Serotypes and Clonal Composition of Streptococcus pneumoniae Isolates Causing IPD in Children and Adults in Catalonia before 2013 to 2015 and after 2017 to 2019 Systematic Introduction of PCV13

The goal of this study was to investigate the distribution of serotypes and clonal composition of Streptococcus pneumoniae isolates causing invasive pneumococcal disease (IPD) in Catalonia, before and after systematic introduction of PCV13. Pneumococcal strains isolated from normally sterile sites obtained from patients of all ages with IPD received between 2013 and 2019 from 25 health centers of Catalonia were included. Two study periods were defined: presystematic vaccination period (2013 and 2015) and systematic vaccination period (SVP) (2017 to 2019). A total of 2,303 isolates were analyzed. In the SVP, there was a significant decrease in the incidence of IPD cases in children 5 to 17 years old (relative risk [RR] 0.61; 95% confidence interval [CI] 0.38 to 0.99), while there was a significant increase in the incidence of IPD cases in 18- to 64-year-old adults (RR 1.33; 95% CI 1.16 to 1.52) and adults over 65 years old (RR 1.23; 95% CI 1.09 to 1.38). Serotype 8 was the major emerging serotype in all age groups except in 5- to 17-year-old children. In children younger than 5 years old, the main serotypes in SVP were 24F, 15A, and 3, while in adults older than 65 years they were serotypes 3, 8, and 12F. A significant decrease in the proportions of clonal complexes CC156, CC191, and ST306 and an increase in those of CC180, CC53, and CC404 were observed. A steady decrease in the incidence of IPD caused by PCV13 serotypes indicates the importance and impact of systematic vaccination. The increase of non-PCV13 serotypes highlights the need to expand serotype coverage in future vaccines and rethink vaccination programs for older adults. IMPORTANCE We found that with the incorporation of the PCV13 vaccine, the numbers of IPD cases caused by serotypes included in this vaccine decreased in all of the age groups. Still, there was an unforeseen increase of the serotypes not included in this vaccine causing IPD, especially in the >65-year-old group. Moreover, a significant increase of serotype 3 included in the vaccine has been observed; this event has been reported by other researchers. These facts call for the incorporation of more serotypes in future vaccines and a more thorough surveillance of the dynamics of this microorganism

Low transmission of SARS-CoV-2 derived from children in family clusters: An observational study of family households in the Barcelona Metropolitan Area, Spain

Background: Family clusters offer a good opportunity to study viral transmission in a stable setting. We aimed to analyze the specific role of children in transmission of SARS-CoV-2 within households. Methods: A prospective, longitudinal, observational study, including children with documented acute SARS-CoV-2 infection attending 22 summer-schools in Barcelona, Spain, was performed. Moreover, other patients and families coming from other school-like environments that voluntarily accessed the study were also studied. A longitudinal follow-up (5 weeks) of the family clusters was conducted to determine whether the children considered to be primary cases were able to transmit the virus to other family members. The household reproduction number (Re*) and the secondary attack rate (SAR) were calculated. Results: 1905 children from the summer schools were screened for SARS-CoV-2 infection and 22 (1.15%) tested positive. Moreover, 32 additional children accessed the study voluntarily. Of these, 37 children and their 26 households were studied completely. In half of the cases (13/26), the primary case was considered to be a child and secondary transmission to other members of the household was observed in 3/13, with a SAR of 14.2% and a Re* of 0.46. Conversely, the SAR of adult primary cases was 72.2% including the kids that gave rise to the contact tracing study, and 61.5% without them, and the estimated Re* was 2.6. In 4/13 of the paediatric primary cases (30.0%), nasopharyngeal PCR was persistently positive > 1 week after diagnosis, and 3/4 of these children infected another family member (p<0.01). Conclusions: Children may not be the main drivers of the infection in household transmission clusters in the study population. A prolonged positive PCR could be associated with higher transmissibility

Características clínicas y microbiológicas de la enfermedad neumocócica invasiva pediátrica en Barcelona en la era de la vacuna heptavalente conjugada

[spa] La enfermedad neumocócica invasiva (ENI) constituye un problema grave de Salud Pública en la edad infantil, con una morbimortalidad considerable. En los últimos años se han introducido vacunas adecuadas para la edad infantil (año 2001:vacuna heptavalente conjugada, PCV7, año 2010:vacunas decavalente y trecevalente conjugadas). Desde la comercialización de la PCV7 se ha observado una emergencia de la ENI por serotipos no incluidos en la PCV7 (SNV) en nuestro medio. Esta tesis pretende a partir del análisis de la ENI que ha tenido lugar en los últimos años en nuestro medio (cuando la PCV7 era la única vigente) en una área sin vacunación sistemática, identificar los factores clínicos y microbiológicos asociados a la emergencia de ENI por SNV. Los objetivos de la tesis son: determinar la incidencia de ENI en menores de 5 años en nuestro medio, sus principales características clínicas y microbiológicas y las características clínicas y moleculares de la ENI producida por el serotipo 19A. Los 2 artículos publicados que componen la tesis y que permiten contestar estos objetivos son: 1/Clinical presentation of invasive pneumococcal disease in Spain in the era of heptavalent conjugate vaccine (Pediatr Infect Dis J. 2012; 31(2):124-8) y 2/ Emergence of invasive pneumococcal disease caused by multidrug-resistant serotype 19A among children in Barcelona (J Infect.2009; 59(2):75-82). El primer artículo expone un estudio prospectivo en el que se incluyen los niños < 5 años con ENI diagnosticados en los hospitales Sant Joan de Déu y Vall d’Hebron. La recogida se hizo durante 3 años consecutivos (2007-2009). Se incluyen pacientes diagnosticados por cultivo y/o PCR. Los principales resultados fueron:se incluyeron 319 pacientes, con una media de edad de 29.6 meses. Comparando las incidencias del 2007 y 2009 (76.2 y 109.9 casos/100000 habitantes,respectivamente) se observa un incremento del 44%. La principal manifestación clínica fueron las neumonías (79.6%), seguido de las meningitis (9.1%) y bacteriemias (7.8%). El diagnóstico se hizo por cultivo en 38.6% pacientes y en 61.4% por PCR en tiempo real. Pudo hacerse el serotipado en 300 casos, 91% eran SNV. El serotipo más frecuente fue el 1 (20.7%), seguido del 19A (15.7%) y el 3(12.3%). Una concentración mínima inhibitoria a la penicilina ≥ 0.12 g/ml se detectó en 34.4%. El secuenciotipo 306 expresando el serotipo 1 fue el más frecuente (20.3%). El segundo artículo se centra en la caracterización del 19A. Este serotipo se asocia a multirresistencia a antibióticos por lo que su estudio es relevante. Se trata de un estudio prospectivo realizado entre 1997 y 2007 en el que se incluyen los niños < 18 años con ENI por 19A del Hospital Sant Joan de Déu. Los principales resultados fueron:comparando la época prevacunal (1997-2001) con la vacunal inicial (2002-2004) y la vacunal tardía (2005-2007) se observa un incremento de ENI causada por 19A: 1.7% vs 14.8% vs 21.9% respectivamente (p:0.002). Todos los 19A aislados en la época prevacunal fueron sensibles a la penicilina, mientras que en la vacunal tardía, 44% eran resistentes (p:0.01). Se detectaron 15 secuenciotipos diferentes expresando el 19A, 10 de los cuales eran secuenciotipos preexistentes asociados al 19A, incluyendo los multirresistentes ST320 y ST276. Las principales conclusiones de la tesis son: -La ENI continúa aumentando en Barcelona, la incidencia es mayor que la descrita previamente debido a la baja sensibilidad del cultivo. -Los SNV fueron los responsables del 91% de los casos de ENI y la neumonía fue el principal diagnóstico. -El 19A se está extendiendo rápidamente y se está convirtiendo en una causa importante de ENI en la era vacunal. -El aumento del 19A se relaciona con la emergencia de clones sensibles y resistentes, varios de ellos relacionados con clones multirresistentes conocidos.[eng] Clinical and microbiological characteristics of pediatric invasive pneumococcal disease in Barcelona in the era of heptavalent conjugate vaccine The aim of this doctoral thesis is to analyze the rate of incidence, clinical presentation, serotype, and clonal distribution of invasive pneumococcal disease (IPD) in the era of heptavalent pneumococcal conjugate vaccine (PCV7) in Barcelona and to describe the epidemiology of IPD caused by Streptococcus pneumoniae serotype 19A. The 2 published articles that compose the thesis are: 1/Clinical presentation of invasive pneumococcal disease in Spain in the era of heptavalent conjugate vaccine (Pediatr Infect Dis J. 2012; 31(2):124-8) and 2/ Emergence of invasive pneumococcal disease caused by multidrug-resistant serotype 19A among children in Barcelona (J Infect.2009; 59(2):75-82). The first paper describes a prospective study comprising all children <5 years with IPD who were managed in 2 tertiary-care pediatric hospitals during 3 years (2007-2009). The diagnosis was made by positive culture and/or by real-time PCR. In this study, 319 patients were included. Comparing rates in 2007 and 2009 an increase of 44% was observed. The main clinical presentation was pneumonia (79.6%). Serotype study was performed in 300 episodes and 91% were non-PCV7 serotypes. The most frequent serotypes were 1 (20.7%), 19A (15.7%) and 3 (12.3%). Sequence type 306 expressing serotype 1 was the most frequent clonal type detected (20.3%). The second paper describes the clinical and molecular epidemiology of serotype 19A. This is a prospective study that includes all children <18 years with IPD caused by 19A who were admitted to a Children’s Hospital in Barcelona (1997-2007).Serotyping, antibiotic susceptibility and clonal analysis were performed. Comparing the pre-vaccine period (1997-2001) with the early vaccine period (2002-2004) and the late vaccine period (2005-2007) there was an increase of IPD caused by 19A. All 19A isolated in the pre-vaccine and early vaccine periods were penicillin susceptible, while in the late vaccine period, 44% were penicillin nonsusceptible (p:0.01).A clonal analysis revealed 15 different sequence types expressing serotype 19A.10 of them were pre-existing STs associated with 19A including the multidrug-resistant ST 320 and ST276. The main conclusions of the thesis are: -IPD continues to increase in Barcelona. -Non-PCV7 serotypes were responsible for 91% of episodes and pneumonia was the main clinical presentation. -There was an increase of IPD caused by 19A which was mainly related with the emergence of pre-existing clones several of them closely related with

Recurrent invasive pneumococcal disease in children: Underlying clinical conditions, and immunological and microbiological characteristics.

Purpose Clinical, immunological and microbiological characteristics of recurrent invasive pneumo-coccal disease (IPD) in children were evaluated, differentiating relapse from reinfection, in order to identify specific risk factors for both conditions. Methods All patients<18 years-old with recurrent IPD admitted to a tertiary-care pediatric center from January 2004 to December 2011 were evaluated. An episode of IPD was defined as the presence of clinical findings of infection together with isolation and/or pneumococcal DNA detection by Real-Time PCR in any sterile body fluid. Recurrent IPD was defined as 2 or more episodes in the same individual at least 1 month apart. Among recurrent IPD, we differentiated relapse (same pneumococcal isolate) from reinfection. Results 593 patients were diagnosed with IPD and 10 patients died. Among survivors, 23 episodes of recurrent IPD were identified in 10 patients (1.7%). Meningitis was the most frequent form of recurrent IPD (10 episodes/4 children) followed by recurrent empyema (8 episodes/4 children). Three patients with recurrent empyema caused by the same pneumococcal clone ST306 were considered relapses and showed high bacterial load in their first episode. In contrast, all other episodes of recurrent IPD were considered reinfections. Overall, the rate of relapse of IPD was 0.5% and the rate of reinfection 1.2%. Five out of 7 patients with rein- fection had an underlying risk factor: cerebrospinal fluid leak (n = 3), chemotherapy treatment (n = 1) and a homozygous mutation in MyD88 gene (n = 1). No predisposing risk factors were found in the remainder. Conclusions recurrent IPD in children is a rare condition associated with an identifiable risk factor in case of reinfection in almost 80% of cases. In contrast, recurrent IPD with pleuropneumonia is usually a relapse of infection

Características de los pacientes con enfermedad neumocócica invasora que requieren ingreso en la unidad de cuidados intensivos

Introducción: La enfermedad neumocócica invasora (ENI) puede requerir ingreso en la unidad decuidados intensivos pediátricos (UCIP). El objetivo de este trabajo es analizar las característicasepidemiológicas, clínicas y microbiológicas asociadas a la ENI que predisponen el ingreso en laUCIP.Material y métodos: Estudio prospectivo de casos diagnosticados con ENI en tres hospitalespediátricos de Barcelona entre enero de 2012 y junio de 2016. Se analizaron las asociacionesentre el ingreso en la UCIP y las variables epidemiológicas, clínicas y microbiológicas.Resultados: Se incluyeron 263 casos con ENI. El 19% (n = 50) requirió ingreso en la UCIP. El 100%(7) de los pacientes con shock séptico, 84,2% (16) con meningitis y 15,2% (23) con neumoníacomplicada ingresaron en la UCIP. Las complicaciones más frecuentes fueron pulmonares (35,2%)y neurológicas (39,5%). La razón entre ingreso y no ingreso en la UCIP fue 4,17 veces mayor enlos sujetos con enfermedad de base. Los serotipos asociados al ingreso en la UCIP fueron el 19A(23% del total de este serotipo), el 14 (20%), el 3 (17%) y el serotipo 1 (12,5%). Conclusiones: La ENI requiere ingreso en la UCIP en caso de shock séptico y meningitis, noasí, de entrada, la neumonía complicada. El porcentaje de ingresos es mayor en los ni ̃nos conenfermedad de base. El ingreso en la UCIP conlleva una estancia más prolongada, así comocomplicaciones durante la fase aguda y secuelas, sobre todo, neurológicas. Los serotipos de lospacientes que ingresaron en la UCIP fueron, predominantemente, serotipos vacunales