Geographical migration and fitness dynamics of Streptococcus pneumoniae.

Streptococcus pneumoniae is a leading cause of pneumonia and meningitis worldwide. Many different serotypes co-circulate endemically in any one location1,2. The extent and mechanisms of spread and vaccine-driven changes in fitness and antimicrobial resistance remain largely unquantified. Here using geolocated genome sequences from South Africa (n = 6,910, collected from 2000 to 2014), we developed models to reconstruct spread, pairing detailed human mobility data and genomic data. Separately, we estimated the population-level changes in fitness of strains that are included (vaccine type (VT)) and not included (non-vaccine type (NVT)) in pneumococcal conjugate vaccines, first implemented in South Africa in 2009. Differences in strain fitness between those that are and are not resistant to penicillin were also evaluated. We found that pneumococci only become homogenously mixed across South Africa after 50 years of transmission, with the slow spread driven by the focal nature of human mobility. Furthermore, in the years following vaccine implementation, the relative fitness of NVT compared with VT strains increased (relative risk of 1.68; 95% confidence interval of 1.59-1.77), with an increasing proportion of these NVT strains becoming resistant to penicillin. Our findings point to highly entrenched, slow transmission and indicate that initial vaccine-linked decreases in antimicrobial resistance may be transient.

The pneumococcal conjugate vaccine had a sustained effect on Swedish children 8 years after its introduction.

AIM: The pneumococcal conjugate vaccine, which covered seven serotypes of Streptococcus pneumoniae (PCV7), was introduced in Stockholm, Sweden, in 2007. It was replaced by a 13-valent vaccine (PCV13) in 2011. We previously reported a decreased incidence of pneumonia and sinusitis among young children 4 years after the introduction of the PCV7. This study followed the incidence of pneumonia, sinusitis, mastoiditis and meningitis for four more years. METHODS: We studied validated hospital registry data covering children up to 17 years of age, who were hospitalised in the Stockholm region from 2003 to 2016, when the child population peaked at 485 687. All 11 115 cases diagnosed with pneumonia, coded as bacterial pneumonia, sinusitis, mastoiditis, bacterial meningitis or empyema, were identified. The controls had viral pneumonia or pyelonephritis. RESULTS: The incidence rates for children under 2 years of age hospitalised for sinusitis, mastoiditis and meningitis decreased significantly by 61%-79% during the eight-year post-vaccination period. Hospitalisations for bacterial pneumonia decreased by 19%-25% in the same age group. These changes were probably due to both the vaccines and changes in diagnosis routines. CONCLUSION: The effect of vaccination on children under 2 years of age was sustained 8 years after the introduction of the pneumococcal conjugate vaccines.

Predicted serotype-specific effectiveness of pneumococcal conjugate vaccines V114 and PCV20 against invasive pneumococcal disease in children.

BACKGROUND: Next-generation, higher-valency pneumococcal conjugate vaccines (PCVs), 15-valent PCV V114 and 20-valent PCV (PCV20), have been assessed by comparing their immune responses across serotypes shared with the 13-valent PCV (PCV13). Without efficacy or real-world vaccine effectiveness (VE) it becomes important to relate IgG titers to VE to aid in the interpretation of the immune response elicited by V114 and PCV20. METHODS: We estimated the protective antibody concentrations for each serotype in 7-valent PCV (PCV7) and PCV13 which were then used to predict the serotype-specific VE for each PCV7 and PCV13 non PCV7 serotype present in V114 and PCV20. RESULTS: The predicted effectiveness of V114 was comparable to PCV7 and PCV13 for 11 of the 13 shared serotypes (1, 4, 5, 6B, 7F, 9 V, 14, 18C, 19A, 19F, and 23F), with improved effectiveness against serotype 3 and decreased effectiveness against serotype 6A. PCV20 had predicted effectiveness comparable to PCV7 and PCV13 for 7 of the 13 shared serotypes (5, 6A, 7F, 9 V, 18C, 19F, and 23F), with decreased effectiveness against the remaining serotypes (1, 3, 4, 6B, 14, and 19A). CONCLUSIONS: Prediction of serotype-specific VE values suggests that V114 retains greater effectiveness than PCV20 toward most serotypes present in PCV7 and PCV13.

Pediatric pneumococcal conjugate vaccines (PCVs) first became available in 2000, when the seven-valent PCV (PCV7) was approved. Since then, PCV7 has been replaced by higher-valency vaccines, including the ten-valent (PCV10) and thirteen-valent (PCV13) vaccines and, more recently, fifteen- and twenty-valent vaccines (V114 and PCV20, respectively). The increase in valency provides broader serotype coverage against invasive pneumococcal disease (IPD) in children. However, IPD due to serotypes contained in PCV7 and PCV13 continue to be observed. In the current study, we used a previously published method to estimate the vaccine effectiveness of V114 and PCV20 in a US and Puerto Rican pediatric population that is recommended to receive a 3 + 1 dosing schedule.

Validation and comprehensive analysis of Streptococcus pneumoniae IgG WHO enzyme-linked immunosorbent assay in an Indian reference laboratory.

Monitoring serotype-specific IgG levels against pneumococci is crucial for assessing immunity, vaccine efficacy, and evaluating vaccination programs. The WHO ELISA for pneumococci is a standardized assay ensuring consistency in testing and comparability of results across laboratories. It involves a rigorous testing process to confirm accurate, precise and reliable detection of antibodies. We validated the protocol for 13 pneumococcal serotypes by assessing its specificity, reproducibility (coefficient of variation ≤15%), repeatability (coefficient of variation ≤20%), accuracy, lower limit of quantification, stability, and robustness. We found these parameters were within acceptable ranges and showed excellent performance. Our findings imply that the method employed is appropriate for evaluating 13 valent pneumococcal conjugate vaccine which is introduced in the national immunization program by comparing pre-and post-vaccination IgG response.

Understanding healthcare providers' preferred attributes of pediatric pneumococcal conjugate vaccines in the United States.

As higher-valent pneumococcal conjugate vaccines (PCVs) become available for pediatric populations in the US, it is important to understand healthcare provider (HCP) preferences for and acceptability of PCVs. US HCPs (pediatricians, family medicine physicians and advanced practitioners) completed an online, cross-sectional survey between March and April 2023. HCPs were eligible if they recommended or prescribed vaccines to children age <24 months, spent ≥25% of their time in direct patient care, and had ≥2 y of experience in their profession. The survey included a discrete choice experiment (DCE) in which HCPs selected preferred options from different hypothetical vaccine profiles with systematic variation in the levels of five attributes. Relative attribute importance was quantified. Among 548 HCP respondents, the median age was 43.2 y, and the majority were male (57.9%) and practiced in urban areas (69.7%). DCE results showed that attributes with the greatest impact on HCP decision-making were 1) immune response for the shared serotypes covered by PCV13 (31.4%), 2) percent of invasive pneumococcal disease (IPD) covered by vaccine serotypes (21.3%), 3) acute otitis media (AOM) label indication (20.3%), 4) effectiveness against serotype 3 (17.6%), and 5) number of serotypes in the vaccine (9.5%). Among US HCPs, the most important attribute of PCVs was comparability of immune response for PCV13 shared serotypes, while the number of serotypes was least important. Findings suggest new PCVs eliciting high immune responses for serotypes that contribute substantially to IPD burden and maintaining immunogenicity against serotypes in existing PCVs are preferred by HCPs.

Pediatric otitis media in Japan: A nationwide longitudinal study of the pre- and post-pneumococcal conjugate vaccine eras born in 2001 and 2010.

BACKGROUND: Otitis media (OM) is a prevalent respiratory disease in children and poses significant public health challenges due to its impact on child health and economic burdens. However, there have no nationwide epidemiological studies conducted in Japan. This study investigates the epidemiological trends of OM in Japan, taking into account the impact of the 7-valent pneumococcal conjugate vaccine (PCV7) introduction. METHOD: This study was retrospective cohort study using secondary data on the nationwide longitudinal birth cohort. This survey followed two cohorts born in 2001 (pre-PCV era) and 2010 (post-PCV era) until the age of 9. Every year, parents were surveyed about their children's health status, including occurrences of OM. The annual period prevalence and cumulative incidence of OM were assessed in this study, and the two cohorts were compared using a modified Poisson regression model adjusted environmental factors with the 2001 cohort as reference. RESULT: The study included 47,015 children from the 2001 cohort and 38,554 from the 2010 cohort. Peak annual period prevalence of OM varied by era. Cumulative incidence was 13.8 % for the 2001 cohort and 18.5 % for the 2010 cohort by 1.5 years of age and 28.9 % and 33.3 %, respectively, by 3.5 years of age. In particular, from the fourth survey onward, covering ages 2.5-3.5 years, a shift was observed from an increased risk to a decreased risk of OM. CONCLUSION: This nationwide longitudinal study emphasizes variations in OM epidemiology across Japan over time, with changes potentially influenced by the introduction of PCV7. In this study, due to the absence of individual PCV7 vaccination data, the effect of PCV7 was estimated based on the vaccination rate at the population level. The results suggest a notable decrease in the incidence of OM in later years, aligning with the increased uptake of PCV7.

Long-term effect of pneumococcal conjugate vaccines on invasive pneumococcal disease incidence among people of all ages from national, active, laboratory-based surveillance in South Africa, 2005-19: a cohort observational study.

BACKGROUND: In South Africa, 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2009 and 13-valent PCV (PCV13) was introduced in 2011, both in a two plus one schedule. We evaluated the ongoing effects of PCV on the prevention of invasive pneumococcal disease (IPD) over 15 years of sustained surveillance in South Africa before the COVID-19 pandemic. METHODS: We conducted national, active, laboratory-based surveillance for IPD among all ages in South Africa, including isolate serotyping and susceptibility testing. We fitted linear regression models with vaccine covariates to imputed IPD case counts each year by serotype and age to compare expected and actual IPD cases in 2019, which was the main outcome. Vaccine effects were set to zero to identify expected incidence after the introduction of PCV7 and PCV13. FINDINGS: From Jan 1, 2005, to Dec 31, 2019, surveillance identified 52 957 IPD cases. Among the 50 705 individuals with age data available, 9398 (18·5%) were infants aged younger than 2 years. Compared with expected case numbers (no vaccination) predicted using all available data, overall IPD rates among children younger than 2 years declined by 76·0% (percentage risk difference; 95% CI -79·0 to -72·8%) in 2019; notably, PCV7 and additional PCV13 serotype IPD rates declined by 95·5% (-97·0 to -93·4%) and 93·8% (-96·2 to-90·5%), respectively, whereas non-vaccine serotypes (NVTs) did not change significantly. Among adults aged 25-44 years, overall IPD declined by 50·4% (-54·2 to -46·3%), and PCV7 and additional PCV13 serotype IPD rates declined by 86·1% (-88·7 to -83·1%) and 77·2% (-80·9 to -73·0%), respectively, whereas NVTs increased by 78·5% (56·8 to 103·4%). Individuals aged older than 64 years also benefited from declines in IPD (-30·2%; -41·9 to -16·2%), but NVTs increased (234·9%; 138·1 to 379·4%). INTERPRETATION: We documented sustained direct and indirect benefits of PCV across age groups, and NVT increases in adults older than 24 years. Higher valency PCVs would have the added benefit of preventing this residual disease. FUNDING: National Institute for Communicable Diseases of the National Health Laboratory Service (South Africa) and US Agency for International Development Antimicrobial Resistance Initiative, US Centers for Disease Control and Prevention.

Streptococcus pneumoniae: distribution of serotypes and antimicrobial susceptibility in patients with cáncer / Streptococcus pneumoniae: distribución de serotipos y susceptibilidad antimicrobiana en pacientes con cancer

Abstract: Objective: To describe the distribution of pneumococcal serotypes causing infectious diseases in patients with hematological malignancies and solid tumors and their antimicrobial susceptibility before and after introduction of pneumococcal conjugate vaccine (PCV7) in Mexico. Materials and methods: Consecutive pneumococcal isolates from hospitalized patients from the SIREVA-network were serotyped using the Quellung reaction and antimicrobial susceptibility was performed using the broth microdilution method. Results: A total of 175 pneumococcal isolates were recovered, 105 from patients with hematological malignancies and 70 with solid tumors. Serotypes 19A (22.7%), 19F (20.4%), and 35B (17.7%) were the most frequent isolates in the first group and serotypes 3 (27.2%) and 19A (28.6%) in the second group. No decreased susceptibility to beta-lactams or TMP/SMX was observed after introduction of PCV7. Conclusions: An increase in non-vaccine types is observed without significate changes in antimicrobial susceptibility after introduction of PCV7.

Resumen: Objetivo: Describir la distribución de serotipos neumocócicos en pacientes con neoplasias hematológicas y tumores sólidos, así como la susceptibilidad antimicrobiana antes y después de la introducción de la vacuna conjugada contra neumococo (PCV7) en México. Material y métodos: Se tipificaron, mediante la reacción de Quellung, los aislamientos consecutivos en hospitales de la Red SIREVA-México. Se determinó la susceptibilidad antimicrobiana mediante microdilución en placa. Resultados: Se recuperaron 175 aislamientos, de los cuales 105 provenían de pacientes con neoplasias hematológicas y 70 con tumores sólidos. Los serotipos 19A (22.7%), 19F (20.4%) y 35B (17.7%) fueron los más frecuentes en el primer grupo y los serotipos 3 (27.2%) y 19A (28.6%) en el segundo. No se observó disminución de la resistencia a betalactámicos o TMP/SMX después de la introducción de PCV7. Conclusiones: Se observa un incremento de serotipos no vacunales, sin cambios significativos en la susceptibilidad antimicrobiana antes y después de la introducción de PCV7.

Bacteriemia oculta en niños atendidos en el Complejo Asistencial Dr. Sótero del Río: experiencia post vacuna neumocóccica conjugada / Occult bacteremia in Sótero del Río Hospital: experience after pneumococcal conjugated vaccine

Background: Occult bacteremia (OB) is one of the possible diagnoses of children younger than 3 years with fever without source in the emergency room. Objective: describe OB in the era after introduction of pneumococcal vaccine in Chile. Patients and Methods: Prospective descriptive review of data of children with possible OB diagnosis, referred from the emergency department between 2010-2013. Results: Possible OB was diagnosed on 391 patients. 233 had focus, mainly respiratory virus and urinary tract infection. On 158 patients, probable BO was diagnosed, 20 had proven OB from which 15 had positive blood culture for Streptococcus pneumoniae. From these, 7 were fully or partially vaccinated. The serotype was identified on 14 cases: 6 were PCV10 vaccine serotypes (none of them vaccinated), 2 were serotype related (both partially vaccinated) and 6 were non vaccine serotypes (partially or totally vaccinated). Discussion: It is necessary to improve diagnostic methods for respiratory viruses and urinary tract infections and try to expand coverage of pneumococcal conjugated vaccines in the pediatric population in order to reduce the risk of invasive pneumococcal disease in Chile.

Introducción: La bacteriemia oculta (BO) es uno de los diagnósticos que se plantean en los niños bajo 3 años de edad que se presentan con fiebre sin foco en el servicio de urgencia. Objetivo: Describir el diagnóstico de BO luego de la introducción de la vacunación universal para Streptococcus pneumoniae en Chile. Materiales y Métodos: Revisión descriptiva de seguimiento prospectivo de datos de niños con diagnóstico de BO posible derivados del SU entre 2010 y 2013. Resultados: Se diagnosticó BO posible en 391 pacientes. En 233 pacientes se encontró foco, siendo infecciones respiratorias virales e infección urinaria las más frecuentes. En 158 pacientes se diagnosticó BO probable, en 20 BO probada y 15 tuvieron hemocultivos positivos para S. pneumoniae. De estos últimos 7 estaban total o parcialmente vacunados. Se identificó serotipo en 14 casos: 6 serotipos vaccinales incluidos en PCV10 (ninguno vacunado), 2 serotipos relacionados (ambos parcialmente protegido) y 6 serotipos no vaccinales (parcial o totalmente vacunados). Discusión: Es necesario mejorar las técnicas diagnósticas de infecciones respiratorias virales e infección urinaria e intentar ampliar la cobertura de las vacunas neumocóccicas conjugadas en la población pediátrica, para reducir el riesgo de enfermedades neumocóccicas invasoras en Chile.

Efectos de la vacuna neumocócica conjugada (VCN7 y VCN13) en los niños turcos con enfermedad neumocócica invasiva: experiencia en un solo centro / The effects of pneumococcal conjugate vaccine (PCV7 and PCV13) on Turkish children with invasive pneumococcal disease: a single center experience

Introducción: Nuestro objetivo fue determinar los cambios en la incidencia de enfermedad neumocócica invasiva (ENI), la distribución de serotipos y patrones de resistencia antibiótica del Streptococcus pneumoniae en niños con ENI tras el período de vacunación (de 1 a 7 años) con vacuna neumocócica de 7 serotipos (VCN7) (2008) y de 13 serotipos (VCN13) (2011). Población y métodos: El estudio se realizó en 39 niños con ENI de 1 mes a 18 años de edad en Angora, Turquía. Se identificó Streptococcus pneumoniae en sangre, líquido cefalorraquídeo, líquido pleural, y otros tejidos y líquidos corporales estériles mediante procedimientos estándar. Se analizó la resistencia de cepas aisladas de S. pneumoniae a penicilina y ceftriaxona con la prueba de epsilometría (E-test). Los serotipos de las cepas se determinaron con la reacción de Quellung. Resultados: La incidencia anual de ENI disminuyó significativamente de 7,71 (intervalo de confianza --#91;IC--#93; del 95%: de 1,99 a 13,4) a 1,58 (IC del 95%: de 0,6 a 3,77; reducción del riesgo relativo= -79,5; p= 0,006) cada 100 000 habitantes de < 5 años de edad sin enfermedad preexistente. Durante todo el período del estudio, los serotipos en la VCN7 y en la VCN13 representaron el 27,8% y el 63,8% de las cepas aisladas, respectivamente. Los serotipos en la VCN13 correspondían al 81,8% de los casos de ENI en la era previa a la introducción de esta vacuna, y disminuyeron al 56% en los cuatro años posteriores. Las tasas de resistencia a penicilina y ceftriaxona (en el caso de la meningitis) fueron del 48,5% y el 9,1%, respectivamente. Conclusiones: Este estudio observó una disminución significativa en la incidencia de ENI después de la introducción de la VCN13.

Introduction. The aim of this prospective singlecenter study was to determine the changings in incidence of invasive pneumococcal disease (IPD), serotype distribution and the antimicrobial resistance patterns of S. pneumoniae in children with IPD after the period (1 to 7 years) of vaccination with PCV7 (2008) and PCV13 (2011). Population and methods. The study was conducted on 39 Turkish children with IPD between ages 1 month and 18 years in Ankara, Turkey. Streptococcus pneumoniae was identified using standard laboratory procedures from blood, cerebrospinal fluid (CSF), pleural fluid, and other sterile body fluids and tissues. S. pneumoniae isolates were tested for resistance to penicilin and ceftriaxone using the E-test methodology. Serotypes of the isolates were determined by Quellung reaction. Results. The overall annual incidence rate of IPD decreased significantly from 7.71 (95% CI, 1.99-13.4) to 1.58 (95% CI, 0.6-3.77; RRR= -79.5; p= 0.006) per 100 000 population among <5 years of age without underlying disease. During the overall study period, the PCV7-serotypes and PCV13-serotypes represented 27.8% and 63.8% of isolates, respectively. PCV13-serotypes made up 81.8% of cases of IPD in the pre-PCV13 era and decreased to 56% in the 4 years after PCV13. The penicillin and ceftriaxone (for meningitis) resistance rates were 48.5% and 9.1%, respectively. Conclusions. This is the first study about the changing pattern of the incidence of IPD in Turkish children after the implementation of the PCV7 and PCV13 in Turkish national vaccine schedule and a prominent decrease in incidence of IPD has seen after the implementation of PCV13.

Enfermedad neumoccócica invasora en recién nacidos, antes y después de la vacunación universal con vacuna conjugada 7 y 13 valente en Uruguay / Pneumococcal invasive disease in newborns before and after 7-valent and 13-valent universal pneumococcal vaccination in Uruguay

Introduction: Streptococcus pneumoniae infections are not frequent in neonates, but presents high morbidity and mortality. In 2008, the 7-valent pneumococcal conjugate vaccine (PCV) was introduced in the childhood vaccination schedule and then replaced by 13-valent PCV in 2010. First dose is given at 2 months of age. Protection of neonates is expected with universal vaccination. Objective: To describe the clinical presentation, microbiology and outcome of neonates with pneumococcal invasive infections (PII) detected in two hospitals in Uruguay in 2001-2007 (pre-vaccination), 2008 (intervention) and 2009-2013 (post-vaccination). Methods: A descriptive, retrospective study was done at Pereira Rossell Hospital and Paysandú Hospital. All isolates of S. pneumoniae obtained from normally sterile fluids were included. Data were obtained from the clinical records and the microbiology laboratory. A statistical analysis with absolute frequencies, relative, rates and relative risk was performed. Results: 25 neonates were enrolled with diagnosis of: sepsis (n = 13), meningitis (n = 9), bacteremia (n = 1), pneumonia with empyema (n = 1) and pneumonia (n = 1). The incidence of PII in the prevaccination period was 19/25, with a rate of 0.30/1,000 births, compared to post-vaccination rate of 0.04/1,000. The relative risk was 5.9. 6/20 (30%) cases of death were reported (meningitis n = 3; sepsis n = 2; empyema n = 1). Most common serotypes were 5 and 1 (14/25) and 24/25 strains were susceptible to penicillin. Discussion: The symptoms were indistinguishable to infections caused by other pathogens. PII cases decreased and no deaths occurred in the post-vaccination period. No increase in non-vaccine serotypes was observed.

Introducción: Streptococcus pneumoniae infrecuentemente produce infecciones en recién nacidos (RN), presentando elevada morbi-mortalidad. En Uruguay, en 2008 se incorporó al calendario de inmunizaciones infantil la vacuna conjugada neumocóccica (VCN) 7 valente, (sustituída por VCN13 en 2010). La vacunación comienza a los dos meses de vida. Se espera que la vacunación universal tenga impacto en la protección de RN. Objetivo: Describir la presentación clínica, microbiología y evolución de RN con enfermedad neumocóccica invasora (ENI), identificados en dos hospitales de Uruguay, años 2001-2007 (pre-vacunación), 2008 (intervención) y 2009-2013 (post-vacunación). Material y Métodos: Estudio descriptivo, retrospectivo. Lugar: Hospital Pereira Rossell y Hospital Paysandú. Se incluyeron todos los aislados de S. pneumoniae a partir de líquidos normalmente estériles. Fuente de datos: laboratorios de bacteriología e historias clínicas. Análisis estadístico: frecuencias absolutas, relativas, tasas y riesgo relativo. Resultados: RN con ENI: 25, sepsis (n: 13), meningitis (n: 9), bacteriemia (n: 1), neumonía con empiema (n: 1), neumonía (n: 1). Incidencia de ENI en el período pre-vacunación 19/25, tasa 0,30/1.000 nacimientos; tasa post-vacunación: 0,04/1.000. Riesgo relativo 5,9. Fallecimientos: 6/20 (30%): meningitis (n: 3), sepsis (n: 2), empiema (n: 1). Los serotipos más frecuentes fueron: 5 y 1 (14/25). Susceptibles a penicilina: 24/25. Discusión: Los síntomas fueron indistinguibles de infecciones causadas por otros patógenos. Disminuyeron los casos de ENI y no ocurrieron fallecimientos en el período post-vacunación. No aumentaron los serotipos no vacunales.

Prevalencia de Streptococcus pneumoniae serotipo 19A antes y después de la introducción de la vacuna conjugada heptavalente en México / Prevalence of Streptococcus pneumoniae serotype 19A before and after the introduction of the heptavalent conjugate vaccine in Mexico

Objetivo. Conocer la prevalencia de S. pneumoniae serotipo 19A (Spn19A) antes y después de la introducción de la vacuna conjugada heptavalente (PCV7) en México. Material y métodos. Estudio descriptivo realizado con la información sobre vigilancia de enfermedades causadas por neumococos, generada por la red Sireva. Se realizó un análisis de regresión lineal con la proporción de cepas de Spn19A por año, en dos periodos. Los datos se analizaron con el paquete estadístico SPSS v.18. Resultados. Durante el periodo 2000-2012 se recuperaron 1 825 cepas de S. pneumoniae causantes de infección en población pediátrica, de las cuales 225/12.3% fueron Spn19A, y de éstos, 75/6.3% se aislaron en el periodo 2000-2008 y 150/23.6% en el periodo 2009-2012. La resistencia antimicrobiana post-vacunal aumentó para todos los fármacos, excepto a vancomicina. Conclusión. Se observó que la frecuencia de este serotipo y la resistencia a antimicrobianos aumentó posterior a la introducción de la PCV7.

Objective. To determine the prevalence of S. pneumoniae serotype 19A (Spn19A), before and after the introduction of heptavalent pneumococcal conjugate vaccine (PCV7) in Mexico. Materials and methods. Descriptive study carried out in Mexico with surveillance information of pneumococcal disease, generated from the Sireva network. We performed lineal regression analysis with the proportion of Spn19A by year in two study periods. Data were analyzed using SPSS v.18 software. Results. A total of 1825 S. pneumoniae strains causing infection in pediatric population were recovered in the period 2000-2012, 225/12.3% were Spn19A, and of these, 75/6.3% were isolated in 2000-2008 and 150/23.6% in 2009-2012. There was an increase in antimicrobial resistance post-vaccination for all drugs except vancomycin. Conclusion. It was observed that the frequency of this serotype and antimicrobial resistance increased after the introduction of PCV7.

Calendario de inmunizaciones 2024 / immunisation schedule 2024

Calendario de Inmunizaciones 2024 de población infantil, escolar y adulta.

Calendario de inmunizaciones infantil 2024 / childhood immunisation schedule 2024

Calendario de inmunización para población infantil.