 1562 nasopharyngeal samples, pneumococci were found in 489 of them, with 343 of them able to be serotyped (70.2%). RESULTS: The prevalence of carriers was 31.3%. Of the patients included, 61.7% (964/1562) had received at least one dose of VCN7. Only 12.8% of the identified serotypes were vaccine serotypes. The independent protective factors against colonization were; Summer time in all age groups, previous vaccination in all the children (OR: 0.75; 95%CI: 0.56-0.93]; P = .01, and in 1-year-olds (OR: 0.6; 95% CI: 0.42-0.84; P =.002), and had taken antibiotics in the last month in the total cohort [OR: 0.69; 95% CI: 0.50-0.96). On the other hand, attendance at school or day-care centre (OR: 1.85; 95% CI: 1.27-2.18; P=.001), number of siblings (OR: 1.3; 95% CI: 1.01-1.91), and passive tobacco smoke exposure (OR: 1.33; 95%CI: 1.02-1.73), were colonization risk factors. The serotypes 6A, 19A, 23B, 15A/B, 11A, 14, 23A/F, 3 y 19F were the most prevalent. CONCLUSIONS: A low proportion of SV was found, with 14, 23F and 19F are persisting. A high prevalence of serotypes 6A and 19A was found. Summer time, vaccination, and the prior administration of antibiotics proved to be protective against colonization, whereas schooling, smoking, and siblings contributed to it

[Epidemiological study of nasopharyngeal carriers of Streptococcus pneumoniae in children in Murcia region]. / Estudio epidemiológico de portadores nasofaríngeos de Streptococcus pneumoniae en niños en la comunidad autónoma de Murcia.

BACKGROUND AND OBJECTIVES: Streptococcus pneumoniae is a human pathogen that requires prior nasopharyngeal colonization to cause disease. An epidemiological study was conducted on nasopharyngeal carriers of pneumococci in healthy children in Murcia after the introduction of the VCN7, and immediately before the marketing of new vaccines, with the aim of determining the influence of vaccination in our geographic area, and other factors in relation to the state of being a carrier, and the different circulating serotypes. METHODS: A multicentre study was conducted in in 60 primary care health centres in summer 2009 and winter of 2010. A nasopharyngeal swab was collected, and an epidemiological study was carried out on 1562 children aged 1 and 4 years. Of the 1562 nasopharyngeal samples, pneumococci were found in 489 of them, with 343 of them able to be serotyped (70.2%). RESULTS: The prevalence of carriers was 31.3%. Of the patients included, 61.7% (964/1562) had received at least one dose of VCN7. Only 12.8% of the identified serotypes were vaccine serotypes. The independent protective factors against colonization were; Summer time in all age groups, previous vaccination in all the children (OR: 0.75; 95%CI: 0.56-0.93]; P=.01, and in 1-year-olds (OR: 0.6; 95%CI: 0.42-0.84; P=.002), and had taken antibiotics in the last month in the total cohort [OR: 0.69; 95%CI: 0.50-0.96). On the other hand, attendance at school or day-care centre (OR: 1.85; 95%CI: 1.27-2.18; P=.001), number of siblings (OR: 1.3; 95%CI: 1.01-1.91), and passive tobacco smoke exposure (OR: 1.33; 95%CI: 1.02-1.73), were colonization risk factors. The serotypes 6A, 19A, 23B, 15A/B, 11A, 14, 23A/F, 3 y 19F were the most prevalent. CONCLUSIONS: A low proportion of SV was found, with 14, 23F and 19F are persisting. A high prevalence of serotypes 6A and 19A was found. Summer time, vaccination, and the prior administration of antibiotics proved to be protective against colonization, whereas schooling, smoking, and siblings contributed to it.