Bacteremic pneumococcal community-acquired pneumonia in children less than 5 years of age in Italy

Complicated pneumococcal pneumonia in the era of higher-valent pneumococcal conjugate vaccines: a systematic literature review and meta-analysis, 2001-2022

PURPOSE

To estimate pneumococcal conjugate vaccine (PCV) national program impact on pneumococcal complicated pneumonia (PnCP) based on changes in PnCP population-based incidence, PnCP proportion of all-cause complicated pneumonia (or invasive pneumococcal disease), and PnCP serotype distribution.

METHODS

MEDLINE, EMBASE, and Global Index Medicus articles (2001-March 2022) reporting laboratory-confirmed PnCP studies were stratified by age group, outcome measure, PCV program period(s) (pre-PCV, transition, and post-PCV), serotype distribution (based on serotyping methodology used), and PCV serotype formulation. Random effect meta-analysis of the total number of serotyped isolates within each study was used to calculate pooled serotype-specific percentages.

RESULTS

Of 1360 publications screened, the 134 studies included from 30 countries differed widely by methodological approaches. Pediatric PnCP incidence tended to decline from pre-PCV to post-PCV periods, as did PnCP as a proportion of all-cause complicated pneumonia from transition to post-PCV periods. Studies describing changes in serotype distribution by PCV program period applied detection methods that varied from pre-PCV period microbiological culture with Quellung serotyping to in the transition and post-PCV periods molecular methods like PCR. Meta-analysis revealed near elimination of pediatric PCV7-serotype PnCP between pre- and post-PCV, while the PCV13nonPCV7 percentage increased from 51.1% pre-PCV period to 76.5% in the transition period, remaining stable post-PCV period. Non-PCV13 serotypes increased slightly from low baseline numbers. Adult data were lacking or inconsistent.

CONCLUSIONS

Although studies were heterogeneous, pediatric PnCP incidence and proportion tended to decline from pre-PCV to post-PCV periods, and PCV13nonPCV7 serotype distribution percentage remained unchanged from transition to post-PCV period. Standardization of PnCP surveillance methods, definitions, and reporting is needed to evaluate accurately PCV program impact.

Necrotizing pneumonia among Italian children in the pneumococcal conjugate vaccine era

BACKGROUND

Necrotizing pneumonia (NP) is a severe complication of community-acquired pneumonia. The impact of 13-valent pneumococcal conjugate vaccine (PCV13) on the epidemiology of NP in children has not been assessed.

PATIENTS AND METHODS

Medical records of children less than 18 years admitted with NP to two pediatric hospitals in Italy between 2005 and 2019 were reviewed. The following four periods were defined: 2005-2010 (pre-PCV13), 2011-2013 (early post-PCV13), 2014-2016 (intermediate post-PCV13), and 2017-2019 (late post-PCV13).

RESULTS

Forty-three children (median age, 44 months) were included. Most of them (93%) were previously healthy. No differences in age, sex, season of admission, comorbidity, clinical presentation, or hospital course were identified between pre-PCV13 and post-PCV13 periods. A significant decrease in the rate of NP-associated hospitalizations was found between the early (1.5/1000 admissions/year) and the intermediate (0.35/1000 admissions/year) post-PCV13 period (p = .001). An increased trend in admissions was found thereafter. Streptococcus pneumoniae was the most common agent detected in both periods (pre-PCV13: 11/18, 61%; post-PCV13: 13/25, 52%). Serotype 3 was the most common strain in both periods (pre-PCV13: 3/11, 27%; post-PCV13; 4/13, 31%). There were no changes in the etiology over time, but most patients with Streptococcus pyogenes or Staphylococcus aureus infection were admitted during the post-PCV13 period.

CONCLUSIONS

The hospitalization rate for NP in children decreased a few years after the implementation of PCV13 immunization in Italy. However, an increased trend in admissions was found thereafter. S. pneumoniae was the most frequent causal agent in both pre- and post-PCV13 periods. Pneumococcal serotypes were mainly represented by Strain 3.

Complicated pneumonia in children

Complicated community-acquired pneumonia in a previously well child is a severe illness characterised by combinations of local complications (eg, parapneumonic effusion, empyema, necrotising pneumonia, and lung abscess) and systemic complications (eg, bacteraemia, metastatic infection, multiorgan failure, acute respiratory distress syndrome, disseminated intravascular coagulation, and, rarely, death). Complicated community-acquired pneumonia should be suspected in any child with pneumonia not responding to appropriate antibiotic treatment within 48-72 h. Common causative organisms are Streptococcus pneumoniae and Staphylococcus aureus. Patients have initial imaging with chest radiography and ultrasound, which can also be used to assess the lung parenchyma, to identify pleural fluid; CT scanning is not usually indicated. Complicated pneumonia is treated with a prolonged course of intravenous antibiotics, and then oral antibiotics. The initial choice of antibiotic is guided by local microbiological knowledge and by subsequent positive cultures and molecular testing, including on pleural fluid if a drainage procedure is done. Information from pleural space imaging and drainage should guide the decision on whether to administer intrapleural fibrinolytics. Most patients are treated by drainage and more extensive surgery is rarely needed; in any event, in low-income and middle-income countries, resources for extensive surgeries are scarce. The clinical course of complicated community-acquired pneumonia can be prolonged, especially when patients have necrotising pneumonia, but complete recovery is the usual outcome.

Value of Blood Cultures in the Management of Children Hospitalized with Community-Acquired Pneumonia

Background and objectives

Current guidelines for the management of community-acquired pneumonia (CAP) in children recommend obtaining a blood culture for children with moderate to severe pneumonia; yet, there is no guidance to assess the severity of the disease. Thus, a blood culture is obtained for the majority of children admitted with CAP, regardless of the severity of their symptoms. The study was designed to investigate and identify the prevalence of bacteremia in pediatric patients hospitalized with CAP and to evaluate the clinical and laboratory variables associated with bacteremia.

Methods

We conducted a medical record review of children aged from two months to 18 years diagnosed with CAP between January 1, 2013, and December 31, 2017, at our two urban tertiary centers. We used binary logistic regression analysis and chi-square tests to look at factors associated with blood culture positivity.

Results

A total of 464 patients were admitted with CAP. Blood cultures were obtained in 357 (76.9%) patients; 23 patients had repeated cultures. Fifteen patients had positive cultures: 5/380 (1.3%) were considered true positive results and 10/380 (2.6%) were considered contaminants. Intensive care unit (ICU) admission (OR 5.6 with 95% CI (1- 31), p<0.03), toxic appearance (OR 12.8 with 95% CI (1.3-125), p<0.01), and significantly elevated C-reactive protein (CRP) (>300 mg/L (p<0.01) were associated with bacteremia.

Conclusion

The prevalence of bacteremia among children admitted for CAP is low. The use of routine blood cultures should be reserved for children with moderate to severe pneumonia. Further studies are required to better risk-stratify children with CAP.

The Negative Predictive Ability of Immature Neutrophils for Bacteremia in Children With Community-Acquired Infections

Background: Bacteremia is a serious condition. We aimed to assess the role of immature neutrophils in peripheral blood smears for prediction of bacteremia in children. Methods: In this cross-sectional study conducted in Salvador, Brazil, blood cultures collected from patients aged ≤18 years were identified. White Blood Cell count (WBC) was performed upon admission. Medical charts were reviewed and cases from the community were included. Results: Out of 833 potentially eligible patients, 263 (31.6%) were excluded. Therefore, the study group comprised 570 patients being blood collected for culture upon admission from all of them and WBC performed upon admission from 566. The median age was 2 years (IQR: 9.4 mo-5 y) and 300 (52.6%) were male. Acute respiratory infection was the most frequent diagnosis (n = 388; 68.1%), being 250 (43.9%) lower (LRTI) and 138 (24.2%) upper respiratory tract infections. Blood culture was positive in 9 (1.6%; 95% CI: 0.8-2.9%) cases, out of which 7 (2.8%) had LRTI. Streptococcus pneumoniae (n = 3), Haemophilus (n = 2), Neisseria meningitidis, viridans streptococci, Streptococcus agalactiae, and Acinetobacter baumanii (n = 1 each) were isolated. The total WBC/mm3 did not differ when children with positive or negative blood culture were compared (12,100 [IQR: 6,950-15,250] vs. 11,000 [IQR: 7,900-14,900]; P = 0.9). However, presence of any immature neutrophil was significantly more frequent among patients with bacteremia in comparison with patients without bacteremia (100% [9/9] vs. 40% [223/557]; P < 0.001). The absolute number of immature neutrophils was significantly lower among children without bacteremia (0 [IQR: 0-259] vs. 325 [IQR: 275-1,106]; P < 0.001). Overall, the area under the ROC curve of the number of immature neutrophils in regard to bacteremia was 0.82 (95% CI: 0.76-0.88; P = 0.001). Among 413 patients with absolute number of immature neutrophils <242/mm³, none had bacteremia; among 153 patients with absolute number of immature neutrophils ≥242/mm³, 9 (5.9%) had bacteremia. Absolute number of immature neutrophils ≥242/mm3 showed: sensitivity 100% (95% CI: 71.7-100%), specificity 74.1% (95% CI: 70.4-77.7%), negative predictive value 100% (95% CI: 99.3-100.0%), and positive predictive value 5.9% (95% CI: 2.9-10.5%). When only children with LRTI were analyzed, the results were similar. Conclusion: The absolute number of immature neutrophils in peripheral blood smear is a potential tool to rule out bacteremia among children with community-acquired infections.

Microbiological Diagnosis of Respiratory Illness

A wide variety of microorganisms are potential respiratory pathogens, and the spectrum of known pathogens for each respiratory infection syndrome has not changed markers over recent years. Detection of likely etiologic agents of respiratory infections can help direct management and can also play an important role in disease surveillance. For this purpose, we are still reliant on many traditional diagnostic tools that have been used for decades in order to determine the microbial etiology of respiratory infections. However, these tools have been increasingly supplemented by newer methods, particular molecular diagnostic techniques, which have enabled the more rapid detection of many pathogens that were previously difficult to detect. These advances have particularly lead to improvements in the ability to detect respiratory viruses and also other microorganisms that do not normally colonize the respiratory tract. Recognition of the existence of the lung microbiome has challenged the traditional views of pneumonia pathogenesis and may provide the opportunity for new diagnostic tools that are focused on more than just detection of specific known pathogens. Continued liaison between clinicians and laboratory staff is vital in order to facilitate the most cost-effective use of laboratory diagnostics.

A three-step diagnosis of pediatric pneumonia at the emergency department using clinical predictors, C-reactive protein, and pneumococcal PCR

Recommendations for the management of community-acquired pneumonia (CAP) advocate that, in the absence of the clinical and laboratory findings typical of bacterial CAP, antibiotics are not required. However, the true value of the clinical and laboratory predictors of pediatric CAP still needs to be assessed. This prospective cohort study in three emergency departments enrolled 142 children with radiological pneumonia. Pneumonia with lung consolidation was the primary endpoint; complicated pneumonia (bacteremia, empyema, or pleural effusion) was the secondary endpoint. We showed that three clinical signs (unilateral hypoventilation, grunting, and absence of wheezing), elevated procalcitonin (PCT), C-reactive protein (CRP), negative nasopharyngeal viral PCR, or positive blood pneumococcal PCR (P-PCR) were significantly associated with both pneumonia with consolidation and complicated pneumonia. Children with negative clinical signs and low CRP values had a low probability of having pneumonia with consolidation (13%) or complicated pneumonia (6%). Associating the three clinical signs, CRP >80 mg/L and a positive P-PCR ruled in the diagnosis of complicated pneumonia with a positive predictive value of 75%.

CONCLUSION

A model incorporating clinical signs and laboratory markers can effectively assess the risk of having pneumonia. Children with negative clinical signs and low CRP are at a low risk of having pneumonia. For children with positive clinical signs and high CRP, a positive blood pneumococcal PCR can more accurately confirm the diagnosis of pneumonia. What is Known: • Distinguishing between bacterial and viral pneumonia in children is challenging. • Reducing the inappropriate use of antibiotics is a priority. What is New: • Children with negative clinical signs and low C-reactive protein (CRP) values have a low probability of having pneumonia. • Children with high CRP values can be tested using a pneumococcal PCR to rule in the diagnosis of pneumonia with a high positive predictive value.

Streptococcus pneumoniae pharyngeal colonization in school-age children and adolescents with cancer

Patients with cancer, particularly those with hematologic malignancies, are at an increased risk of invasive pneumococcal disease (IPD) and they are included in the list of subjects for whom pneumococcal vaccination is recommended. The main aim of this study was to evaluate Streptococcus pneumoniae colonization in school-aged children and adolescents with cancer to determine the potential protective efficacy of 13-valent pneumococcal conjugate vaccine (PCV13). An oropharyngeal swab was obtained from 277 patients (age range 6-17 years) with cancer during routine clinical visits and analyzed for S. pneumoniae using real-time polymerase chain reaction. S. pneumoniae was identified in 52 patients (18.8%), including 47/235 (20.0%) with hematologic malignancies and 5/42 (11.9%) with solid tumors. Colonization declined significantly with an increase in age (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.16-0.71, and OR 0.30, 95% CI 0.11-0.82 in children aged 10-14 and ≥15 years, respectively, as compared to those <10 years). Carriage was more common among patients with leukemia or lymphoma than in children with solid tumors. Co-trimoxazole prophylaxis was significantly associated with reduced pneumococcal carriage (OR 0.41, 95% CI 0.19-0.89). A total of 15/58 (25.9%) and 26/216 (12.0%) children were colonized by PCV13 serotypes among cancer patients previously vaccinated and not vaccinated with 7-valent pneumococcal conjugate vaccine (PCV7), respectively. In conclusion, this study indicates that children and adolescents with cancer are frequently colonized by S. pneumoniae. Because most of the carried serotypes are included in PCV13, this vaccine is presently the best solution to reduce the risk of IPD in these patients.

Sensitivity and Specificity of Soluble Triggering Receptor Expressed on Myeloid Cells-1, Midregional Proatrial Natriuretic Peptide and Midregional Proadrenomedullin for Distinguishing Etiology and to Assess Severity in Community-Acquired Pneumonia

Study Design

This study aimed to evaluate the diagnostic accuracy of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), midregional proatrial natriuretic peptide (MR-proANP) and midregional proadrenomedullin (MR-proADM) to distinguish bacterial from viral community-acquired pneumonia (CAP) and to identify severe cases in children hospitalized for radiologically confirmed CAP. Index test results were compared with those derived from routine diagnostic tests, i.e., white blood cell (WBC) counts, neutrophil percentages, and serum C-reactive protein (CRP) and procalcitonin (PCT) levels.

Methods

This prospective, multicenter study was carried out in the most important children’s hospitals (n = 11) in Italy and 433 otherwise healthy children hospitalized for radiologically confirmed CAP were enrolled. Among cases for whom etiology could be determined, CAP was ascribed to bacteria in 235 (54.3%) children and to one or more viruses in 111 (25.6%) children. A total of 312 (72.2%) children had severe disease.

Results

CRP and PCT had the best performances for both bacterial and viral CAP identification. The cut-off values with the highest combined sensitivity and specificity for the identification of bacterial and viral infections using CRP were ≥7.98 mg/L and ≤7.5 mg/L, respectively. When PCT was considered, the cut-off values with the highest combined sensitivity and specificity were ≥0.188 ng/mL for bacterial CAP and ≤0.07 ng/mL for viral CAP. For the identification of severe cases, the best results were obtained with evaluations of PCT and MR-proANP. However, in both cases, the biomarker cut-off with the highest combined sensitivity and specificity (≥0.093 ng/mL for PCT and ≥33.8 pmol/L for proANP) had a relatively good sensitivity (higher than 70%) but a limited specificity (of approximately 55%).

Conclusions

This study indicates that in children with CAP, sTREM-1, MR-proANP, and MR-proADM blood levels have poor abilities to differentiate bacterial from viral diseases or to identify severe cases, highlighting that PCT maintains the main role at this regard.

Measurement of lipocalin-2 and syndecan-4 levels to differentiate bacterial from viral infection in children with community-acquired pneumonia

Background

In this study, we evaluated the lipocalin-2 (LIP2) and syndecan-4 (SYN4) levels in children who were hospitalized for radiologically confirmed CAP in order to differentiate bacterial from viral infection. The results regarding the LIP2 and SYN4 diagnostic outcomes were compared with the white blood cell (WBC) count and C reactive protein (CRP) levels.

Methods

A total of 110 children <14 years old who were hospitalized for radiologically confirmed CAP were enrolled. Serum samples were obtained upon admission and on day 5 to measure the levels of LIP2, SYN4, and CRP as well as the WBC. Polymerase chain reaction of the respiratory secretions and tests on blood samples were performed to detect respiratory viruses, Streptococcus pneumoniae, and Mycoplasma pneumoniae.

Results

CAP was considered to be due to a probable bacterial infection in 74 children (67.3 %) and due to a probable viral infection in 16 children (14.5 %). Overall, 84 children (76.4 %) were diagnosed with severe CAP. The mean values of the WBC count and the LIP2 and SYN4 levels did not differ among the probable bacterial, probable viral, and undetermined cases. However, the CRP serum concentrations were significantly higher in children with probable bacterial CAP than in those with probable viral disease (32.2 ± 55.5 mg/L vs 9.4 ± 17.0 mg/L, p < 0.05). The WBC count was the best predictor of severe CAP, but the differences among the studied variables were marginal. The WBC count was significantly lower on day 5 in children with probable bacterial CAP (p < 0.01) and in those with an undetermined etiology (p < 0.01). The CRP and LIP2 levels were significantly lower 5 days after enrollment in all of the studied groups, independent of the supposed etiology of CAP (p < 0.01 for all comparisons). No statistically significant variation was observed for SYN4.

Conclusions

Measuring the LIP2 and SYN4 levels does not appear to solve the problem of the poor reliability of routine laboratory tests in defining the etiology and severity of pediatric CAP. Currently, the CRP levels and WBC, when combined with evaluation of clinical data, can be used to limit the overuse of antibiotics as much as possible and to provide the best treatment to the patient.

Bacteremic Pneumonia before and after Withdrawal of 13-Valent Pneumococcal Conjugate Vaccine from a Public Vaccination Program in Spain: A Case-Control Study

OBJECTIVE

To compare the incidence and epidemiology of bacteremic community-acquired pneumonia (CAP) in the setting of changes in 13-valent pneumococcal conjugate vaccine (PCV13) coverage.

STUDY DESIGN

In the region of Madrid, universal immunization with the PCV13 started in May 2010. In July 2012, public funding ceased. Vaccination coverage decreased from >95% to 82% in 2013 and to 67% in 2014. We performed a multicenter surveillance and case-control study from 2009-2014. Cases were hospitalized children with bacteremic CAP. Controls were children selected 1:1 from next-admitted with negative blood cultures and typical, presumed bacterial CAP.

RESULTS

Annual incidence of bacteremic CAP declined from 7.9/100,000 children (95% CI 5.1-11.1) in 2009 to 2.1/100,000 children (95% CI 1.1-4.1) in 2012. In 2014, 2 years after PCV13 was withdrawn from the universal vaccination program, the incidence of bacteremic CAP increased to 5.4/100,000 children (95% CI 3.5-8.4). We enrolled 113 cases and 113 controls. Streptococcus pneumoniae caused most of bloodstream infections (78%). Empyema was associated with bacteremia (P = .003, OR 3.6; 95% CI 1.4-8.9). Simple parapneumonic effusion was not associated with bacteremia. Incomplete PCV immunization was not a risk factor for bacteremic pneumonia.

CONCLUSIONS

High rate of PCV13 immunization was associated with decreased incidence of bacteremic CAP; this incidence increased when rate of immunization fell. Empyema (but not parapneumonic pleural effusion) was associated with bacteremia.

How recent advances in molecular tests could impact the diagnosis of pneumonia

Molecular diagnostic tests have been the single major development in pneumonia diagnostics over recent years. Nucleic acid detection tests (NATs) have greatly improved the ability to detect respiratory viruses and bacterial pathogens that do not normally colonize the respiratory tract. In contrast, NATs do not yet have an established role for diagnosing pneumonia caused by bacteria that commonly colonize the nasopharynx due to difficulties discriminating between pathogens and coincidental carriage strains. New approaches are needed to distinguish infection from colonization, such as through use of quantitative methods and identification of discriminating cut-off levels. The recent realization that the lung microbiome exists has provided new insights into the pathogenesis of pneumonia involving the interaction between multiple microorganisms. New developments in molecular diagnostics must account for this new paradigm.

Streptococcus pneumoniae oropharyngeal colonization in school-age children and adolescents with type 1 diabetes mellitus: Impact of the heptavalent pneumococcal conjugate vaccine

This study evaluated Streptococcus pneumoniae colonization in children and adolescents with type 1 diabetes mellitus (DM1) to investigate the theoretical risk of invasive pneumococcal disease (IPD) in these patients and the potential protective efficacy of pneumococcal conjugate vaccines (PCVs). An oropharyngeal swab was obtained from 299 patients aged 6-17 y with DM1 who were enrolled during routine clinical visits. DNA from swabs was analyzed for S. pneumoniae using real-time polymerase chain reaction. S. pneumoniae was identified in the swabs of 148 subjects (49.8%). Colonization was strictly age-related and declined significantly in the group aged ≥15 years (odds ratio [OR] 0.28; 95% confidence interval [CI], 0.14-0.57). Carriage was also significantly influenced by sex (lower in females: OR 0.56; 95% CI, 0.35-0.91), ethnicity (less common among non-Caucasians: OR 0.34; 95% CI, 0.13-0.89), parental smoking habit (more frequent among children with at least one smoker between parents: OR 1.76; 95% CI, 0.90-2.07), and the administration of antibiotic therapy in the previous 3 months (less frequent among patients who received antibiotics: OR 0.21; 95% CI, 0.07-0.62). Multivariate analyses of the entire study population showed no association between carriage and PCV7 vaccination status. Serotypes 19F, 9V, and 4 were the most frequently identified serotypes. In conclusion, school-age children and adolescents with DM1 are frequently colonized by S. pneumoniae, and protection against pneumococcal carriage following infant and toddler vaccination was not effective after several years. Together with the need to increase vaccine uptake in all the children aged <2 years, these results suggest that PCV booster doses are needed in DM1 patients to maintain the protection offered by these vaccinations.

The impact of heptavalent pneumococcal conjugate vaccine on the incidence of childhood community-acquired pneumonia and bacteriologically confirmed pneumococcal pneumonia in Japan

Heptavalent pneumococcal conjugate vaccine (PCV7) was introduced to Japan in 2010. We investigated the impact of PCV7 on childhood community-acquired pneumonia (CAP) and pneumococcal pneumonia (PP). Children aged <5 years living in Chiba city, Japan, who were admitted to hospitals were enrolled to estimate the incidence of CAP based on the mid-year population. PP was determined by the presence of Streptococcus pneumoniae in cultured blood and/or sputum samples of CAP patients. The incidence of CAP and S. pneumoniae isolated from PP patients was compared before (April 2008-March 2009) and after (April 2012-March 2013) the introduction of PCV7 immunization. The annual incidence of CAP was reduced [incidence rate ratio 0·81, 95% confidence interval (CI) 0·73-0·90]. When comparing post-vaccine with pre-vaccine periods, the odds ratio for PP incidence was 0·60 (95% CI 0·39-0·93, P = 0·024). PCV7-covered serotypes markedly decreased (66·6% in pre-vaccine vs. 15·6% in post-vaccine, P < 0·01), and serotypes 6C, 15A, 15C and 19A increased. Multidrug-resistant international clones in the pre-vaccine period (Spain6B-2/ST90, Taiwan19F-14/ST236) decreased, while Sweden15A-25/ST63 was the dominant clone in the post-vaccine period. A significant reduction in the incidence of both CAP hospitalizations and culture-confirmed PP of vaccine serotypes was observed at 2 years after PCV7 vaccination.

Impact of PCV7/PCV13 introduction on community-acquired alveolar pneumonia in children <5 years

BACKGROUND

Alveolar community-acquired pneumonia (A-CAP) is mostly considered a bacterial disease, mainly pneumococcal. This study was conducted to document the impact of sequential 7-valent and the 13-valent pneumococcal conjugate vaccines (PCV7; PCV13) on emergency room and hospitalization for A-CAP among children <5 years of age.

METHODS

This is an ongoing prospective population-based study in southern Israel. The current analysis spans over the period July 2002 through June 2013. A-CAP was defined using the World Health Organization (WHO)'s criteria for radiologically-confirmed pneumonia. PCV7 was introduced in Israel in July 2009 and gradually replaced by PCV13 in November 2010. Pneumococcal conjugate vaccine (PCV) impact was calculated by comparing incidences during 3 pre-defined periods: pre-PCV (2002-2008), PCV7 (2010-2011) and PCV13 (2012-2013).

RESULTS

Overall, 10,142 A-CAP episodes occurred. The annual incidences (per 1,000 inhabitants) in children <5 years old declined from a mean (±standard deviation) of 13.8 ± 0.9 in the pre-PCV period to 11.2 ± 2.7 in the PCV7 period and 7.4 in the PCV13 period, representing a reduction of 13% and 47%, respectively. The overall decrease was significantly faster among outpatients than among hospitalized children (42% and -8%, respectively in the PCV7 period; 68% vs. 32% in hospitalized children in the PCV13 period). While in children 12-23 months a significant decline was observed during the PCV7 and PCV13 periods, significant declines in A-CAP rates were observed only during the PCV13 period in the <12 months and 24-59 months age groups (44% and 46%, respectively).

CONCLUSIONS

A moderate decline in hospital A-CAP visits in children <5 years old was observed after PCV7 introduction. In contrast, after PCV13 introduction a substantial reduction in all visits was evident.

Differential impact of pneumococcal conjugate vaccines on bacteremic pneumonia versus other invasive pneumococcal disease

BACKGROUND

Bacteremic pneumonia (BP) accounts for ~35% of invasive pneumococcal disease (IPD) in young children. Our aims were to compare age, seasonal and serotype distribution of BP versus non-BP IPD and to determine whether the impact of the sequential 7/13-valent pneumococcal conjugate vaccine (PCV7/PCV13) introduction on disease incidence differed between BP and non-BP IPD in children <5 years of age.

METHODS

A nationwide, prospective, population-based, active surveillance (July 2004-June 2013) was conducted. All IPD episodes were included. PCV7 was introduced to the Israeli National Immunization Plan in July 2009 and has been replaced by PCV13 since November 2010.

RESULTS

In all, 983 (36.8%) BP and 1687 (63.2%) non-BP IPD episodes were recorded. A higher proportion of BP than that of non-BP IPD episodes (42.0% vs. 20.7%; P < 0.001) occurred in children >24 months old. Seasonality differed between BP and non-BP IPD, with yearly earlier peaks of non-BP IPD. The proportion of the 5 additional PCV13 serotypes (1, 3, 5, 7F and 19A) was higher in children with BP versus non-BP IPD (39.6% vs. 23.6%; P < 0.01). Shortly after PCV7 introduction, non-BP IPD rate was significantly reduced but that of BP was not. However, PCV13 introduction resulted in rapid reduction of BP rate, with a further reduction of non-BP IPD.

CONCLUSION

The differences in age distribution, seasonality and serotype distribution between BP and non-BP IPD suggest that the pathogenesis of these 2 entities is not identical and resulted in different impact rate dynamics after PCV7 and PCV13 introduction.

Improvement methodology increases guideline recommended blood cultures in children with pneumonia

BACKGROUND AND OBJECTIVE

A national evidence-based guideline for the management of community-acquired pneumonia (CAP) in children recommends blood cultures for patients admitted with moderate to severe illness. Our primary aim was to increase ordering of blood cultures for children hospitalized with CAP from 53% to 90% in 6 months. The secondary aim was to evaluate the effect of obtaining blood cultures on length of stay (LOS).

METHODS

At a tertiary children's hospital, interventions to increase blood cultures focused on 3 key drivers and were tested separately in the emergency department and inpatient units by using multiple plan-do-study-act cycles. The impact of the interventions was tracked over time on run charts. The association of ordering blood cultures and LOS was estimated by using linear regression models.

RESULTS

Within 6 months, the percentage of patients admitted with CAP who had blood cultures ordered increased from 53% to 100%. This change has been sustained for 12 months. Overall, 239 (79%) of the 303 included patients had a blood culture ordered; of these, 6 (2.5%) were positive. Patients who had a blood culture did not have an increased LOS compared with those without a blood culture.

CONCLUSIONS

Quality improvement methods were used to increase adherence to evidence-based national guidelines for performing blood cultures on children hospitalized with CAP; LOS did not increase. These results support obtaining blood cultures on all patients admitted with CAP without negative effects on LOS in a setting with a reliably low false-positive blood culture rate.

Pharyngeal colonization by Streptococcus pneumoniae in older children and adolescents in a geographical area characterized by relatively limited pneumococcal vaccination coverage

BACKGROUND

The aim of this study was to evaluate the relation between colonization and vaccination status with pneumococcal conjugate vaccine (PCV) in older children and adolescents living in an area characterized by relatively limited vaccination coverage.

METHODS

Oropharyngeal swabs were obtained from 2076 randomly selected healthy school-age children and adolescents, and the extracted genomic DNA was tested for Streptococcus pneumoniae by means of real-time polymerase chain reaction. All of the positive cases were subsequently serotyped, and the association between vaccination status with the heptavalent PCV (PCV7) and pneumococcal colonization was determined.

RESULTS

S. pneumoniae was identified in the oropharyngeal swabs of 1201 subjects (57.9%), and its prevalence declined with age (74.9% in subjects aged <10 years, 51.8% in those aged 10-14 years and 32.7% in those aged ≥15 years; P < 0.001). There were more carriers of any pneumococcal serotype, any of the serotypes in PCV7, or any of the 6 additional serotypes in 13-valent PCV (PCV13) among the vaccinated than the unvaccinated subjects, but no association emerged after adjustment for age and other selected covariates. Sub-analyses by serotype and age groups revealed significant differences in the case of serotypes 3 and 19A among children aged <10 years (odds ratios of 2.03 and 2.18, respectively).

CONCLUSIONS

These results show the absence of any long-term effect of PCV7 on colonization, and raise doubts concerning the recent suggestion to use carriage to evaluate the efficacy of PCVs. The high prevalence of carriers in all of the age groups independent of previous pneumococcal vaccination indicates that further studies are needed to evaluate whether the extensive use of PCVs in healthy older children and adolescents might reduce pharyngeal colonization of these subjects thereby increasing herd immunity.

Streptococcus pneumoniae and Staphylococcus aureus carriage in healthy school-age children and adolescents

Streptococcus pneumoniae and Staphylococcus aureus are common commensals of the upper respiratory tract in children and adolescents. Understanding the relationship between these two pathogens, including their potential for mutual interference, is needed to evaluate the epidemiology of the diseases they cause, the factors that condition acquisition and carriage, and the impact of related preventative measures. We obtained oropharyngeal and nasal swabs from 497 healthy subjects aged 6-17 years. S. pneumoniae detection and serotyping were performed using a real-time PCR and S. aureus detection was performed using the RIDAGENE MRSA system. We found that 136 (27.3%) of the children were carriers of both species, 121 (24.3%) of the children carried S. pneumoniae alone and 128 (25.7%) of the children carried S. aureus alone. S. aureus carriage was similar between children who carried S. pneumoniae (136/257, 52.9 %, 95% confidence interval [CI]: 46.8-58.9%) vs those who did not (128/240, 53.3%, 95% CI: 47.0 -59.5%) and was independent of age and vaccination with 7-valent pneumococcal conjugate vaccine (PCV7). Vaccination with PCV7 did not affect S. aureus carriage [S. pneumoniae: 84/143 (58.7%, 95% CI: 50.5 -66.5%) vaccinated children vs 171/351 (48.7%, 95% CI: 43.5 -53.9%) unvaccinated children; S. aureus: 67/143 (46.9%, 95% CI: 38.9-55.0 %) vaccinated children vs 195/351 (55.6%, 95% CI: 50.3 -60.7%) unvaccinated children]. Pneumococcal serotype also did not appear to affect S. aureus carriage. These findings suggested that the carriage of S. pneumoniae did not affect that of S. aureus in older children and adolescents, regardless of age, PCV7 vaccination and pneumococcal serotype.

Differentiation between mycoplasma and viral community-acquired pneumonia in children with lobe or multi foci infiltration: a retrospective case study

OBJECTIVES

To analyse the clinical features, inflammatory markers and radiographs of community-acquired pneumonia (CAP) cases with lobe or multi foci infiltration; with a special focus on factors which allow the differential diagnosis of viral and mycoplasma pneumonia.

SETTING

Retrospective chart review of CAP cases in a large university teaching hospital.

PARTICIPANTS

126 paediatric CAP cases, with lobe or multi foci infiltration, presenting between May 2012 and April 2013. Demographic data, clinical presentation on admission or referral, laboratory tests, prior history, and radiography were collected for each case if available.

PRIMARY AND SECONDARY OUTCOME MEASURES

We used univariate and multivariate logistic regression to determine the significant factors which allow the differential diagnosis of viral and mycoplasma CAP with lobe or multi foci infiltration.

RESULTS

There were 71 (56%) male and 55 (44%) female CAP cases with lobar or multi foci infiltration. 70 pneumonia cases were caused by Mycoplasma pneumoniae and 18 by viruses. Univariate analysis of the mycoplasma and viral causes of the CAP revealed that increased respiratory rate, wheeze, male gender and lymphocyte percentage were the factors associated with the differentiation of mycoplasma and viral aetiologies of pneumonia (p<0.05). A stepwise logistic regression analysis was performed to assess independent factors which allow the differential diagnosis of viral and mycoplasma pneumonia. Increased respiratory rate, wheeze, and lymphocyte percentage were reliable independent factors which allow the differential diagnosis of viral and mycoplasma CAP with lobar or multi foci infiltration.

CONCLUSIONS

Whether the CAP with lobar or multi foci infiltration was caused by mycoplasma species or viruses could not be inferred from the radiological patterns. Wheeze, lymphocyte percentage and respiratory rate were independent factors which allowed the differential diagnosis of viral and mycoplasma CAP with lobar or multi foci infiltration.

Seasonality of both bacteremic and nonbacteremic pneumonia coincides with viral lower respiratory tract infections in early childhood, in contrast to nonpneumonia invasive pneumococcal disease, in the pre-pneumococcal conjugate vaccine era

We assessed the seasonality of viral lower respiratory tract infections (V-LRI), bacteremic pneumonia, nonbacteremic pneumonia and nonpneumonia invasive pneumococcal diseases (IPD) in the pre-PCV era. Both bacteremic and nonbacteremic pneumonia seasonality peaked in winter, coinciding with V-LRI seasonality, whereas non-pneumonia IPD peaked in autumn before V-LRI increase, suggesting different pathogenesis.

Characterization of Streptococcus pneumoniae clones from paediatric patients with cystic fibrosis

The role of Streptococcus pneumoniae in cystic fibrosis (CF) is poorly understood. The pneumococcal population has changed over time after the introduction of the heptavalent conjugate vaccine (PCV7) and, more recently, the 13-valent conjugate vaccine (PCV13). Although serotypes and clones causing invasive pneumococcal disease or colonizing healthy children have been extensively analysed, little is known so far on the serotypes and clones of pneumococci in CF patients. The aim of this work was to investigate serotypes, antibiotic susceptibilities, genotypes and biofilm production of CF pneumococcal isolates. Overall, 44 S. pneumoniae strains collected from 32 paediatric CF patients from January 2010 to May 2012 in a large Italian CF Centre were tested for antimicrobial susceptibility testing by Etest, serotyped by the Quellung reaction and genotyped by a combination of different molecular typing methods, including pbp gene restriction profiling, pspA restriction profiling and sequencing, PFGE and multilocus sequence typing. Biofilm production by pneumococcal strains was also assessed. Penicillin non-susceptibility was 16 %. High resistance rates (>56 %) were observed for erythromycin, clindamycin and tetracycline. The most frequent serotype recovered was serotype 3 (31.8 %). The coverage of PCV7 and PCV13 was 6.8 and 47.7 %, respectively. More than 80 % of CF strains belonged to Pneumococcal Molecular Epidemiology Network (PMEN) reference clones, the most common being Netherlands(3)-ST180 (28.2 %), and Greece(21)-30/ST193 (15.4 %). All strains produced biofilm in vitro, although with large variability in biofilm formation efficiency. No correlation was found between biofilm levels and serotype, clone or antibiotic resistance. The high isolation rate of antibiotic-resistant serotype 3 pneumococci from CF patients suggests that PCV13 could increase protection from pneumococcal colonization and infection.

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.

Oropharyngeal and nasopharyngeal sampling for the detection of adolescent Streptococcus pneumoniae carriers

Monitoring the dynamics of pneumococcal carriage makes it possible to evaluate the epidemiological characteristics of Streptococcus pneumoniae disease and the theoretical coverage offered by pneumococcal vaccines. It has been demonstrated that the nasopharyngeal (NP) sampling of respiratory secretions is superior to oropharyngeal (OP) sampling for identifying pneumococci carried by younger children, but adult data are conflicting and there are no published studies of adolescents. In order to compare the efficiency of OP and NP sampling in identifying and quantifying S. pneumoniae carriage in healthy adolescents, 2 swab samples were obtained from 530 adolescents aged 15-19 years, the first taken from the posterior pharyngeal wall through the mouth (OP) and the second through the nose (NP). Bacterial genomic DNA was tested for the autolysin-A-encoding gene (lytA) and wzg (cpsA) gene of S. pneumoniae in order to evaluate pneumococcal carrier status. All of the positive cases were serotyped. S. pneumoniae was identified in 35.8% of the OP swabs and 3.5% of the NP swabs (P<0.0001). The serotypes included in the 13-valent pneumococcal conjugate vaccine (PCV13) were found in all but two OP samples (98.9%) and only 64.7% of the NP samples (P<0.0001). The most frequently identified PCV13 serotype in both groups was 19F, followed by serotypes 5 and 9V. In conclusion, OP sampling appeared significantly more effective than NP sampling in identifying and characterizing pneumococcal carrier status in adolescents. This suggests that OP sampling should be used when evaluating the dynamics of pneumococcal carriage among adolescents and the theoretical coverage offered by PCV13.

Diagnostic features of community-acquired pneumonia in children: what's new?

AIM

To critically summarise the available data on diagnosis of CAP in children, focusing on the newest findings and on the need for new studies.

METHODS

Eighty studies on the diagnosis of paediatric community-acquired pneumonia were scrutinised.

RESULTS

We found no significant associations between the signs or symptoms and aetiology of pneumonia and concluded that chest radiographs remain controversial and real-time polymerase chain reaction appears more sensitive than blood cultures.

CONCLUSION

Antibiotic overuse could make it difficult to differentiate viral and bacterial causes. Molecular methods provide promising tools for diagnosing infection by atypical bacteria, but are expensive and should be used selectively.

Pneumococcal bacterial load colonization as a marker of mixed infection in children with alveolar community-acquired pneumonia and respiratory syncytial virus or rhinovirus infection

BACKGROUND

The main aim of this study was to evaluate whether nasopharyngeal Streptococcus pneumoniae colonization in children with alveolar community-acquired pneumonia (CAP) and respiratory syncytial virus (RSV) or rhinovirus (RV) infection indicates a mixed lung infection.

METHODS

The nasopharyngeal secretions of 530 children with radiographically confirmed CAP were tested using the Luminex x TAG respiratory virus panel fast assay. Real-time polymerase chain reaction for the autolysin-A (LytA) and wzg (cpsA) genes of S. pneumoniae was performed on the RSV- and RV-positive samples.

RESULTS

Sixty-five of the 126 RSV-positive children (51.6%) were colonized with S. pneumoniae. Mean bacterial load was significantly higher in the patients with alveolar involvement (4.54±1.47 log10 DNA copies/mL vs. 3.75±1.62 log10 DNA copies/mL; P=0.04). Serotypes 5 and 19A were almost exclusively identified in the children with RSV and alveolar CAP, although the difference was statistically significant only for serotype 19A (P=0.03). Eighty-three of the 134 RV-positive children (61.9%) were colonized with S. pneumoniae and again mean bacterial load was significantly higher in the patients with alveolar involvement (4.21±1.37 log10 DNA copies/mL vs. 3.41±1.47 log10 DNA copies/mL; P=0.03). Serotypes 1, 5 and 19A were more frequently identified in the children with RV and alveolar CAP, although the difference was statistically significant only for serotype 5 (P=0.04).

CONCLUSIONS

In children with alveolar CAP and RSV or RV infection, the determination of nasopharyngeal pneumococcal bacterial load and identification of the serotypes can contribute to the diagnosis of mixed lung infection.

Improving the Diagnosis, Management, and Outcomes of Children with Pneumonia: Where are the Gaps?

Pneumonia is the greatest contributor to childhood mortality and morbidity in resource-poor regions, while in high-income countries it is one of the most common reasons for clinic attendance and hospitalization in this age group. Furthermore, pneumonia in children increases the risk of developing chronic pulmonary disorders in later adult life. While substantial advances in managing childhood pneumonia have been made, many issues remain, some of which are highlighted in this perspective. Multiple studies are required as many factors that influence outcomes, such as etiology, patient characteristics, and prevention strategies can vary between and within countries and regions. Also, outside of vaccine studies, most randomized controlled trials (RCTs) on pneumonia have been based in resource-poor countries where the primary aim is usually prevention of mortality. Few RCTs have focused on medium to long-term outcomes or prevention. We propose different tiers of primary outcomes, where in resource-rich countries medium to long-term sequelae should also be included and not just the length of hospitalization and readmission rates.

Community-acquired pneumonia in children

Community-acquired pneumonia (CAP) remains a frequent cause of morbidity and mortality worldwide even in industrialised countries, and its incidence is highest among children aged <5 years. Over the last two years, three international guidelines have been updated with new evidence concerning the incidence, aetiology and management of childhood CAP, but there are still some major problems in standardisation. The main aim of this review is to consider the available data concerning the aetiology, diagnosis, evaluation of severity, and treatment of paediatric CAP. Analysis of the literature shows that there are a number of unanswered questions concerning the management of CAP, including its definition, the absence of a paediatric CAP severity score, the difficulty of identifying its aetiology, the emergence of resistance of the most frequent respiratory pathogens to the most widely used anti-infectious agents, and the lack of information concerning the changes in CAP epidemiology following the introduction of vaccines against respiratory pathogens. More research is clearly required in various areas, and further efforts are needed to increase vaccination coverage with the already available vaccines in order to reduce the occurrence of the disease.

Association between radiological findings and severity of community-acquired pneumonia in children

Background

There are few published data concerning radiological findings and their relationship with community-acquired pneumonia (CAP) severity. The aim if this study was to assess radiographic findings in children with CAP of different severity in order to evaluate whether some parameters are associated with severe CAP.

Methods

We analysed the characteristics of parenchymal densities in 335 chest radiographs of otherwise healthy children (173 males; mean age ± standard deviation, 7.5 ± 4.5 years) admitted to our Emergency Room for CAP. Upon admission, chest radiographs were obtained in the two standard projections, and the children with severe or mild/moderate CAP were compared in order to identify any correlations between CAP severity and the radiological findings.

Results

Seventy-six of the 335 enrolled children (22.7%) fulfilled the criteria for severe CAP. In comparison with the children with mild/moderate CAP, in severe CAP there was a significantly greater frequency of a bilateral multifocal distribution (p = 0.01), the simultaneous involvement of ≥3 sites (p = 0.007), and the involvement of the right hilum (p = 0.02). The same results were confirmed in the multiple logistic regression model.

Conclusions

This study shows that radiological findings such as a multifocal bilateral distribution, the simultaneous involvement of at least three sites, and right hilar consolidation are associated with severe CAP in otherwise healthy children, and could be considered markers of disease severity in children with CAP.

Impact of rhinovirus nasopharyngeal viral load and viremia on severity of respiratory infections in children

There are few and partially discordant data regarding nasopharyngeal rhinovirus (RV) load and viremia, and none of the published studies evaluated the two variables together. The aim of this study was to provide new information concerning the clinical relevance of determining nasopharyngeal viral load and viremia when characterising RV infection. Nasopharyngeal swabs were obtained from 251 children upon their admission to hospital because of fever and signs and symptoms of acute respiratory infection in order to identify the virus and determine its nasopharyngeal load, and a venous blood sample was taken in order to evaluate viremia. Fifty children (19.9 %) had RV-positive nasopharyngeal swabs, six (12 %) of whom also had RV viremia: RV-C in four cases (66.6 %), and RV-A and RV-B in one case each. The RV nasopharyngeal load was significantly higher in the children with RV viremia (p < 0.001), who also had a higher respiratory rate (p = 0.02), white blood cell counts (p = 0.008) and C-reactive protein levels (p = 0.006), lower blood O2 saturation levels (P = 0.005), and more often required O2 therapy (p = 0.009). The presence of RV viremia is associated with a significantly higher nasopharyngeal viral load and more severe disease, which suggests that a high nasopharyngeal viral load is a prerequisite for viremia, and that viremia is associated with considerable clinical involvement.

Aetiology of paediatric pneumonia after the introduction of pneumococcal conjugate vaccine

We describe the aetiology of community-acquired pneumonia in children before and after the introduction of the pneumococcal conjugate vaccination (PCV) programme in 2006.

Prospective studies were conducted in 2001–2002 (pre-vaccine) and 2009–2011 (post-vaccine) of children aged 0–16 years with radiologically confirmed pneumonia seen in hospital. Investigations included culture, serology, immunofluorescence antibody and urine antigen testing, with an increased use of PCR assays and expanded panels of pathogens in the post-vaccine study.

241 and 160 children were enrolled in the pre- and post-vaccine studies, respectively (73% aged <5 years). Identification of a causative pathogen was higher post-vaccination (61%) than pre-vaccination (48.5%) (p=0.019). Rates of bacterial infections were not different between post- and pre-vaccine studies (17.5% versus 24%, p=0.258). Viral (31%) and mixed (12.5%) infections were found more often post-vaccination (19.5%, p=0.021) than pre-vaccination (5%, p=0.015). Rates of identified pneumococcal infections were comparable between pre- and post-vaccine studies (14.7% versus 17.4%, p=0.557). Diagnosis of pneumococcal infection post-vaccination improved when PCR was used compared to culture (21.6% versus 6%, p=0.0004). Serotypes included in PCV13 but not PCV7 were identified in 75% (18 out of 24) post-vaccination.

Infection with nonvaccine pneumococcal serotypes continues to be a significant cause of pneumonia in children in the UK.

Aetiology of community-acquired pneumonia in children following a pneumococcal conjugate vaccination programmehttp://ow.ly/p9Wub

Advocacy for pneumonia prevention in Korea: a multi-dimensional program organised around World Pneumonia Day

There are limited examples of population-based approaches that engage a broad range of stakeholders for prevention of pneumonia. In 2010, a multi-dimensional public-private partnership was established around World Pneumonia Day (WPD) in Seoul, Korea and included the following components: a) formation of an expert advisory group, b) creation of educational materials tailored for lay persons, c) creation of a dedicated WPD internet website in the local language, d) organisation of a WPD venue in central Seoul, e) creation of video and social networking messages for wide distribution, and f) engagement of parents, health-care professionals, public health agencies and policymakers. This project directly engaged 7 expert health professionals, 5 national- and city-level health facilities, and parents from communities. The program reached out to 70,560 persons including 25,200 persons who were contacted in person at publicly-held WPD events. An educational video produced for WPD was aired in the Seoul subway and visible to several million persons riding subway lines that aired the pneumonia public service announcements over a two-month period (February to March, 2011). In addition, the Korean WPD website experienced 4,975 page views with 3,338 visitors and the micro blog associated with this site hosted 82 posts from site visitors. Based on participant numbers and contact volumes achieved in this project, the Korean WPD program was widely accepted and proved to be a highly effective in reaching a large audience to advocate for pneumonia prevention. One key to success of this program appears to be the unique public-private partnership around a major health issue. The methods and tools developed in this program have excellent potential for adaptation and application in other countries where pneumonia may be an under recognised problem among the general public.

Pneumococcal diagnosis and serotypes in childhood community-acquired pneumonia

The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced routinely in the UK from September 2006 and replaced by PCV13 in 2010. In a prospective study from 2009 to 2011 of 160 children aged ≤16 years with radiologically confirmed pneumonia, likely pneumococcal infections were identified in 26%. Detection of pneumococci was improved with polymerase chain reaction compared to culture (21.6% versus 6% of children tested, P = 0.0004). Where serotyping was possible, all (n = 23) were non-PCV7 but PCV13 serotypes; 1 (43.5%), 3 (21.7%), 7A/F, and 19A (17.4% each).

DNA bacterial load in children with bacteremic pneumococcal community-acquired pneumonia

This study was conducted to evaluate the association between pneumococcal DNA load and parapneumonic pleural effusion (PPE) in children with community-acquired pneumonia. Bacterial load was quantified and related to the presence of PPE with or without empyema in 72 otherwise healthy children aged ≤5 years who were hospitalised because of radiographically confirmed CAP and showed a real-time polymerase chain reaction that was positive for Streptococcus pneumoniae. The proportion of children with a high bacterial load (i.e. ≥265 DNA copies/mL) was larger among the subjects with PPE than those without it. Multivariate analysis showed that a high bacterial load was significantly associated with PPE (OR 8.65; 95% CI 1.10-67.8 vs a bacterial load of <125 copies/mL). Children with infection due to pneumococcal serotype 19A were at highest risk of developing PPE (OR 7.44; 95% CI 1.10-50.4 vs all other typeable serotypes). The patients with CAP due to pneumococcal serotypes that are not included in the 13-valent conjugate vaccine (PCV13) were more frequently affected by PPE than those with infections associated with serotypes included in the vaccine, except for serotype 19A. Bacterial loads of ≥265 DNA copies/mL are significantly associated with PPE, and serotype 19A is significantly associated with a high bacterial load and the development of PPE. The mean bacterial load of the patients with empyema was higher than that of patients with simple PPE. Although further studies are required, it seems that serotypes not included in PCV13 can play a major role in causing a higher bacterial load and PPE.

Pharmacotherapy for pneumococcal infections: an update

INTRODUCTION

The management of pneumococcal diseases still places a significant burden on medical and economic resources. The subjects at greatest risk of pneumococcal infections are children.

AREAS COVERED

The aim of this review is to analyse the best current therapeutic approach to pneumococcal resistance, taking into account the level of susceptibility of Streptococcus pneumoniae, and the pharmacokinetics and pharmacodynamics of different antibiotics in the various pneumococcal diseases.

EXPERT OPINION

Antibiotic treatment of a number of pneumococcal diseases remains difficult or impossible due to the presence of strains resistant to commonly used antibiotics. In children the problem is significantly more important than in adults due to the reduced number of licenced drugs for subjects in the first years of life. The new conjugate pneumococcal vaccines containing 10 (PCV10) and 13 serotypes (PCV13), which include most of the recently emerging strains, might reduce the incidence of pneumococcal infections and the circulation of resistant pathogens. However, it is likely that optimal results will only be reached after the development of effective vaccines based on conserved proteins that are capable of preventing all pneumococcal infections, regardless of the serotype of the causative organism.

Community-Acquired Pneumonia in the Conjugate Vaccine Era

Community-acquired pneumonia (CAP) remains one of the most common serious infections encountered among children worldwide. In this review, we highlight important literature and recent scientific discoveries that have contributed to our current understanding of pediatric CAP. We review the current epidemiology of childhood CAP in the developed world, appraise the state of diagnostic testing for etiology and prognosis, and discuss disease management and areas for future research in the context of recent national guidelines.

Toll-like receptor 3 gene polymorphisms and severity of pandemic A/H1N1/2009 influenza in otherwise healthy children

BACKGROUND

Toll-like receptors (TLRs) form an essential part of the innate immune system, which plays a fundamental role in rapidly and effectively controlling infections and initiating adaptive immunity. There are no published data concerning the importance of polymorphisms of TLRs in conditioning susceptibility to influenza or the severity of the disease. The aim of this study was to evaluate whether selected polymorphisms of TLR2, TLR3 and TLR4 influence the incidence and clinical picture of pandemic A/H1N1/2009 influenza.

RESULTS

The study involved 272 healthy children attending our Emergency Room for influenza-like illness (ILI), including 51 (18.8%) with pandemic A/H1N1/2009 influenza as revealed by real-time polymerase chain reaction, and 164 healthy controls examined after minor surgery. Genomic DNA was extracted from whole blood samples and five single-nucleotide polymorphisms (SNPs) were studied: TLR2 rs5743708, TLR3 rs5743313, TLR3 rs5743315, TLR4 rs4986790 and TLR4 rs4986791. The TLR3 rs5743313/CT polymorphism was found in all of the children with pneumonia and influenza infection, but in a significantly smaller number of those with A/H1N1/2009 influenza without pneumonia (<0.0001). TLR2, TLR3 rs5743315/AC and TLR4 polymorphisms were equally distributed in all of the groups regardless of the presence of the pandemic A/H1N1/2009 virus and clinical diagnosis. Viral load was comparable in all of the study groups.

CONCLUSIONS

There is a close relationship between the presence of TLR3 rs5743313/CT and an increased risk of pneumonia in children infected by the pandemic A/H1N1/2009 influenza virus.