Pediatric Parapneumonic Empyema, Spain

Abstract

Pediatric parapneumonic empyema (PPE) has been increasing in several countries including Spain. Streptococcus pneumoniae is a major PPE pathogen; however, antimicrobial pretreatment before pleural fl uid (PF) sampling frequently results in negative diagnostic cultures, thus greatly underestimating the contribution of pneumococci, especially pneumococci susceptible to antimicrobial agents, to PPE. The study aim was to identify the serotypes and genotypes that cause PPE by using molecular diagnostics and relate these data to disease incidence and severity. A total of 208 children with PPE were prospectively enrolled; blood and PF samples were collected. Pneumococci were detected in 79% of culture-positive and 84% of culture-negative samples. All pneumococci were genotyped by multilocus sequence typing. Serotypes were determined for 111 PPE cases; 48% were serotype 1, of 3 major genotypes previously circulating in Spain. Variance in patient complication rates was statistically signifi cant by serotype. The recent PPE increase is principally due to nonvaccine serotypes, especially the highly invasive serotype 1. P leural effusions occur in at least 40% of children hospitalized with bacterial pneumonia. Occasionally, the infectious agent invades the pleura to cause pediatric paraneumonic empyema (PPE) (1), characterized by the presence of pus. Although rarely associated with fatalities in industrialized countries, PPE often results in prolonged hospitalization and surgical intervention, and patients are at risk for serious and long-lasting illness (2,3).An increasing incidence of PPE has been reported in several countries since the mid-1990s (2-6), but it is not clear why. Streptococcus pneumoniae is the most frequently found microorganism in most recent reports. However, conventional microbiologic culture methods have low sensitivity, usually because of antimicrobial pretreatment before sterile-site sampling. Consequently, the contribution of antimicrobial drug-susceptible serotypes might be higher than reported estimates. Molecular and antigen detection-based techniques, including direct molecular typing of culture-negative pleural fl uid (PF) samples (7), can be useful adjuncts in defi ning the contributory role of different microorganisms and pneumococcal serotypes to PPE etiology (4,8).Our study's goal was to prospectively investigate the molecular epidemiology of pneumococcal PPE among children admitted to 3 of the largest tertiary-care pediatric hospitals in Spain. There were 4 objectives: 1) identify the serotypes and multilocus sequence typing (MLST) genotypes causing PPE and determine whether a temporal change in the circulating genotypes could explain the recent increase; 2) determine whether the causal genotypes were only associated with PPE or also caused other invasive pneumococcal disease (IPD) in the same population, or were carried by healthy children; 3) compare serotypes and genotypes recovered from northern and southern Spain in the context of regional differences in 7-valent pneumococcal conjugat...

Estado de portador de neumococo en niños y su relación con la enfermedad invasiva: ¿Qué ha cambiado tras la introducción de la vacuna conjugada?

“…En nuestro país, los serotipos que actualmente producen la mayoría de las ENI en niños son 19A, 1, 6A, 7F, 5, 3, 24F y serogrupo 15, y de los vacunales aún persiste con mantenida incidencia el 14 11,22,59,[62][63][64][65][70][71][72][73] , mientras que los que previamente las producían, por orden de frecuencia y en menores de dos años según datos del Laboratorio Nacional de Referencia de Neumococos 22 , eran 14, 19F, 6B, 23F, 6A, 19A, 18C y 9V, y en niños de dos a cinco años eran 14, 18C, 1, 6B, 19F, 23F, 6A y 9V. Además, se mantienen algunas peculiaridades locales, como el caso de un brote de ENI por serotipo 5 en Madrd 70,73 , que afectó sobre todo a niños de uno a cuatro años en forma de neumonía bacteriémica, y de bacteriemia.…”

“…Es preciso comentar uno de los hechos más destacados coincidentes o consecuentes a la introducción de la VCN-7, y que ha sido el importante aumento de los ingresos hospitalarios por neumonías con empiema en niños (por ejemplo, un número 13 veces superior de los ingresos por este motivo en los hospitales de Sevilla y Málaga entre 1998 y 2006, o un incremento de seis veces en los hospitales de Barcelona de 2004 a 2006) 72 . En el 48% de este grupo de niños con neumonía complicada se demostró (mediante proteína C reactiva [PCR], pruebas gené-ticas y/o cultivo) el serotipo 1 como causante.…”

Vacuna conjugada contra el neumococo: ¿Es una prevención universal adecuada de la enfermedad neumocócica?

“…Diversos estudios han puesto de manifiesto que el aumento de los serotipos 1, 3 y 19A, no incluidos en la vacuna, serían responsables de dicho aumento [21][22] . El serotipo 1 es el más involucrado en el desarrollo de los derrames pleurales suponiendo en un estudio el 48% de los casos 23 . Según los datos de la región norteamericana de Intermountain West, el número de casos de empiema pleural pasó de 38 casos/año a 71,5 casos/año [21][22][23][24] .…”

“…El serotipo 1 es el más involucrado en el desarrollo de los derrames pleurales suponiendo en un estudio el 48% de los casos 23 . Según los datos de la región norteamericana de Intermountain West, el número de casos de empiema pleural pasó de 38 casos/año a 71,5 casos/año [21][22][23][24] . En un estudio realizado en España 25 los autores atribuyen el aumento de derrames al aumento global del número de neumonías bacterianas, manteniéndose constante la proporción de complicaciones (aunque repasando los datos del estudio donde se afirma esto, el número de neumonías aumenta ligeramente, de 36 a 41, mientras que el porcentaje de derrames pasa de 16% a 24% como puede verse en la tabla 1).…”

Current Trends in Streptococcus pneumoniae Infections and Their Treatment

“…Non-PCV7 serotype 1 has been linked to pediatric empyema cases [77,78]. Genotypic analysis using multi-locus sequence typing of pneumococcal serotype 1 isolates have shown that ST 306, a newly detected genotype, emerged after PCV7 implementation whereas STs-227, -228, and -304 were previously existing genotypes [78,79] . The pathogenesis involves hematogenous spread of microorganisms, and the most commonly involved bones include the femur and humerus [80].…”