Impact of the pneumococcal conjugate vaccine on pneumococcal parapneumonic empyema

Parapneumonic empyema in children: a scoping review of the literature

Community-acquired pneumonia can lead to a serious complication called empyema, which refers to pus within the pleural space. While it poses a significant threat to morbidity, particularly in children, it is fortunately not associated with high mortality rates. However, determining the best course of management for children, including decisions regarding antibiotic selection, administration methods, and treatment duration, remains a topic of ongoing debate. This scoping review aims to map the existing literature on empyema in children, including types of studies, microbiology, therapies (both antimicrobial and surgical) and patient outcomes. We systematically searched PubMed and SCOPUS using the terms "pediatric" (encompassing children aged 0 to 18 years) and "pleural empyema" to identify all relevant studies published since 2000. This search adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA ScR) checklist.A total of 127 studies was included. Overall, 15 attempted to compare medical treatments (alone or in combination with pleural drainage or fibrinolysis) with more invasive surgical approaches, and six studies compared diverse surgical interventions. However, the diversity of study designs makes it difficult to derive firm conclusions on the optimal approach to pediatric empyema. The heterogeneity in inclusion criteria, pharmacological/surgical approaches and settings limit the ability to draw definitive conclusions. Overall, 78 out of 10,896 children (0.7%) included in the review died, with mortality being higher in Asia and Africa. Our scoping review highlights important gaps regarding several aspects of empyema in children, including specific serotypes of the most common bacteria involved in the etiology, the optimal pharmacological and surgical approach, and the potential benefits of newer antibiotics with optimal lung penetration. New trials, designed on a multi-country level a higher number of patients and more rigorous inclusion criteria and designs, should be urgently funded.

Therapy of parapneumonic empyema in children: a protocol for a scoping review of the literature

Background

Empyema (the presence of pus in the pleural space) is a severe complication of community-acquired pneumonia and significant cause of morbidity, but, fortunately, not mortality in children. Between 0.6 and 2% of pneumonias are complicated by empyema and the three main pathogens involved are Streptococcus pneumoniae, Staphylococcus aureus and group A Streptococcus 1,2,3,4. Optimal management in children, especially the choice of antibiotics, method of administration and duration of therapy, pleural dranage or surgery, are still a matter of debate and currently, lack of strong specific recommendations. This paper displays the study protocol for a scoping review that aims to summarize the available literature on the microbiological epidemiology, the medical and surgical treatment options, and the outcomes of pleural empyema in pediatric population.

Methods

Comprehensive research combining the terms pediatric (children aged 0 to 18 years) and pleural empyema will be performed on PubMed and SCOPUS to identify all eligible studies. At first, two reviewers will screen the abstract and then their full text to determine the articles that meet the inclusion criteria. This work will be carried out independently, everyone on a different Excel spreadsheet and each researcher will be blinded to the decision of the other researcher. When the process is completed, in case of discordance, any disagreement will be identified and resolved through discussion or with help of a third author.

Dissemination

The findings of this review will be published in a peer-reviewed journal.

The burden of antibiotic resistance of the main microorganisms causing infections in humans - review of the literature

One of the biggest threats to human well-being and public health is antibiotic resistance. If allowed to spread unchecked, it might become a major health risk and trigger another pandemic. This proves the need to develop antibiotic resistance-related global health solutions that take into consideration microdata from various global locations. Establishing positive social norms, guiding individual and group behavioral habits that support global human health, and ultimately raising public awareness of the need for such action could all have a positive impact. Antibiotic resistance is not just a growing clinical concern but also complicates therapy, making adherence to current guidelines for managing antibiotic resistance extremely difficult. Numerous genetic components have been connected to the development of resistance; some of these components have intricate paths of transfer between microorganisms. Beyond this, the subject of antibiotic resistance is becoming increasingly significant in medical microbiology as new mechanisms underpinning its development are identified. In addition to genetic factors, behaviors such as misdiagnosis, exposure to broad-spectrum antibiotics, and delayed diagnosis contribute to the development of resistance. However, advancements in bioinformatics and DNA sequencing technology have completely transformed the diagnostic sector, enabling real-time identification of the components and causes of antibiotic resistance. This information is crucial for developing effective control and prevention strategies to counter the threat.

Emerging pneumococcal serotypes in Iraq: scope for improved vaccine development

Pneumococcal disease is a global public health concern as it affects the young, aged and the immunocompromised. The development of pneumococcal vaccines and their incorporation in the immunization programs has helped to reduce the global burden of disease. However, serotype replacement and the emergence of non-vaccine serotypes as well as the persistence of a few vaccine serotypes underscores the need for development of new and effective vaccines against such pneumococcal serotypes. In the Middle East, places of religious mass gatherings are a hotspot for disease transmission in addition to the global risk factors. Therefore, the periodic surveillance of pneumococcal serotypes circulating in the region to determine the effectiveness of existing prevention strategies and develop improved vaccines is warranted. Currently, there is a lack of serotype prevalence data for Iraq due to inadequate surveillance in the region. Thus, this review aims to determine the pneumococcal serotypes circulating in Iraq which may help in the development and introduction of improved pneumococcal vaccines in the country.

A multicenter study on the epidemiology of complicated parapneumonic effusion in the era of currently available pneumococcal conjugate vaccines

BACKGROUND

Parapneumonic effusion (PPE) is a common complication of pneumonia. Streptococcus pneumoniae is the most common cause of bacterial pneumonia. A reduction in pneumonia hospitalizations has been observed since the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7). Despite this apparent benefit, an increase in the incidence of PPE was recorded in some countries following PCV7 implementation. As the 13-valent pneumococcal conjugate vaccine (PCV13) was expected to provide a wider protection against PPE, the aim of the present study was to evaluate the impact of PCV13 introduction on the epidemiology of complicated parapneumonic effusion (c-PPE) among children in the Athens greater area.

METHODS

All cases of community-acquired pneumonia (CAP) with PPE requiring chest tube insertion (complicated PPE, c-PPE) hospitalized in the 3 public Children's hospitals in Athens between 01/01/2004 and 31/12/2019 were included in the study.

RESULTS

A total of 426 cases of c-PPE associated with pneumonia were recorded of which 198 were admitted during 2004-2010 (period A, prePCV13/PCV -7 introduction period) and 228 during 2011-2018 (period B, post - PCV13 period). A definite bacterial etiology was established in 44.4 % of all cases and of those 25.4 % were caused by S. pneumoniae. An increasing trend in c-PPE incidence was observed during period A; although, a significant decrease on c-PPE annual rates was observed during the period B (p = 0.011), a remarkable increase in serotype 3 cases was recorded.

CONCLUSION

A decreasing time trend in c-PPE cases among children was shown after the introduction of PCV13 in our area. However, serotype 3 is nowadays a common cause of PPE. Hence, continuous surveillance is imperative in order to follow c-PPE epidemiology over time.

Epidemiological characteristics and serotype distribution of culture-confirmed pediatric pneumococcal pneumonia before and after PCV 10 introduction, a multicenter study in Bogota, Colombia, 2008-2019

BACKGROUND

Pneumococcal conjugate vaccines (PCVs) have decreased pneumonia in children. Colombia introduced mass vaccination with PCV10 in 2012.

METHODS

Cases of pneumococcal pneumonia from 10 hospitals were included. Two periods were compared: pre-PCV10: 2008-2011 and post-PCV10: 2014-2019. The objective was to compare epidemiological and clinical characteristics before and after PCV10 vaccination.

RESULTS

A total of 370 cases were included. Serotypes 1 (15, 11.2%) and 14 (33, 24.6%) were the most frequent in the pre-PCV10 period, with only 4 (3%) cases of serotype 19A and 1 case (0.7%) serotype 3. From the pre-PCV10 period to the post-PCV10 period, cases of serotypes 1 (6, 3.1%) and 14 (1, 7.8%) decreased, while cases of serotypes 19A (58, 30.2%), serotype 3 (32, 16.7%) and 6A (7, 3.6%) increased (p < 0.001); complicated pneumonia (CP) increased significantly (13.4% to 31.8%) (p < 0.001); hospitalizations increased from 8 (5.5-15) to 12 (7-22) days (p < 0.001); and the frequency of PICU admission increased from 32.8% to 51.6% (p = 0.001). The use of ampicillin-sulbactam (0.7% to 24%) and ceftriaxone/clindamycin (0.7% to 5.7%) increased in the post-PCV10 period. The duration of empirical antibiotic treatment was 7 (4-11) days in the pre-PCV10 period and increased to 10 (6-17) days (p < 0.001) in the post-PCV10 period. Lethality showed a slight nonsignificant increase (7.5% vs. 9.9%; p = 0.57) in the post-PCV10 period.

CONCLUSIONS

PCV10 significantly decreased cases of serotypes 1 and 14, with an increase in cases of serotypes 19A, 3 and 6A, which were the predominant serotypes and had greater severity (e.g., admission to the PICU, CP and more resistance, with an increase in the use of broad-spectrum antibiotics and longer hospitalization) and subsequently included in PCV13. Current data support national and regional evidence on the importance of replacing PCV10 with a higher valence that includes 19A, such as PCV13, with the aim of reducing circulation, particularly of this serotype.

Necrotizing pneumonia due to Streptococcus pneumoniae in children during the period of non-systematic use of PCV13 in Catalonia, Spain

BACKGROUND

Some studies have observed an increased incidence of necrotizing pneumonia (NP) in recent years. This might be related to the emergence of non-vaccine S. pneumoniae serotypes after PCV7 introduction although it is suggested that evolutionary factors may have modified the virulence and the interactions of pneumococci. The aim of this study was to clinically and microbiologically define NP in the population served by the three major paediatric hospitals in Barcelona (Catalonia, Spain).

METHODS

A prospective observational study was conducted in patients <18 years hospitalized due to invasive pneumococcal disease (January 2012-June 2016). Data of confirmed cases of pneumococcal NP (diagnosed by culture or DNA detection and serotyped) were collected. PCV13 was not systematically administered in Catalonia during the study period, but was available in the private market so the vaccination coverage in children increased from 48.2% to 74.5%.

RESULTS

35 cases of NP were identified. 77.1% of cases were associated with empyema. In the first 4 years, a trend to a decrease in NP incidence was observed (p=0.021), especially in children <5 years (p=0.006). Serotype 3 was responsible for 48.6% of NP cases. Five patients with NP due to serotype 3 were fully vaccinated for their age with PCV13.

CONCLUSIONS

Serotype 3 has a preeminent role in pneumococcal NP and was associated with all PCV13 vaccination failures. Although in our series the incidence does not seem to be increasing, evolution of pneumococcal NP rates should be monitored after inclusion of PCV13 in the systematic calendar.

Assessing the impact of the 13 valent pneumococcal vaccine on childhood empyema in Australia

BACKGROUND

Empyema is a serious complication of pneumonia frequently caused by Streptococcus pneumoniae (SP). We assessed the impact of the 13-valent pneumococcal conjugate vaccine (13vPCV) on childhood pneumonia and empyema after inclusion in the Australian National Immunisation Program.

METHODS

For bacterial pneumonia and empyema hospitalisations, we ascertained incidence rates (IRs) using the National Hospital Morbidity Database International Statistical Classification of Disease discharge codes and relevant population denominators, and calculated incidence rate ratios (IRR) comparing the 13vPCV period (June 2012-May 2017) with the 7vPCV period (June 2007-May 2011). Blood and pleural fluid (PF) cultures and PF PCR of 401 children with empyema from 11 Australian hospitals during the 13vPCV period were compared with our previous study in the 7vPCV period.

FINDINGS

Across 7vPCV and 13vPCV periods, IRs per million children (95% CIs) were 1605 (1588 to 1621) and 1272 (1259 to 1285) for bacterial pneumonia, and 14.23 (12.67 to 15.79) and 17.89 (16.37 to 19.42) for empyema hospitalisations. IRRs were 0.79 (0.78 to 0.80) for bacterial pneumonia and 1.25 (1.09 to 1.44) for empyema. Of 161 empyema cases with SP serotypes, 147 (91.3%) were vaccine types. ST3 accounted for 76.4% of identified serotypes in the 13vPCV period, more than double than the 7vPCV period (p<0.001); ST19A decreased from 36.4% to 12.4%. No cases of ST1 empyema were identified in the 13vPCV period versus 14.5% in the 7vPCV period.

INTERPRETATION

13vPCV resulted in a significant reduction in all-cause hospitalisations for bacterial pneumonia but empyema hospitalisations significantly increased, with emergence of pneumococcal ST3 as the dominant serotype in empyema.

TRIAL REGISTRATION NUMBER

Australian and New Zealand Clinical Trial Registry ACTRN 12614000354684.

Emergent Pneumonia in Children

In recent decades there have been multiple pathogens, viruses and bacteria, which have emerged as causal agents of pneumonia affecting adults, albeit less frequently, to children. For the purposes of this article we have classified emerging pathogens as follows: True emerging, to pathogens identified for the very first time affecting human population (SARS-CoV-1, SARS-CoV-2, MERS-CoV, avian influenza, and hantavirus); Re-emerging, to known pathogens which circulation was controlled once, but they have reappeared (measles, tuberculosis, antimicrobial resistant bacteria such as CA-MRSA, Mycoplasma pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and new serotypes of post-vaccine pneumococcal); and finally, those that we have called old known with new presentations, including common pathogens that, in particular condition, have changed their form of presentation (rhinovirus, and non-SARS coronavirus). We will review for each of them their epidemiology, forms of presentation, therapy, and prognosis in children compared to the adult with the aim of being able to recognize them to establish appropriate therapy, prognostics, and effective control measures.

Higher Cytokine and Opsonizing Antibody Production Induced by Bovine Serum Albumin (BSA)-Conjugated Tetrasaccharide Related to Streptococcus pneumoniae Type 3 Capsular Polysaccharide

A number of studies have demonstrated the limited efficacy of S. pneumoniae type 3 capsular polysaccharide (CP) in the 13-valent pneumococcal conjugate vaccine against serotype 3 invasive pneumococcal diseases and carriage. Synthetic oligosaccharides (OSs) may provide an alternative to CPs for development of novel conjugated pneumococcal vaccines and diagnostic test systems. A comparative immunological study of di-, tri-, and tetra-bovine serum albumin (BSA) conjugates was performed. All oligosaccharides conjugated with biotin and immobilized on streptavidin-coated plates stimulated production of IL-1α, IL-2, IL-4, IL-5, IL-10, IFNγ, IL-17A, and TNFα, but not IL-6 and GM-CSF in monocultured mice splenocytes. The tetrasaccharide-biotin conjugate stimulated the highest levels of IL-4, IL-5, IL-10, and IFNγ, which regulate expression of specific immunoglobulin isotypes. The tetra-BSA conjugate adjuvanted with aluminum hydroxide elicited high levels of IgM, IgG1, IgG2a, and IgG2b antibodies (Abs). Anti-CP-induced Abs could only be measured using the biotinylated tetrasaccharide. The tetrasaccharide ligand possessed the highest binding capacity for anti-OS and antibacterial IgG Abs in immune sera. Sera to the tetra-BSA conjugate promoted greater phagocytosis of bacteria by neutrophils and monocytes than the CRM197-CP-antisera. Sera of mice immunized with the tetra-BSA conjugate exhibited the highest titer of anti-CP IgG1 Abs compared with sera of mice inoculated with the same doses of di- and tri-BSA conjugates. Upon intraperitoneal challenge with lethal doses of S. pneumoniae type 3, the tri- and tetra-BSA conjugates protected mice more significantly than the di-BSA conjugate. Therefore, it may be concluded that the tetrasaccharide ligand is an optimal candidate for development of a semi-synthetic vaccine against S. pneumoniae type 3 and diagnostic test systems.

Necrotizing pneumonia due to Streptococcus pneumoniae in children during the period of non-systematic use of PCV13 in Catalonia, Spain

BACKGROUND

Some studies have observed an increased incidence of necrotizing pneumonia (NP) in recent years. This might be related to the emergence of non-vaccine S. pneumoniae serotypes after PCV7 introduction although it is suggested that evolutionary factors may have modified the virulence and the interactions of pneumococci. The aim of this study was to clinically and microbiologically define NP in the population served by the three major paediatric hospitals in Barcelona (Catalonia, Spain).

METHODS

A prospective observational study was conducted in patients <18 years hospitalized due to invasive pneumococcal disease (January 2012-June 2016). Data of confirmed cases of pneumococcal NP (diagnosed by culture or DNA detection and serotyped) were collected. PCV13 was not systematically administered in Catalonia during the study period, but was available in the private market so the vaccination coverage in children increased from 48.2% to 74.5%.

RESULTS

35 cases of NP were identified. 77.1% of cases were associated with empyema. In the first 4 years, a trend to a decrease in NP incidence was observed (p=0.021), especially in children <5 years (p=0.006). Serotype 3 was responsible for 48.6% of NP cases. Five patients with NP due to serotype 3 were fully vaccinated for their age with PCV13.

CONCLUSIONS

Serotype 3 has a preeminent role in pneumococcal NP and was associated with all PCV13 vaccination failures. Although in our series the incidence does not seem to be increasing, evolution of pneumococcal NP rates should be monitored after inclusion of PCV13 in the systematic calendar.

Identifying pneumococci in parapneumonic pleural effusion: Is there a role for culture-independent methods?

OBJECTIVE

To evaluate culture-independent procedures (immunochromatography and quantitative polymerase chain reaction [qPCR]) in the detection and susceptibility of Streptococcus pneumoniae directly from culture-negative pleural fluid (PF) in children.

METHOD

Detection of S. pneumoniae in PF of children with parapneumonic effusion and/or empyema by using two culture-independent methods: an immunochromatographic membrane test (IMT) which identifies the pneumococcal C antigen, and a real-time PCR test to detect pneumococcal genes lytA and pbp2b, a marker of susceptibility of β-lactam agents, in PF samples.

RESULTS

We tested 36 PF specimens and recorded the previous use of antimicrobials. In the final analysis, 34 samples were included. IMT and qPCR presented positive results in 23 (67.6%) and 24 (70.6%) of the samples, respectively, showing a moderate agreement (k = 0.518) between the two methods. From the 36 children included, 34 (94.4%) had antibiotic data available by the time when PFs were collected. Thirty-four (100%) children had been given treatment before PF sampling, with 33 (97%) receiving β-lactam antibiotics administered empirically. Of the 24 lytA real-time positive samples, 21 (87.5%) were also positive for pbp2b, a marker of β-lactam susceptibility.

CONCLUSION

The reduced sensitivity of culture for pneumococcal detection can be improved through the addition of IMT and qPCR analysis. The utility of qPCR combining detection of lytA and a marker of β-lactam susceptibility should be explored further.

Long-term Association of 13-Valent Pneumococcal Conjugate Vaccine Implementation With Rates of Community-Acquired Pneumonia in Children

IMPORTANCE

In several countries, 5 years after 13-valent pneumococcal conjugate vaccine (PCV13) implementation, serotype replacement has been reported for invasive pneumococcal disease, which raises concerns about the long-term outcome of PCV13 implementation. The long-term effect of vaccination on community-acquired pneumonia (CAP) remains unknown.

OBJECTIVE

To assess the long-term outcome of PCV13 implementation on CAP in children.

DESIGN, SETTING, AND PARTICIPANTS

This quasi-experimental, population-based, interrupted time-series analysis was based on a prospective multicenter study conducted from June 2009 to May 2017 in 8 French pediatric emergency departments. All patients 15 years and younger with chest radiography-confirmed CAP were included.

EXPOSURES

Community-acquired pneumonia.

MAIN OUTCOMES AND MEASURES

The number of CAP cases per 1000 pediatric emergency department visits over time, analyzed using a segmented regression model, adjusted for influenza-like illness syndromes.

RESULTS

We enrolled 12 587 children with CAP, including 673 cases of CAP with pleural effusion (5.3%), 4273 cases of CAP requiring hospitalization (33.9%), 2379 cases of CAP with high inflammatory biomarkers (18.9%), and 221 cases of proven pneumococcal CAP (1.8%). The implementation of PCV13 in 2010 was followed by a sharp decrease in the frequency of CAP (-0.8% per month [95% CI, -1.0% to -0.5% per month]), from 6.3 to 3.5 cases of CAP per 1000 pediatric emergency department visits until May 2014, then a slight increase since June 2014 (0.9% per month [95% CI, 0.4%-1.4% per month]), until 3.8 cases of CAP per 1000 pediatric emergency department visits in May 2017. There were marked immediate decreases in cases of CAP with pleural effusion (-48% [95% CI, -84% to -12%]), CAP requiring hospitalization (-30% [95% CI, -56% to -5%]), and CAP with high inflammatory biomarkers (-30% [95% CI, -54% to -6%]), without any rebound thereafter.

CONCLUSIONS AND RELEVANCE

The changes associated with PCV13 use 7 years after implementation remain substantial, especially for CAP with pleural effusion, CAP requiring hospitalization, and CAP with high inflammatory biomarkers. Emerging non-PCV13 serotypes may be less likely involved in severe CAP than invasive pneumococcal disease.

Trends in Hospital Treatment of Empyema in Children in the United States

OBJECTIVE

To evaluate trends in procedures used to treat children hospitalized in the US with empyema during a period that included the release of guidelines endorsing chest tube placement as an acceptable first-line alternative to video-assisted thoracoscopic surgery.

STUDY DESIGN

We used National Inpatient Samples to describe empyema-related discharges of children ages 0-17 years during 2008-2014. We evaluated trends using inverse variance weighted linear regression and characterized treatment failure using multivariable logistic regression to identify factors associated with having more than 1 procedure.

RESULTS

Empyema-related discharges declined from 3 in 100 000 children to 2 in 100 000 during 2008-2014 (P = .04, linear trend). There was no significant change in the proportion of discharges having 1 procedure (66.1% to 64.1%) or in the proportion having 2 or more procedures (22.1% to 21.6%). The proportion coded for video-assisted thoracoscopic surgery as the only procedure declined (41.4% to 36.2%; P = .03), and the proportions coded for 1 chest tube (14.6% to 20.9%; P = .04) and 2 chest tube procedures (0.9% to 3.5%; P < .01) both increased. The median length of stay for empyema-related discharges remained unchanged (9.3 days to 9.8 days; P = .053). Having more than 1 procedure was associated with continuous mechanical ventilation (adjusted OR, 2.7; 95% CI, 1.8-4.1) but not with age, sex, payer, chronic conditions, transfer admission, hospital size, or census region.

CONCLUSIONS

The use of video-assisted thoracoscopic surgery to treat children in the US hospitalized with empyema seems to be decreasing without associated increases in length of stay or need for additional drainage procedures.

Pneumococcal Vaccines: Host Interactions, Population Dynamics, and Design Principles

Streptococcus pneumoniae (the pneumococcus) is a nasopharyngeal commensal and respiratory pathogen. Most isolates express a capsule, the species-wide diversity of which has been immunologically classified into ∼100 serotypes. Capsule polysaccharides have been combined into multivalent vaccines widely used in adults, but the T cell independence of the antibody response means they are not protective in infants. Polysaccharide conjugate vaccines (PCVs) trigger a T cell–dependent response through attaching a carrier protein to capsular polysaccharides. The immune response stimulated by PCVs in infants inhibits carriage of vaccine serotypes (VTs), resulting in population-wide herd immunity. These were replaced in carriage by non-VTs. Nevertheless, PCVs drove reductions in infant pneumococcal disease, due to the lower mean invasiveness of the postvaccination bacterial population; age-varying serotype invasiveness resulted in a smaller reduction in adult disease. Alternative vaccines being tested in trials are designed to provide species-wide protection through stimulating innate and cellular immune responses, alongside antibodies to conserved antigens.

Streptococcus pneumoniae potently induces cell death in mesothelial cells

Pleural infection/empyema is common and its incidence continues to rise. Streptococcus pneumoniae is the commonest bacterial cause of empyema in children and among the commonest in adults. The mesothelium represents the first line of defense against invading microorganisms, but mesothelial cell responses to common empyema pathogens, including S. pneumoniae, have seldom been studied. We assessed mesothelial cell viability in vitro following exposure to common empyema pathogens. Clinical isolates of S. pneumoniae from 25 patients with invasive pneumococcal disease and three reference strains were tested. All potently induced death of cultured mesothelial cells (MeT-5A) in a dose- and time-dependent manner (>90% at 10⁷ CFU/mL after 24 hours). No significant mesothelial cell killing was observed when cells were co-cultured with Staphylococcus aureus, Streptococcus sanguinis and Streptococcus milleri group bacteria. S. pneumoniae induced mesothelial cell death via secretory product(s) as cytotoxicity could be: i) reproduced using conditioned media derived from S. pneumoniae and ii) in transwell studies when the bacteria and mesothelial cells were separated. No excess cell death was seen when heat-killed S. pneumoniae were used. Pneumolysin, a cytolytic S. pneumoniae toxin, induced cell death in a time- and dose-dependent manner. S. pneumoniae lacking the pneumolysin gene (D39 ΔPLY strain) failed to kill mesothelial cells compared to wild type (D39) controls, confirming the necessity of pneumolysin in D39-induced mesothelial cell death. However, pneumolysin gene mutation in other S. pneumoniae strains (TIGR4, ST3 and ST23F) only partly abolished their cytotoxic effects, suggesting different strains may induce cell death via different mechanisms.

PCV13 vaccination impact: A multicenter study of pneumonia in 10 pediatric hospitals in Argentina

Introduction

In 2012, PCV13 was introduced into the National Immunization Program in Argentina, 2+1 schedule for children <2 years. Coverage rates for 1st and 3rd doses were 69% and 41.0% in 2012, 98% and 86% in 2013; 99% and 89% in 2014, respectively. The aims of this study were to evaluate impact of PCV13 on Consolidated Pneumonia (CP) and Pneumococcal Pneumonia (PP) burden, and to describe epidemiological-clinical pattern of PP during the three-year period following vaccine introduction.

Methods

Hospital-based study at 10 pediatric surveillance units in Argentina. CP and PP discharge rates per 10,000 hospital discharges were compared between the pre-vaccination period 2007–2011 (preVp), the year of intervention (2012) and the post-vaccination period 2013–2014 (postVp).

Results

Significant reduction in CP and PP discharge rates was observed in patients <5 years [% reduction (95%CI)]: 10.2% (6.3; 14.0) in 2012 and 24.8% (21.3; 28.2) in postVp for CP discharge rate; 59.5% (48.0; 68.5) in 2012 and 68.8% (58.3; 76.6) in postVp for PP discharge rate. Significant changes were also observed in children ≥5 years, mainly in PP discharge rate. A total of 297 PP cases were studied; 59.3% male; 31.3% <2 years; 42.9% had received PCV13 in 2012 and 84.5% in posVp. Case fatality rate was 3.4%. PCV13 serotypes decreased from 83.0% (39/47) in 2012 to 64.2% (52/81) in postVp, p = 0.039.

Conclusions

After PCV13 introduction, significant reduction in CP and PP discharge rates was observed in hospitalized children <5 years. In patients ≥5 years, PP discharge rate also decreased significantly.

Whole Exome Sequencing Identifies New Host Genomic Susceptibility Factors in Empyema Caused by Streptococcus pneumoniae in Children: A Pilot Study

Pneumonia is the leading cause of death amongst infectious diseases. Streptococcus pneumoniae is responsible for about 25% of pneumonia cases worldwide, and it is a major cause of childhood mortality. We carried out a whole exome sequencing (WES) study in eight patients with complicated cases of pneumococcal pneumonia (empyema). An initial assessment of statistical association of WES variation with pneumonia was carried out using data from the 1000 Genomes Project (1000G) for the Iberian Peninsula (IBS) as reference controls. Pseudo-replication statistical analyses were carried out using different European control groups. Association tests pointed to single nucleotide polymorphism (SNP) rs201967957 (gene MEIS1; chromosome 2; p-value_IBS = 3.71 × 10^-13) and rs576099063 (gene TSPAN15; chromosome 10; p-value_IBS = 2.36 × 10^-8) as the best candidate variants associated to pneumococcal pneumonia. A burden gene test of pathogenicity signaled four genes, namely, OR9G9, MUC6, MUC3A and APOB, which carry significantly increased pathogenic variation when compared to controls. By analyzing various transcriptomic data repositories, we found strong supportive evidence for the role of MEIS1, TSPAN15 and APOBR (encoding the receptor of the APOB protein) in pneumonia in mouse and human models. Furthermore, the association of the olfactory receptor gene OR9G9 has recently been related to some viral infectious diseases, while the role of mucin genes (MUC6 and MUC3A), encoding mucin glycoproteins, are well-known factors related to chronic obstructive airway disease. WES emerges as a promising technique to disentangle the genetic basis of host genome susceptibility to infectious respiratory diseases.

Pneumococcal Vaccination and Pneumonia Associated With Pleural Effusion in a Pediatric Population

OBJECTIVE

The aim was to assess the effect of the nonsystematic pneumococcal conjugate vaccine (PCV) on incidence of pneumonia associated with parapneumonic pleural effusion (PPE) in vaccinated and unvaccinated children.

METHODS

Cases were patients <15 years of age who had been diagnosed with pneumonia associated with PPE in a tertiary hospital in Navarra (Spain) between 1995 and 2014. The population <15 years of age and covered by the public health service was used as reference. The vaccination status of the cases and population was obtained from computerized medical records. Logistic regression analyses included vaccination status, age group and time periods: prevaccine (1995-2001) and vaccination with PCV7 (2002-2010) and PCV13 (2011-2014).

RESULTS

A total of 321 cases of PPE were included. The risk of PPE increased between the prevaccine and PCV7 period (adjusted odds ratio [OR], 3.34; 95% confidence interval [CI]: 2.37-4.71), while vaccination with PCV7 was found to be an independent risk factor (OR, 1.44; 95% CI: 1.09-1.89) in the same analysis. In the PCV13 period, the risk of PPE returned to the prevaccination incidence level among children vaccinated with PCV13 (OR, 1.07; 95% CI: 0.56-2.04), while unvaccinated children (OR, 1.69; 95% CI: 0.96-2.98) and overall those vaccinated with PCV7 (OR, 3.64; 95% CI: 2.15-6.17) maintained an increased risk of PPE.

CONCLUSION

The nonsystematic introduction of PCV7 was followed by an increased incidence of PPE. The subsequent introduction of PCV13 was associated with a return to the incidence level in the prevaccine period, mainly in children vaccinated with PCV13.

Trends in Pediatric Complicated Pneumonia in an Ontario Local Health Integration Network

Following the introduction of 7-valent pneumococcal vaccine (PCV7), while overall rates of invasive pneumococcal disease and pneumococcal pneumonia in children declined, rates of empyema increased. We examined changes in the incidence of hospitalization for pediatric complicated pneumonia (PCOMP) in Eastern Ontario, Canada, particularly since the introduction of the 13-valent vaccine (PCV13). A retrospective chart review was carried out evaluating previously healthy children admitted with PCOMP, which included empyema, parapneumonic effusion, necrotizing pneumonia, and lung abscess between 2002 and 2015. Three-hundred seventy-one children were included. Subjects had a median age of four years, and 188/370 (50.8%) required a chest tube. Admission rates changed markedly during this time period. The number of admissions per year rose most sharply between 2009 and 2012, corresponding to the period following introduction of PCV7 and then the occurrence of pandemic influenza A (H1N1). In children who likely received PCV13, the incidence of PCOMP returned to approximately pre-PCV7 levels. In contrast, rates of PCOMP in older children (who would not have received PCV13) remained elevated during the post-PCV13 time period. While rates of PCOMP, particularly in older children, remain elevated following the introduction of PCV13, this might be expected to resolve with more widespread vaccine coverage with PCV13 and herd immunity.

Paediatric invasive pneumococcal disease on the island of Gran Canaria: 16-year prospective study (2001-2016)

OBJECTIVES

To calculate the incidence of invasive pneumococcal disease (IPD) in the paediatric population of Gran Canaria (Spain), its clinical and epidemiological characteristics, serotype distribution, antibiotic resistance, and variations in these variables before and after the introduction of the PCV13 vaccine.

METHODS

Prospective hospital-based study including all patients (190) aged 0-14 years admitted with confirmed IPD between January 2001-May 2010 (152 cases) and June 2010-December 2016 (38 cases). Patients were divided into 3 age groups (<2 years; 2-5 years; and >5 years). Clinical symptoms were mutually-exclusively classified as meningitis, bacteraemic pneumonia, pleural effusion (PE), empyema or bacteraemia without a focus.

RESULTS

Most cases occurred in boys (59.47%), during autumn-winter (65.79%), in children aged <2 years (55.79%) and with mean age increasing from the pre-PCV13 to the post-PCV13 period (2.5 vs 3.1 years). Incidence between periods reduced by 66.4% (p<0.001): from 13.1/100,000 to 4.4/100,000. PEs (3.9% vs 18.4%, p<0.005) and empyemas (1.5% vs 16.7%, p=NS) increased in the post-PCV13 period whereas all other symptoms decreased, although this was not statistically significant. Vaccine serotypes (77% vs 40.6%, p=0.000), particularly serotypes 19A (23.9% vs 12.5%) and 14 (14.2% vs 9.4%), as well as erythromycin resistance (57.2% vs 7.9%, p=0.000) decreased in the post-PCV13 period.

CONCLUSION

IPD incidence, vaccine serotypes and erythromycin resistance decreased in the post-PCV13 period whereas PEs increased.

Complicated community acquired pneumonia in childhood: Different types, clinical course, and outcome

The incidence of pediatric community acquired complicated pneumonia (PCACP) is increasing. Questions addressed: Are different types of PCACP one disease? How do different treatment protocols affect the outcome?

METHODS

Retrospective analysis of medical records of PCACP hospitalizations in the three major hospitals in Jerusalem in the years 2001-2010 for demographics, clinical presentation, management, and outcome.

RESULTS

Of the 144 children (51% aged 1-4 years), 91% of Jewish origin; 40% had para-pneumonic effusion (PPE), 40% empyema (EMP), and 20% necrotizing pneumonia (NP). Bacterial origin was identified in 42% (empyema 79%, P = 0.009), most common S. pneumoniae (32%), group A streptococcus (9%). Patients with EMP, compared to PPE and NP, were less likely to receive prior antibiotic treatment (35% vs. 57% and 59%, respectively, P = 0.04). Mean hospitalization was longer in patients with NP followed by EMP and PPE (16.4 ± 10.6, 15.2 ± 7.9, and 12.7 ± 4.7 days, respectively), use of fibrinolysis was not associated with the outcome. All children had recovered to discharge regardless of antibiotic therapy or fibrinolysis.

ANSWER

NP is a more severe disease with prolonged morbidity and hospitalization in spite of prior antibiotic treatment. All types had favorable outcome regardless of treatment-protocol. Complicated pneumonia has an ethnic predominance. Pediatr Pulmonol. 2017;52:247-254. © 2016 Wiley Periodicals, Inc.

Prevention of Community-Acquired Pneumonia with Available Pneumococcal Vaccines

Community-acquired pneumonia (CAP) places a considerable burden on society. A substantial number of pediatric and adult CAP cases are due to Streptococcus pneumoniae, but fortunately there are effective vaccines available that have a significant impact on CAP-related medical, social, and economic problems. The main aim of this paper is to evaluate the published evidence concerning the impact of pneumococcal vaccines on the prevention of CAP in children and adults. Available data indicate that pneumococcal conjugate vaccines (PCVs) are effective in children, reducing all-cause CAP cases and bacteremic and nonbacteremic CAP cases. Moreover, at least for PCV7 and PCV13, vaccination of children is effective in reducing the incidence of CAP among adults. Recently use of PCV13 in adults alone or in combination with the pneumococcal polysaccharide vaccine has been suggested and further studies can better define its effectiveness in this group of subjects. The only relevant problem for PCV13 is the risk of a second replacement phenomenon, which might significantly reduce its real efficacy in clinical practice. Protein-based pneumococcal vaccines might be a possible solution to this problem.

Pneumococcal Disease in the Era of Pneumococcal Conjugate Vaccine

Universal immunization of infants and toddlers with pneumococcal conjugate vaccines over the last 15 years has dramatically altered the landscape of pneumococcal disease. Decreases in invasive pneumococcal disease, all-cause pneumonia, empyema, mastoiditis, acute otitis media, and complicated otitis media have been reported from multiple countries in which universal immunization has been implemented. Children with comorbid conditions have higher rates of pneumococcal disease and increased case fatality rates compared with otherwise healthy children, and protection for the most vulnerable pediatric patients will require new strategies to address the underlying host susceptibility and the expanded spectrum of serotypes observed.

When should clinicians suspect group A streptococcus empyema in children? A multicentre case-control study in French tertiary care centres

BACKGROUND

The incidence of invasive group A streptococcus (GAS) infections is increasing worldwide, whereas there has been a dramatic decrease in pneumococcal invasive diseases. Few data describing GAS pleural empyema in children are available.

OBJECTIVE

To describe the clinical and microbiological features, management and outcome of GAS pleural empyema in children and compare them with those of pneumococcal empyema.

DESIGN, SETTING AND PATIENTS

Fifty children admitted for GAS pleural empyema between January 2006 and May 2013 to 8 hospitals participating in a national pneumonia survey were included in a descriptive study and matched by age and centre with 50 children with pneumococcal empyema.

RESULTS

The median age of the children with GAS pleural empyema was 2 (range 0.1-7.6) years. Eighteen children (36%) had at least one risk factor for invasive GAS infection (corticosteroid use and/or current varicella). On admission, 37 patients (74%) had signs of circulatory failure, and 31 (62%) had a rash. GAS was isolated from 49/50 pleural fluid samples and from one blood culture. The commonest GAS genotype was emm1 (n=17/22). Two children died (4%). Children with GAS empyema presented more frequently with a rash (p<0.01), signs of circulatory failure (p=0.01) and respiratory disorders (p=0.02) and with low leucocyte levels (p=0.04) than children with pneumococcal empyema. Intensive care unit admissions (p<0.01), drainage procedures (p=0.04) and short-term complications (p=0.01) were also more frequent in patients with GAS empyema.

CONCLUSIONS

Pleural empyema following varicella or presenting with rash, signs of circulatory failure and leucopenia may be due to GAS. These features should prompt the addition to treatment of an antitoxin drug, such as clindamycin.

Pleural effusion with negative culture: a challenge for pneumococcal diagnosis in children

BACKGROUND

Pneumococcal parapneumonic effusion seems to be increasing in children in the postvaccine era and is frequently associated with negative culture. Due to the low yield of culture, culture-independent tools are evaluated.

METHODS

Culture-negative pleural fluid specimens from 38 children with parapneumonic effusion were examined for pneumococcal lytA by quantitative polymerase chain reaction (qPCR) and soluble antigen (C-polysaccharide) using an immunochromatographic test (BinaxNow Streptococcus pneumoniae).

RESULTS

In 81% (30/37) and 63% (24/38) of the specimens, a positive result was obtained by qPCR and antigen detection, respectively. Most mismatches were observed in specimens with low quantities of pneumococcal DNA and a negative antigen test.

CONCLUSIONS

Our results suggest an imperfect relationship between the 2 described methods. The immunochromatographic assay is a simple diagnostic tool, which can be used when resources are limited, and even after antibiotic use, but negative results may require confirmation through a more sensitive test, such as qPCR.

Incidence, aetiology and outcome of pleural empyema and parapneumonic effusion from 1998 to 2012 in a population of New Zealand children

AIM

To document rising incidence rates of childhood empyema and parapneumonic effusion (PPE) in South Auckland, New Zealand between 1998 and 2012; to compare epidemiology, pathogens and outcomes of children with empyema and PPE; and to ascertain whether primary care antibiotic prescribing, delayed presentation, or bacterial epidemiology might account for the rising incident rates.

METHODS

Children aged 0 to14 years hospitalised with pleural empyema or PPE were retrospectively identified. Empyema was defined by ultrasound and pleural tap criteria. PPE was defined as the presence of pleural fluid on chest xray not fulfilling empyema criteria. Epidemiology, clinical features, microbiology and outcomes of empyema and PPE were compared and incidence rates analysed.

RESULTS

Of 184 cases identified, 104 met the criteria for empyema. Empyema incidence increased from 1 per 100 000 children aged 0 to 14 years in 1998 to 10 per 100 000 in 2012, with a peak incidence of 13 per 100 000 in 2009. Staphylococcus aureus was most frequently detected (n=38), followed by Streptococcus pneumoniae (n=31). Cases of S. aureus empyema increased 4 fold over the 15 years. Dominant S. pneumoniae serotypes were 1 and 14. Thirty-five percent of empyema and 53% of PPE cases received pre-hospital antibiotics. Children who received pre-hospital antibiotics were more than 40% less likely to require surgical intervention than those not pre-treated.

CONCLUSIONS

Childhood empyema incidence has increased markedly in South Auckland. Paediatric S. aureus empyema is becoming increasingly common in South Auckland. Pre-hospital antibiotic prescribing may mitigate the need for surgical intervention in our population.

Early Streptococcus pneumoniae serotype changes in Utah adults after the introduction of PCV13 in children

INTRODUCTION

Pneumococcal conjugate vaccines (PCV) have indirect effects due to decreased Streptococcus pneumoniae colonization in vaccine recipients. We sought to determine whether the introduction of PCV13 in children led to changes in the epidemiology and clinical manifestations of invasive pneumococcal disease (IPD) in adults.

METHODS

We described demographics, comorbidities, clinical manifestations, and serotypes of IPD in Utah adults before (November 2009-February 2010) and after (March 2010-March 2012) the introduction of PCV13 in children. We also compare serotypes causing IPD in Utah adults and children.

RESULTS

After the introduction of PCV13 in the childhood vaccine program, the proportion of IPD due to PCV13 exclusive serotypes decreased significantly in Utah adults (64-40%, p=0.009), primarily due to a decline in serotype 7F (36-15%, p=0.008). There were non-significant increases in IPD due to Pneumococcal polysaccharide 23 (PPV23) unique serotypes and non-vaccine serotypes, most notably serotype 22F. Changes in the proportions of vaccine and non-vaccine serotypes were similar in adults and children. Meningitis was more commonly due to non-vaccine serotypes relative to non-meningitis cases (47% vs. 18%, p=0.007). When stratified by sex, decreases in PCV13 serotype IPD were only noted in men (76-33%, p=0.001).

CONCLUSIONS

Serotype epidemiology of IPD in adults closely follows that of children in the PCV13 era. Continued surveillance is needed to confirm whether replacement serotypes will lead to increases in pneumococcal meningitis and whether there are sex differences in the indirect effects of PCV vaccination in children.

Comparative Effectiveness of Oral Versus Outpatient Parenteral Antibiotic Therapy for Empyema

BACKGROUND

Treatment of pediatric parapneumonic empyema (PPE) requires several weeks of antibiotic therapy that is typically completed in the outpatient setting. The route of outpatient therapy can be oral or intravenous (outpatient parenteral antibiotic therapy [OPAT]). No studies have compared outcomes between oral therapy and OPAT for PPE.

METHODS

We identified children <18 years hospitalized from 2005 to 2014 at Primary Children's Hospital with PPE and discharged with oral therapy or OPAT. The primary outcome was the percentage of children who experienced all-cause complications after discharge. Complications included those that were related to pneumonia (including treatment failure, defined as readmission with reaccumulation of pleural fluid or abscess requiring drainage) or antibiotic therapy (eg, allergy, line clot) resulting in either a hospital readmission or emergency department/urgent care visit. All-cause complications were compared between oral therapy and OPAT by using propensity score-weighted logistic regression.

RESULTS

A total of 391 children were hospitalized with PPE; 337 (86%) were discharged with OPAT; 35 (9%) children experienced an all-cause complication, including 5 with oral (9.3%) and 30 (8.9%) with OPAT. Pneumonia and treatment-related complications were comparable (P = .25 and .78, respectively). Two patients treated with OPAT (1%) experienced treatment failure. After adjustment using propensity score weighting, the frequency of complications was similar between groups (adjusted odds ratio 0.97, 95% confidence interval 0.23-4.65).

CONCLUSIONS

The frequency of complications was similar with oral therapy and OPAT for children with PPE. Oral antibiotics may be considered safe and effective for children with PPE who will be discharged to complete therapy in the outpatient setting.

Analysis of Outcome of Intraplueral Streptokinase in Pediatric Empyema Thoracis even in Advanced Stages: A Prospective Study

Background:

Empyema thoracis in children causes significant morbidity. Standard treatment of Empyema thoracis includes tube drainage and antibiotics. But the tube drainage often fails. Intrapleural Streptokinase has been used in empyema thoracis with good success rate.

Objectives:

We evaluated the efficacy of intra-pleural Streptokinase in management of empyema thoracis even in advanced stages.

Patients and Methods:

A total of 28 patients with empyema thoracis requiring intercostal tube drainage aged zero to twelve years were included in the study who were admitted in Pediatric intensive care unit. 15,000 units/kg of Streptokinase was instilled into the pleural cavity. Response was assessed by clinical outcome, after unclamping and subsequent chest radiography and serial chest ultrasounds.

Results:

Streptokinase enhanced drainage in all patients with complete resolution of empyema thoracis in 26 patients. Two patients were referred for surgery. Only 7.2% required surgery. Streptokinase was equally effective if started before or after seven days.

Conclusions:

Intrapleural Streptokinase is the preferred treatment for treating pediatric empyema thoracis even in advanced stages and can avoid surgery.

A Pneumococcal Protein Array as a Platform to Discover Serodiagnostic Antigens Against Infection

Pneumonia is one of the most common and severe diseases associated with Streptococcus pneumoniae infections in children and adults. Etiological diagnosis of pneumococcal pneumonia in children is generally challenging because of limitations of diagnostic tests and interference with nasopharyngeal colonizing strains. Serological assays have recently gained interest to overcome some problems found with current diagnostic tests in pediatric pneumococcal pneumonia. To provide insight into this field, we have developed a protein array to screen the antibody response to many antigens simultaneously. Proteins were selected by experimental identification from a collection of 24 highly prevalent pediatric clinical isolates in Spain, using a proteomics approach consisting of "shaving" the cell surface with proteases and further LC/MS/MS analysis. Ninety-five proteins were recombinantly produced and printed on an array. We probed it with a collection of sera from children with pneumococcal pneumonia. From the set of the most seroprevalent antigens, we obtained a clear discriminant response for a group of three proteins (PblB, PulA, and PrtA) in children under 4 years old. We validated the results by ELISA and an immunostrip assay showed the translation to easy-to-use, affordable tests. Thus, the protein array here developed presents a tool for broad use in serodiagnostics.

Timely thoracoscopic decortication promotes the recovery of paediatric parapneumonic empyema

INTRODUCTION

Parapneumonic empyema is one of the most commonly encountered yet difficult to manage paediatric thoracic conditions. Conservative treatment with chest tube drainage and fibrinolytic agents had been proposed but operative decortication remains the gold standard for refractory cases. Thoracoscopic decortication has been advocated in recent years due to its superiority in terms of post-operative pain, cosmesis and other long-term results. However, few studies investigated the effect of timing on peri-operative outcomes. This study aims to explore the benefits of early decortication.

METHODS

Retrospective study of all patients who underwent thoracoscopic decortication between 1999 and 2013 at a tertiary referral centre was performed. Data were extracted from respective medical records. Patients' demographics, peri-operative outcomes, length of hospitalization and post-operative complications were analysed.

RESULTS

A total of 28 patients were identified, 12 males and 16 females. Average age of patients was 4.5 years (range 12 months-14 years). Right-sided empyema was involved in 14 of the patients. Patients who underwent operation within 2 weeks from symptom onset (n = 16) showed significant shorter post-operative hospital stay (mean 9.5 vs 20.4 days, p = 0.003) and total hospitalization duration (mean 19.3 vs 38.8 days, p < 0.001). Correlation study demonstrated a strong relation between delay in operation and prolonged hospitalization (r = 0.63, p = 0.001). The peri-operative and post-operative outcomes were similar. No major post-operative complication was encountered except one patient who required a second decortication for residual empyema.

CONCLUSION

Thoracoscopic decortication is a safe and feasible procedure for parapneumonic empyema. Timely surgery is recommended as it promotes early recovery and shorter hospitalization.

[Community acquired pneumonia in children: Treatment of complicated cases and risk patients. Consensus statement by the Spanish Society of Paediatric Infectious Diseases (SEIP) and the Spanish Society of Paediatric Chest Diseases (SENP)]

The incidence of community-acquired pneumonia complications has increased during the last decade. According to the records from several countries, empyema and necrotizing pneumonia became more frequent during the last few years. The optimal therapeutic approach for such conditions is still controversial. Both pharmacological management (antimicrobials and fibrinolysis), and surgical management (pleural drainage and video-assisted thoracoscopic surgery), are the subject of continuous assessment. In this paper, the Spanish Society of Paediatric Infectious Diseases and the Spanish Society of Paediatric Chest Diseases have reviewed the available evidence. Consensus treatment guidelines are proposed for complications of community-acquired pneumonia in children, focusing on parapneumonic pleural effusion. Recommendations are also provided for the increasing population of patients with underlying diseases and immunosuppression.

Clinical outcome of parapneumonic empyema in children treated according to a standardized medical treatment

Treatment of parapneumonic empyema (PE) consists of intravenous antibiotics and, in case of large effusions and persisting fever, pleural chest drain (±intrapleural fibrinolytics) or video-assisted surgical intervention. We standardized the treatment for PE in our tertiary care center choosing a first-step nonsurgical approach. The aim was to evaluate the need for surgery and to collect data on disease course, outcome, and microbiology. For all children treated for PE between 2006 and 2013, data were prospectively collected concerning treatment, length of stay, duration of fever, complications, and causative agent. Of 132 children treated for PE, 20 % needed surgical intervention. Analyzed per year, the need for surgery decreased from almost 40 % in 2007 to 0 % in 2010 again increasing to 40 % although this did not reach statistical significance (p = 0.115). Median duration of "in-hospital fever" was 5 days (IQR, 3-8). The duration of fever correlated with pleural LDH (r = 0.324; p = 0.002) and pleural glucose (r = -0.248; p = 0.021) and was inversely correlated with pleural pH (r = -0.249; p = 0.046). Based on pleural PCR data, 85 % of PE were caused by Streptococcus pneumoniae (40 % serotype 1).

CONCLUSION

After introduction of a standardized primary medical approach (chest drain ± fibrinolysis) for PE in our institution, the need for surgical rescue interventions overall remained at 20 %, which is higher than in some other reports. Difference in microbiology or disease severity could not be proven.

Aetiology of paediatric pneumonia with effusion in the Dominican Republic and the potential impact of pneumococcal conjugate vaccines

Pleural effusion is a serious complication of pneumonia, and Streptococcus pneumoniae is a leading cause. We describe the aetiology of pneumonia with effusion among children in the Dominican Republic before the introduction of the 13-valent pneumococcal conjugate vaccine (PCV) in 2013 and the performance characteristics of a rapid immunochromatographic test (ICT) for detecting S. pneumoniae in pleural fluid. From July 2009 to June 2011, we enrolled children <15 years old admitted with pneumonia and pleural effusion to Robert Reid Cabral Children’s Hospital, Dominican Republic. Pleural fluid was tested by culture, polymerase chain reaction (PCR) for bacterial (S. pyogenes, S. pneumoniae) and viral (respiratory syncytial virus and human rhinovirus) pathogens, and by ICT for S. pneumoniae. We calculated the performance of ICT and culture compared with PCR. Among 121 cases, the median age was 31 months (range 1 week to 14 years). Pleural fluid culture (n = 121) and PCR testing (n = 112) identified an aetiology in 85 (70.2%) cases, including 62 S. pneumoniae (51.2%) and 19 Staphylococcus aureus (15.7%). The viruses tested were not detected. The most prevalent pneumococcal serotypes were 14 (n = 20), 1 (n = 13), and 3 (n = 12). Serotype coverage of the 10- and 13-valent PCVs would be 70.5% and 95.1%, respectively. The sensitivity of point-of-care ICT was 100% (95% confidence interval [CI] 94.1%–100%), while specificity was 86.3% (95% CI 73.7%–94.3%). S. pneumoniae caused more than half of paediatric pneumonia with effusion cases; introduction of PCV in the Dominican Republic could reduce the burden by 36–49%. ICT is a practical, valid diagnostic tool for clinical care and surveillance in settings with limited laboratory capacity.

Pediatric Pleural Empyema in the Province of Quebec: Analysis of a 10-Fold Increase Between 1990 and 2007

BACKGROUND

Although the frequency of pneumonia has decreased over time, an increase in pleural empyema has been observed in different settings worldwide. This study assessed the epidemiology of community-acquired pediatric pleural empyema in the province of Quebec through validation of cases found in a hospitalization discharge database.

METHODS

We used the national administrative database of hospitalization to identify children (6 months-14 years) hospitalized for pleural empyema or pleural effusion with drainage from January 1990 until December 2007 and reviewed their medical charts. Patients with pleural effusion secondary to chest trauma, thoracic surgery, malignancies, cardiac failure, or metabolic disorders were excluded.

RESULTS

Predictive positive value (PPV) of empyema code in any position among discharge diagnostics in the administrative database was 86.5% (95% confidence interval: 81.9%-90.3%). After chart revision, 292 met the inclusion criteria. Age-adjusted incidence of pleural empyema in the pediatric population increased from 0.23 in 1990 to 4.01/100,000 person-years in 2007. A bacterial pathogen was identified in 46.5%; Streptococcus pneumoniae (Sp) (42%) and S pyogenes (30%) were most frequent. There was no obvious change in the PPV and proportions of children with chronic disease or asthma and in identified pathogens over time, but an increase in pre-admission respiratory symptoms duration (from 3.8 days to 5.7) and nonsteroidal anti-inflammatory drug use (from 0% to 19%) was observed.

CONCLUSIONS

From 1990 to 2007, we observed a 10-fold increase in the incidence of pediatric hospitalizations associated with pleural empyema. This increase preceded the introduction of a pneumococcal conjugated vaccine program in Quebec. Sp remained the major pathogen identified.

Treatment trends and outcomes in US hospital stays of children with empyema

BACKGROUND

Recently published practice guidelines continue to reflect uncertainty about the comparative effectiveness of various treatments for empyema in children. We describe treatment trends and outcomes in pediatric empyema using the most current nationally representative data.

METHODS

Using survey methods and Kids' Inpatient Databases from 1997 to 2009, we evaluated hospital stays in children 0-18 years of age. We used 2009 data to compare transfer-out rates and lengths of stay across various types of treatment, after adjusting for patient and hospital factors.

RESULTS

From 1997 to 2009, empyema discharges steadily increased from 3.1 to 6.0 per 100,000 children (P < 0.001 for trend) and also were increasingly likely (P < 0.01) to be coded for: (1) at least 1 pleural drainage procedure (76.4-83.2%), (2) multiple drainage procedures (36.0-41.6%) and (3) home health care (8.7-15.0%). By 2009, video-assisted thoracoscopic surgery was more commonly coded than chest tube drainage and was associated with a lower transfer-out rate (0.6% vs. 10.1%, adjusted P < 0.001) but no reduction in mean length of stay [11.2 vs. 13.4 days, adjusted incidence rate ratio 0.95 (95% confidence interval: 0.88-1.04)] for children neither admitted nor discharged by transfer.

CONCLUSIONS

US hospital stays for empyema in children not only continued to increase through 2009 but were also characterized by more intense procedural management. Outcomes results in this population-based study are consistent with practice guidelines and recommendations that recently endorsed chest tube drainage as an acceptable first treatment option for most children with empyema.

The increasing incidence of empyema

PURPOSE OF REVIEW

The aim of this review is to highlight recent changes concerning the incidence of empyema. In this article we have focused on community-acquired empyema

RECENT FINDINGS

The incidence of empyema seems to have been increasing both in children and adults worldwide in the past decades, mainly in healthy young adults and in older patients. The bacteriology of pleural infection is changing as well. In children, the most common microorganism that causes empyema continues to be Streptococcus pneumoniae. Interestingly, the widespread use of the seven valent conjugate vaccine has produced a replacement phenomenon with the emergence of some pneumococcal serotypes such as serotypes 1, 3 and 19A, which have a higher propensity to cause empyema. Moreover increases in the incidence of empyema due to Staphylococcus aureus have also been observed. In adults, increases in the rate of empyema due to Streptococcus milleri group and S. aureus have been reported.

SUMMARY

Continued surveillance in the epidemiology of empyema is needed. Progress in new strategies of prevention, such as a new generation of conjugate pneumococcal vaccines and protein-based vaccines, could become an important step in the control of this important complication.

Pneumococcal vaccines and the prevention of community-acquired pneumonia

Community-acquired pneumonia (CAP) is a disease that frequently affects children and adults throughout the world. As it places a considerable burden on society and, particularly, healthcare resources, any means of reducing its incidence and impact arouses great interest. A substantial number of paediatric and adult CAP cases are due to Streptococcus pneumoniae but, fortunately, there are effective vaccines available that are likely to have a significant impact on CAP-related medical, social and economic problems. The main aim of this paper is to evaluate the published evidence concerning the impact of pneumococcal vaccines on CAP in children and adults. The original 7-valent pneumococcal conjugate vaccine (PCV-7) completely modified the total burden of pneumococcal diseases in vaccinated children and unvaccinated contacts of any age. However, the existence of some problems moderately reducing its preventive efficacy has led to the development of PCVs with a larger number of pneumococcal serotypes, including those that were previously of marginal importance but now cause of severe disease. It is reasonable to think that these PCVs (particularly PCV13, which includes all of the most important serotypes emerging since the introduction of PCV7) will further reduce the importance of pneumococcal diseases, although it is still not clear whether the replacement of the 23-valent polysaccharide vaccine with PCV13 would be more protective in adults.

Pneumococcal empyema and complicated pneumonias: global trends in incidence, prevalence, and serotype epidemiology

This review evaluates the serotype epidemiology of complicated pneumococcal pneumonia (CPP) during the period 1990–2012. PubMed and EMBASE were searched using the terms “empyema”, “complicated pneumonia”, “pleural infection”, “necrotizing pneumonia”, “pleural effusion”, “parapneumonic effusion”, “pneumatocele”, or “lung abscess”; “pneumococcal” or “Streptococcus pneumoniae”; and “serotype” for studies on the epidemiology of complicated pneumonias published from January 1, 1990 to October 1, 2013. Studies with data on incidence and serotypes were included; reviews, case reports, and conference abstracts were excluded. Of 152 papers, 84 fitted the inclusion criteria. A few pneumococcal serotypes were predominant causes of CPP, particularly serotypes 1, 19A, 3, 14, and 7F. CPP was a more common manifestation of pneumococcal disease among older (>2 years old) than younger children. The data support increases in both reported incidence rates and proportions of CPP in children and adults during the period 1990–2012; specific increases varied by geographic region. The proportions of serotype 3 and, particularly in Asia, serotype 19A CPP have increased, whereas most studies show declines in serotype 14. Serotype 1 has been a predominant cause of CPP since 1990, while antibiotic resistance was infrequent among serotype 1 isolates. The reported incidence and proportions of CPP among pneumonia cases steadily increased from 1990 to 2012. Several factors might account for these increases, including enhanced disease detection due to a higher index of suspicion, more sophisticated diagnostic assays, and changes in the prevalence of serotypes with capacity to invade the pleural space that were not targeted by the 7-valent pneumococcal conjugate vaccine (PCV7).

Pneumococcal aetiology and serotype distribution in paediatric community-acquired pneumonia

Community-acquired pneumonia (CAP) is a major cause of morbidity in children. This study estimated the proportion of children with pneumococcal CAP among children hospitalised with CAP in Belgium and describes the causative serotype distribution after implementation of the 7-valent pneumococcal conjugate vaccine. Children 0–14 years hospitalised with X-ray-confirmed CAP were prospectively enrolled in a multicentre observational study. Acute and convalescent blood samples were collected. Pneumococcal aetiology was assessed by conventional methods (blood or pleural fluid cultures with Quellung reaction capsular typing or polymerase chain reaction [PCR] in pleural fluid), and recently developed methods (real-time PCR in blood and World Health Organization-validated serotype-specific serology). A total of 561 children were enrolled. Pneumococcal aetiology was assessed by conventional methods in 539, serology in 171, and real-time PCR in blood in 154. Pneumococcal aetiology was identified in 12.2% (66/539) of the children by conventional methods alone but in 73.9% by the combination of conventional and recently developed methods. The pneumococcal detection rate adjusted for the whole study population was 61.7%. Serotypes 1 (42.3%), 5 (16.0%), and 7F(7A) (12.8%) were predominant. In conclusion, Streptococcus pneumoniae remains the predominant bacteria in children hospitalised for CAP in Belgium after implementation of 7-valent pneumococcal conjugate vaccine, with non-vaccine-serotypes accounting for the majority of cases. The use of recently developed methods improves diagnosis of pneumococcal aetiology.

Initial effects of the National PCV7 Childhood Immunization Program on adult invasive pneumococcal disease in Israel

Background

PCV7 was introduced as universal childhood vaccination in Israel in July 2009 and PCV13 in November 2010. Here we report data on adult invasive pneumococcal disease (IPD), two years post PCV7 implementation and before an expected effect of PCV13.

Methods

An ongoing nationwide active-surveillance (all 27 laboratories performing blood cultures in Israel), providing all blood & CSF S. pneumoniae isolates from persons >18 y was initiated in July 2009. Capture-recapture method assured reporting of >95% cases. All isolates were serotyped in one central laboratory. IPD outcome and medical history were recorded in 90%. Second year post PCV implementation is compared to the first year.

Results

During July 2009 to June 2011, 970 IPD cases were reported (annual incidence [/100,000] of 9.17 and 10.16 in the two consecutive years, respectively). Respective case fatality rates (CFRs) were 20% and 19.1%. Incidence of IPD and CFR increased with age and number of comorbidities. Incidence rate was significantly greater during the second winter, 7.79/100,000 vs. 6.14/100,000 in first winter, p = 0.004, with a non-significant decrease during summer months (3.02 to 2.48/100,000). The proportion of IPD cases due to PCV7-serotypes decreased from 27.5% to 13.1% (first to second year) (p<0.001). Yet, non-PCV13-strains increased from 32.7% to 40.2% (p = 0.017). The increase in non-PCV13-strains was highly significant in immunocompromised patients and to a lesser degree in non-immunocompromised at risk or in older patients (>64 y). Among younger/healthier patients serotype 5 was the major increasing serotype. Penicillin and ceftriaxone resistance decreased significantly in the second year.

Conclusions

While overall annual incidence of IPD did not change, the indirect effect of PCV7 vaccination was evident by the significant decrease in PCV7 serotypes across all age groups. Increase in non-VT13 strains was significant in immunocompromised patients. A longer follow-up is required to appreciate the full effect of infant vaccination on annual IPD.

The burden of invasive pneumococcal disease in children with underlying risk factors in North America and Europe

BACKGROUND

Characterisation of risk groups who may benefit from pneumococcal vaccination is essential for the generation of recommendations and policy.

METHODS

We reviewed the literature to provide information on the incidence and risk of invasive pneumococcal disease (IPD) in at-risk children in Europe and North America. The PubMed database was searched using predefined search terms and inclusion/exclusion criteria for papers reporting European or North American data on the incidence or risk of IPD in children with underlying medical conditions.

RESULTS

Eighteen references were identified, 11 from North America and 7 from Europe, with heterogeneous study methods, periods and populations. The highest incidence was seen in US children positive for human immunodeficiency virus infection, peaking at 4167 per 100,000 patient-years in 2000. Studies investigating changes in incidence over time reported decreases in the incidence of IPD between the late 1990s and early 2000s. The highest risk of IPD was observed in children with haematological cancers or immunosuppression. Overall, data on IPD in at-risk children were limited, lacking incidence data for a wide range of predisposing conditions. There was, however, a clear decrease in the incidence of IPD in at-risk children after the introduction of 7-valent pneumococcal conjugate vaccine into immunisation programmes, as previously demonstrated in the general population.

CONCLUSION

Despite the heterogeneity of the studies identified, the available data show a substantial incidence of IPD in at-risk children, particularly those who are immunocompromised. Further research is needed to determine the true risk of IPD in at-risk children, particularly in the post-PCV period, and to understand the benefits of vaccination and optimal vaccination schedules.

Systematic review of the effect of pneumococcal conjugate vaccine dosing schedules on prevention of pneumonia

BACKGROUND

Pneumonia is the leading cause of morbidity and mortality among children <5 years of age globally. Pneumococcal conjugate vaccines (PCVs) are known to provide protection against vaccine serotype pneumococcal pneumonia; uncertainty exists regarding the optimum PCV dosing schedule.

METHODS

We conducted a systematic review of studies published from 1994 to 2010 (supplemented post hoc with studies from 2011) documenting the effect of PCV dosing schedules on clinical and radiologically confirmed pneumonia, pneumococcal pneumonia and empyema among children of ages targeted to receive vaccine. Data on 2- and 3-dose schedules were included. Percent change of pneumonia incidence rates from baseline to most recent year post-PCV introduction was calculated.

RESULTS

We identified 42 primary citations that evaluated PCV schedules and pneumonia. Thirty-seven (88%) were from North America, Europe or Australia; 37 (88%) evaluated PCV7 and 1 (2%) PCV10. Two studies (both observational) compared multiple schedules within the study. We found evidence of reduced clinical and radiologically confirmed pneumonia incidence for all schedules, including 2+1 (1 nonrandomized trial, 5 observational studies), 3+0 (5 randomized trials, 2 observational studies) and 3+1 (5 clinical trials, 24 observational studies) schedules. The magnitude of disease impact did not differ among schedules. Evidence for impact on pneumococcal pneumonia and empyema varied.

CONCLUSIONS

All schedules (2+1, 3+0 and 3+1) reduced clinical and radiologically confirmed pneumonia. Quantifying differences in pneumonia disease impact between schedules was difficult due to heterogeneity among studies in design, case definition and population. These findings support World Health Organization recommendations for 3-dose schedules administered as either 3+0 or 2+1 regimens. Pneumonia impact data are still needed on expanded serotype PCV products, developing country settings and the role for a booster dose.

Diagnosis of pneumococcal pneumonia: current pitfalls and the way forward

Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. However, it can also asymptomatically colonize the upper respiratory tract. Because of the need to distinguish between S. pneumoniae that is simply colonizing the upper respiratory tract and S. pneumoniae that is causing pneumonia, accurate diagnosis of pneumococcal pneumonia is a challenging issue that still needs to be solved. Sputum Gram stains and culture are the first diagnostic step for identifying pneumococcal pneumonia and provide information on antibiotic susceptibility. However, these conventional methods are relatively slow and insensitive and show limited specificity. In the past decade, new diagnostic tools have been developed, particularly antigen (teichoic acid and capsular polysaccharides) and nucleic acid (ply, lytA, and Spn9802) detection assays. Use of the pneumococcal antigen detection methods along with biomarkers (C-reactive protein and procalcitonin) may enhance the specificity of diagnosis for pneumococcal pneumonia. This article provides an overview of current methods of diagnosing pneumococcal pneumonia and discusses new and future test methods that may provide the way forward for improving its diagnosis.