ABSTRACT
La incorporación de la vacuna conjugada antineumocóc-cica 10 valente (PCV10) en lactantes en Chile el año 2011 ha permitido reducir las hospitalizaciones y muertes por neumonía en este grupo etario. Sin embargo, se ha observado desde entonces un aumento progresivo de los aislados de Streptococcus pneumoniae del serotipo 19A no incluido en la vacuna en uso (de < 5% del total de cepas recibidas en el Laboratorio de Referencia Nacional del Instituto de Salud Pública para vigilancia de infecciones invasores causadas por S. pneumoniae hasta el año 2010, a 12-23% en los años 2014-2015). En lactantes, el serotipo 19A representaba 4 a 8% de los aislados en la era pre vacuna, porcentaje que se incrementa a 25% el 2014. Este aumento ha ocurrido en dos terceras partes de las regiones administrativas del país. Cepas del serotipo 19A de pacientes menores de 5 años, muestran 25% de resistencia a penicilina para aislados extra-meníngeos y casi 100% para aislados de meningitis. El análisis genético de las cepas del serotipo 19A ha demostrado que 48% pertenecen al complejo clonal 320 de carácter pandémico y asociado a resistencia antimicrobiana. Además, casi todas las infecciones invasoras por serotipo 19A en niños se han dado en pacientes con esquema completo de vacunación PCV10. Los cambios epidemiológicos presentados indican la emergencia de infecciones invasoras por el serotipo 19A y la necesidad de controlar este problema con el cambio de la vacuna PCV10 a la vacuna PCV13 que contiene el serotipo 19A.
Inclusion of the 10-valent pneumococcal conjugated vaccine (PCV10) in the Chilean infant vaccination Program in 2011 was followed by a reduction of hospital admissions and pneumonia-related deaths in this age group. However, a progressive increase of serotype 19A pneumococcal isolates (not included in PCV10) has been observed. According to the analysis of pneumococcal strains performed by the national reference laboratory of the Institute of Public Health as part of a national surveillance on invasive pneumococcal infections, the relative proportion of serotype 19A isolates increased from <5% before 2010 to 12-23% in years 2014-2015. Serotype 19A represented 4-8% of the isolates in the pre-vaccine era among children less than 2 years, increasing to 25% during 2014. This increase has been documented in two-thirds of the national territory. Aimong children <5 years of age, 25% of 19A serotype isolates from non-meningeal infections were penicillin resistant wheras from meningeal infections near 100% were penicillin resistant. Genetic analysis indicates that 48% of these 19A strains belong to clonal complex 320, recognized for its pandemic potential and high antimicrobial resistance. Among children, most invasive infections secondary to serotype 19A have occurred in patients fully vaccinated with PCV10. These epidemiological changes indicate an increase in invasive pneumococcal infections by serotype 19A in Chile and the need to control this problem by changing the current PCV10 for the PCV13 vaccine containing serotype 19A.
Subject(s)
Humans , Child , Pneumococcal Infections/prevention & control , Streptococcus pneumoniae/classification , Vaccination/standards , Pneumococcal Vaccines/therapeutic use , Advisory Committees/standards , Chile , Drug Resistance, Bacterial , SerogroupABSTRACT
Invasive pneumococcal disease (IPD) remains as an important cause of morbidity in the world and in our country, while in Chile the incidence has decreased after the incorporation of the 10 valent pneumococcal conju-gate vaccine, in the routine infant inmunization schedule (EPI). One of the expected effects of the program after vaccination with 10-valent pneumococcal vaccine is the likely replacement serotype phenomenon that means the presence of ENI caused by serotypes not included in the vaccine. In this context, we present the case of a child with pneumococcal meningitis caused by serotype 19 A of fatal course. The occurrence of ENI in a later stage of pneumococcal vaccine incorporation in Chile reinforces the importance of active surveillance, in order to know in detail the impact of vaccination, distribution of circulating serotypes and their correlation with the different clinical disease and their severity.
La enfermedad neumocóccica invasora (ENI) sigue siendo una causa importante de morbilidad en el mundo y en nuestro país, si bien en Chile la incidencia ha disminuido luego de la incorporación de la vacuna neumocóccica conjugada 10-valente al Programa Nacional de Inmunizaciones (PNI). Uno de los efectos esperables luego de la vacunación programática con la vacuna antineumocóccica 10-valente es el probable fenómeno de reemplazo, que corresponde a la presencia de ENI por serotipos no incluidos en la vacuna. En este contexto, se presenta el caso de un pre-escolar con meningitis neumocóccica causada por el serotipo 19 A, de curso fatal. La presencia de casos de ENI en una etapa posterior a la implementación de la vacuna anti-neumocóccica en el PNI de Chile, demuestra la importancia de realizar una vigilancia activa, con el objetivo de conocer en forma detallada el impacto de la vacunación, la distribución de los serotipos circulantes y su correlación con los diferentes cuadros clínicos y su evolución.
Subject(s)
Child, Preschool , Humans , Male , Meningitis, Pneumococcal/diagnosis , Streptococcus pneumoniae/genetics , Fatal Outcome , Meningitis, Pneumococcal/drug therapy , Pneumococcal Vaccines/immunology , Streptococcus pneumoniae/immunology , Streptococcus pneumoniae/isolation & purificationABSTRACT
The use of pneumococcal vaccine plays an important role for prevention of invasive pneumococcal disease (IPD). However, introducing the pneumococcal vaccine into the national immunization program (NIP) is complex and costly. The strategy of progressively integrating the pneumococcal conjugate vaccine (PCV) into the NIP in Taiwan provides valuable experience for policy makers. The 7-valent PCV (PCV7) was first available in Taiwan in late 2005. PCV7 was first provided free to children with underlying diseases, those in vulnerable socioeconomic status, and those with inadequate health care resources. The catch-up immunization program with the 13-valent PCV was launched in 2013 and the national pneumococcal immunization program was implemented in 2015. Children aged 2-5 years had the highest incidence of IPD among pediatric population in Taiwan. Although the incidence of IPD caused by PCV7 serotypes has declined, the overall incidence of IPD remained high in the context of PCV7 use in the private sector. A surge of IPD caused by serotype 19A occurred, accounting for 53.6% of IPD cases among children aged < or = 5 years in 2011-2012. After the implementation of the national pneumococcal immunization program, serogroup 15 has become the leading serogroup for IPD in children. Continued surveillance is necessary to monitor the serotype epidemiology in Taiwan.
Subject(s)
Child , Humans , Administrative Personnel , Delivery of Health Care , Epidemiology , Immunization Programs , Incidence , Pneumococcal Vaccines , Private Sector , Social Class , TaiwanABSTRACT
Streptococcus pneumoniae is a major cause of serious invasive diseases in children, especially in young infants, but seven-valent pneumococcal conjugate vaccine (PCV7) is believed to prevent invasive pneumococcal pneumonia and meningitis in young children. However, recently, the incidence of non-PCV7 serotype has increased after PCV7 vaccination. A 14-month-old female patient presented at our emergency room with mental change and lethargy. Three days previously, she had developed fever and vomiting. After being admitted, she rapidly progressed to coma and brain death despite prompt and extensive supportive treatment. She expired 20 days after admission with a final diagnosis of pneumococcal 19A (non-PCV7 serotype) meningoencephalitis despite having received PCV7 (Prevenar(R)) vaccinations on three occasions. The author reports this first fatality due to pneumococcal 19A meningoencephalitis in Korea and provides a brief review of the literature.