Community-acquired pneumonia in children: what's old? What's new?

High specificity of metagenomic next-generation sequencing using protected bronchial brushing sample in diagnosing pneumonia in children

Background

Lower respiratory tract infections are the leading cause of morbidity and mortality in children worldwide. Timely and accurate pathogen detection is crucial for proper clinical diagnosis and therapeutic strategies. The low detection efficiency of conventional methods and low specificity using respiratory samples seriously hindered the accurate detection of pathogens.

Methods

In this study, we retrospectively enrolled 1,032 children to evaluate the performance of metagenomics next-generation sequencing (mNGS) using bronchoalveolar lavage fluid (BALF) sample and protected bronchial brushing (BB) sample in diagnosing pneumonia in children. In addition, conventional tests (CTs) were also performed.

Results

The specificity of BB mNGS [67.3% (95% CI 58.6%-75.9%)] was significantly higher than that of BALF mNGS [38.5% (95% CI 12.0%-64.9%)]. The total coincidence rate of BB mNGS [77.6% (95% CI 74.8%-80.5%)] was slightly higher than that of BALF mNGS [76.5% (95% CI 68.8%-84.1%)] and CTs [38.5% (95% CI 35.2%-41.9%)]. During the epidemics of Mycoplasma pneumoniae, the detection rate of M. pneumoniae in the >6-year group (81.8%) was higher than that in the 3-6-year (78.9%) and <3-year groups (21.5%). The highest detection rates of bacteria, fungi, and viruses were found in the <3-year, >6-year, and 3-6-year groups, respectively. mNGS detection should be performed at the duration of 5-7 days after the start of continuous anti-microbial therapy or at the duration of 6-9 days from onset to mNGS test.

Conclusions

This is the first report to evaluate the performance of BB mNGS in diagnosing pulmonary infections in children on a large scale. Based on our findings, extensive application of BB mNGS could be expected.

Biomarkers of viral and bacterial infection in rhinovirus pneumonia

Background

Rhinovirus (RV) is often detected in children hospitalized with pneumonia, but the role of RV in causing pneumonia is still unclear.

Methods

White blood cell count, C-reactive protein, procalcitonin, and myxovirus resistance protein A (MxA) levels were determined from blood samples in children (n = 24) hospitalized with radiologically verified pneumonia. Respiratory viruses were identified from nasal swabs by using reverse transcription polymerase chain reaction assays. Among RV-positive children, the cycle threshold value, RV subtyping by sequence analysis, and the clearance of RV by weekly nasal swabs were determined. RV-positive children with pneumonia were compared to other virus-positive children with pneumonia, and to children (n = 13) with RV-positive upper respiratory tract infection from a separate earlier study.

Results

RV was detected in 6 children and other viruses in 10 children with pneumonia (viral co-detections excluded). All RV-positive children with pneumonia had high white blood cell counts, plasma C-reactive protein or procalcitonin levels, or alveolar changes in chest radiograph strongly indicating bacterial infection. The median cycle threshold value for RV was low (23.2) indicating a high RV load, and a rapid clearance of RV was observed in all. Blood level of viral biomarker MxA was lower among RV-positive children with pneumonia (median 100 μg/L) than among other virus-positive children with pneumonia (median 495 μg/L, p = 0.034) or children with RV-positive upper respiratory tract infection (median 620 μg/L, p = 0.011).

Conclusions

Our observations suggest a true viral-bacterial coinfection in RV-positive pneumonia. Low MxA levels in RV-associated pneumonia need further studies.

Antibiotic Treatment Duration for Community-Acquired Pneumonia in Outpatient Children in High-Income Countries-A Systematic Review and Meta-Analysis

BACKGROUND

The optimal treatment duration of community-acquired pneumonia (CAP) in children has been controversial in high-income countries. We conducted a meta-analysis to compare short antibiotic treatment (3-5 days) with longer treatment (7-10 days) among children aged ≥6 months.

METHODS

On 31 January 2022, we searched PubMed, Scopus, and Web of Science databases for studies published in English from 2003 to 2022. We included randomized controlled trials focusing on antibiotic treatment duration in children with CAP treated as outpatients. We calculated risk differences (RDs) with 95% confidence intervals and used the fixed-effect model (low heterogeneity). Our main outcome was treatment failure, defined as need for retreatment or hospitalization within 1 month. Our secondary outcome was presence of antibiotic-related harms.

RESULTS

A total of 541 studies were screened, and 4 studies with 1541 children were included in the review. Three studies had low risk of bias, and one had some concerns. All 4 studies assessed treatment failures, and the RD was 0.1% (95% confidence interval, -3.0% to 2.0%) with high quality of evidence. Two studies (1194 children) assessed adverse events related to antibiotic treatment, and the RD was 0.0% (-5.0% to 5.0%) with moderate quality of evidence. The diagnostic criteria varied between the included studies.

CONCLUSIONS

A short antibiotic treatment duration of 3-5 days was equally effective and safe compared with the longer (current) recommendation of 7-10 days in children aged ≥6 months with CAP. We suggest that short antibiotic courses can be implemented in treatment of pediatric CAP.

Multistep antimicrobial stewardship intervention on antibiotic prescriptions and treatment duration in children with pneumonia

INTRODUCTION

The Italian antimicrobial prescription rate is one of the highest in Europe, and antibiotic resistance has become a serious problem with high costs and severe consequences, including prolonged illnesses, the increased period of hospitalization and mortality. Inadequate antibiotic prescriptions have been frequently reported, especially for lower respiratory tract infections (LRTI); many patients receive antibiotics for viral pneumonia or bronchiolitis or broad-spectrum antibiotics for not complicated community-acquired pneumonia. For this reason, healthcare organizations need to implement strategies to raise physicians' awareness about this kind of drug and their overall effect on the population. The implementation of antibiotic stewardship programs and the use of Clinical Pathways (CPs) are excellent solutions because they have proven to be effective tools at diagnostic and therapeutic levels.

AIMS

This study evaluates the impact of CPs implementation in a Pediatric Emergency Department (PED), analyzing antibiotic prescriptions before and after the publication in 2015 and 2019. The CP developed in 2019 represents an update of the previous one with the introduction of serum procalcitonin. The study aims to evaluate the antibiotic prescriptions in patients with community-acquired pneumonia (CAP) before and after both CPs (2015 and 2019).

METHODS

The periods analyzed are seven semesters (one before CP-2015 called PRE period, five post CP-2015 called POST 1-5 and 1 post CP-2019 called POST6). The patients have been split into two groups: (i) children admitted to the Pediatric Acute Care Unit (INPATIENTS), and (ii) patients evaluated in the PED and sent back home (OUTPATIENTS). We have analyzed all descriptive diagnosis of CAP (the assessment of episodes with a descriptive diagnosis were conducted independently by two pediatricians) and CAP with ICD9 classification. All antibiotic prescriptions for pediatric patients with CAP were analyzed.

RESULTS

A drastic reduction of broad-spectrum antibiotics prescription for inpatients has been noticed; from 100.0% in the PRE-period to 66.7% in POST1, and up to 38.5% in POST6. Simultaneously, an increase in amoxicillin use from 33.3% in the PRE-period to 76.1% in POST1 (p-value 0.078 and 0.018) has been seen. The outpatients' group's broad-spectrum antibiotics prescriptions decreased from 54.6% PRE to 17.4% in POST6. Both for outpatients and inpatients, there was a decrease of macrolides. The inpatient group's antibiotic therapy duration decreased from 13.5 days (PRE-period) to 7.0 days in the POST6. Antibiotic therapy duration in the outpatient group decreased from 9.0 days (PRE) to 7.0 days (POST1), maintaining the same value in subsequent periods. Overlapping results were seen in the ICD9 group for both inpatients and outpatients.

CONCLUSIONS

This study shows that CPs are effective tools for an antibiotic stewardship program. Indeed, broad-spectrum antibiotics usage has dropped and amoxicillin prescriptions have increased after implementing the CAP CP-2015 and the 2019 update.

Current perspectives on atypical pneumonia in children

The major pathogens that cause atypical pneumonia are Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila. Community-acquired pneumonia (CAP) caused by M. pneumoniae or C. pneumoniae is common in children and presents as a relatively mild and self-limiting disease. CAP due to L. pneumophila is very rare in children and progresses rapidly, with fatal outcomes if not treated early. M. pneumoniae, C. pneumoniae, and L. pneumophila have no cell walls; therefore, they do not respond to β-lactam antibiotics. Accordingly, macrolides, tetracyclines, and fluoroquinolones are the treatments of choice for atypical pneumonia. Macrolides are the first-line antibiotics used in children because of their low minimum inhibitory concentrations and high safety. The incidence of pneumonia caused by macrolide-resistant M. pneumoniae that harbors point mutations has been increasing since 2000, particularly in Korea, Japan, and China. The marked increase in macrolide-resistant M. pneumoniae pneumonia (MRMP) is partly attributed to the excessive use of macrolides. MRMP does not always lead to clinical nonresponsiveness to macrolides. Furthermore, severe complicated MRMP responds to corticosteroids without requiring a change in antibiotic. This implies that the hyper-inflammatory status of the host can induce clinically refractory pneumonia regardless of mutation. Empirical macrolide therapy in children with mild to moderate CAP, particularly during periods without M. pneumoniae epidemics, may not provide additional benefits over β-lactam monotherapy and can increase the risk of MRMP.

The impact of pulse oximetry and Integrated Management of Childhood Illness (IMCI) training on antibiotic prescribing practices in rural Malawi: A mixed-methods study

BACKGROUND

The misdiagnosis of non-malarial fever in sub-Saharan Africa has contributed to the significant burden of pediatric pneumonia and the inappropriate use of antibiotics in this region. This study aims to assess the impact of 1) portable pulse oximeters and 2) Integrated Management of Childhood Illness (IMCI) continued education training on the diagnosis and treatment of non-malarial fever amongst pediatric patients being treated by the Global AIDS Interfaith Alliance (GAIA) in rural Malawi.

METHODS

This study involved a logbook review to compare treatment patterns between five GAIA mobile clinics in Mulanje, Malawi during April-June 2019. An intervention study design was employed with four study groups: 1) 2016 control, 2) 2019 control, 3) IMCI-only, and 4) IMCI and pulse oximeter. A total of 3,504 patient logbook records were included based on these inclusion criteria: age under five years, febrile, malaria-negative, and treated during the dry season. A qualitative questionnaire was distributed to the participating GAIA providers. Fisher's Exact Testing and odds ratios were calculated to compare the prescriptive practices between each study group and reported with 95% confidence intervals.

RESULTS

The pre- and post-exam scores for the providers who participated in the IMCI training showed an increase in content knowledge and understanding (p<0.001). The antibiotic prescription rates in each study group were 75% (2016 control), 85% (2019 control), 84% (IMCI only), and 42% (IMCI + pulse oximeter) (p<0.001). An increase in pneumonia diagnoses was detected for patients who received pulse oximeter evaluation with an oxygen saturation <95% (p<0.001). No significant changes in antibiotic prescribing practices were detected in the IMCI-only group (p>0.001). However, provider responses to the qualitative questionnaires indicated alternative benefits of the training including improved illness classification and increased provider confidence.

CONCLUSION

Clinics that implemented both the IMCI course and pulse oximeters exhibited a significant decrease in antibiotic prescription rates, thus highlighting the potential of this tool in combatting antibiotic overconsumption in low-resource settings. Enhanced detection of hypoxia in pediatric patients was regarded by clinicians as helpful for identifying pneumonia cases. GAIA staff appreciated the IMCI continued education training, however it did not appear to significantly impact antibiotic prescription rates and/or pneumonia diagnosis.

Influenza virus infection complicated by bacterial necrotising pneumonia: two case reports

Necrotising pneumonia (NP) is a potentially severe complication of community-acquired pneumonia characterised by necrosis of consolidated lung tissue. A 7-year-old boy and a 6-year-old boy are presented, both of whom had a complicated influenza infection which evolved into severe NP caused by Streptococcus pneumoniae. Both needed intensive care for invasive respiratory support. Despite extensive pleural involvement in both cases, only one required thoracic surgery. Case 1 also developed anaemia, hyponatraemia and hypo-albuminaemia, resulting in generalised oedema. Despite the severe morbidity, both boys made a full recovery. The diagnosis of NP should always be considered in a child with pneumonia who remains unwell despite 72 hours of appropriate antibiotics, particularly if there is evidence of pleural disease. Although S. pneumoniae is the main agent for NP, the influenza virus may be a precipitating factor.

Analysis of antibiotic usage for viral community-acquired pneumonia in adults

The rationale for the antibiotic treatment of viral community-acquired pneumonia (CAP) in adults was analyzed to develop a clinical reference standard for this condition. Clinical data from 166 patients diagnosed with viral pneumonia across 14 hospitals in Beijing from November 2010 to December 2017 were collected. The indications for medications were evaluated, and the rationale for the use of antibiotics was analyzed. A total of 163 (98.3%) patients with viral pneumonia were treated with antibiotics. A combination of C-reactive protein (CRP) and procalcitonin (PCT) was used as markers to analyze the possible indications for antibiotic use. With threshold levels set at 0.25 µg/L for PCT and 20 mg/L for CRP, the rate of unreasonable use of antibiotics was 55.2%. By contrast, at a CRP level threshold of 60 mg/L, the rate of antibiotic misuse was 77.3%. A total of 39 of the 163 (23.9%) patients did not meet the guidelines for drug selection for viral CAP in adults. The unreasonable use of antibacterial drugs for the treatment of viral CAP in adults is a serious concern. Clinicians must reduce the unnecessary use of antibiotics.

Characteristics of Hospitalized Rhinovirus-Associated Community-Acquired Pneumonia in Children, Finland, 2003-2014

Background: Rhinovirus (RV) is the most common cause of respiratory tract infections in children but, still, the clinical characteristics of RV-associated pneumonia have not been sufficiently investigated.

Methods: We identified children and adolescents younger than 18 years of age treated for community-acquired pneumonia as inpatients at the Turku University Hospital from 2003 to 2014 and analyzed for RV by PCR of a respiratory tract specimen. We collected the data from medical records and compared RV-positive children with RV-negative children.

Results: Of the study population of 313 children with pneumonia who were studied for RV, it was detected in 82 (26%). RV-positive children were younger (median age 2.6 years, interquartile range [IQR] 1.1–4.6 vs. 3.5 years, IQR 1.7–8.3, p = 0.002) and they had more often a history of preterm birth (16% vs. 5%, adjusted odds ratio 2.89, 95% confidence interval 1.21–6.92, p = 0.017) than RV-negative children. RV-positive children had a higher median white blood cell count than RV-negative children at presentation with pneumonia. The signs, symptoms, and severity of pneumonia were mostly similar in RV-positive and RV-negative children.

Conclusions: RV was frequently detected in young children hospitalized with community-acquired pneumonia. We identified premature birth as a factor associated with RV-positive pneumonia. The clinical features of pneumonia did not clearly differ between RV-positive and RV-negative children. Further studies are needed to clarify the clinical significance of detection of RV in children with pneumonia.

Effects of clinical pathway implementation on antibiotic prescriptions for pediatric community-acquired pneumonia

BACKGROUND

Italian pediatric antimicrobial prescription rates are among the highest in Europe. As a first step in an Antimicrobial Stewardship Program, we implemented a Clinical Pathway (CP) for Community Acquired Pneumonia with the aim of decreasing overall prescription of antibiotics, especially broad-spectrum.

MATERIALS AND METHODS

The CP was implemented on 10/01/2015. We collected antibiotic prescribing and outcomes data from children aged 3 months-15 years diagnosed with CAP from 10/15/2014 to 04/15/2015 (pre-intervention period) and from 10/15/2015 to 04/15/2016 (post-intervention period). We assessed antibiotic prescription differences pre- and post-CP, including rates, breadth of spectrum, and duration of therapy. We also compared length of hospital stay for inpatients and treatment failure for inpatients and outpatients. Chi-square and Fisher's exact test were used to compare categorical variables and Wilcoxon rank sum test was used to compare quantitative outcomes.

RESULTS

120 pre- and 86 post-intervention clinic visits were identified with a diagnosis of CAP. In outpatients, we observed a decrease in broad-spectrum regimens (50% pre-CP vs. 26.8% post-CP, p = 0.02), in particular macrolides, and an increase in narrow-spectrum (amoxicillin) post-CP. Post-CP children received fewer antibiotic courses (median DOT from 10 pre-CP to 8 post-CP, p<0.0001) for fewer days (median LOT from 10 pre-CP to 8 post-CP, p<0.0001) than their pre-CP counterparts. Physicians prescribed narrow-spectrum monotherapy more frequently than broad-spectrum combination therapy (DOT/LOT ratio 1.157 pre-CP vs. 1.065 post-CP). No difference in treatment failure was reported before and after implementation (2.3% pre-CP vs. 11.8% post-CP, p = 0.29). Among inpatients we also noted a decrease in broad-spectrum regimens (100% pre-CP vs. 66.7% post-CP, p = 0.02) and the introduction of narrow-spectrum regimens (0% pre-CP vs. 33.3% post-CP, p = 0.02) post-CP. Hospitalized patients received fewer antibiotic courses post-CP (median DOT from 18.5 pre-CP to 10 post-CP, p = 0.004), while there was no statistical difference in length of therapy (median LOT from 11 pre-CP to 10 post-CP, p = 0.06). Days of broad spectrum therapy were notably lower post-CP (median bsDOT from 17 pre-CP to 4.5 post-CP, p <0.0001). No difference in treatment failure was reported before and after CP implementation (16.7% pre-CP vs. 15.4% post-CP, p = 1).

CONCLUSIONS

Introduction of a CP for CAP in a Pediatric Emergency Department led to reduction of broad-spectrum antibiotic prescriptions, of combination therapy and of duration of treatment both for outpatients and inpatients.

Treatment of Community-Acquired Pneumonia: Are All Countries Treating Children in the Same Way? A Literature Review

Background

Pneumonia represents an important threat to children's health in both developed and developing countries. In the last 10 years, many national and international guidelines on the treatment of pediatric CAP have been published, in order to optimize the prescription of antibiotics and limit their cost and side effects. However, the practical implementation of these guidelines is still limited.

Main Text

We analyzed the current recommendations for the therapy of pediatric community-acquired pneumonia (CAP) that all converge on the identification of aminopenicillins and beta-lactams as the optimal treatment for CAP. We also conducted a review of the current literature on antibiotic regimens used for pediatric CAP to identify the current state of guidelines implementation in different settings. We selected 37 studies published from 2010 to 2016, including both retrospective and prospective studies, mainly cross-sectional and hospital based. The results show a global heterogeneity in the antibiotics prescription for pediatric CAP, with application of guidelines varying from 0% to more than 91% and with important differences even within the same country.

Conclusions

Our review has demonstrated that the implementation of the guidelines is still limited but also that achieving the optimal prescription is possible and can be done in both developed and developing countries.

Diagnostic Value of Nasopharyngeal Aspirates in Children with Lower Respiratory Tract Infections

Background:

The accuracy of nasopharyngeal aspirate (NPA) specimens in detecting lower respiratory pathogens remains controversial. The objective of this study was to evaluate the diagnostic accuracy of aspirates (NPAs) specimen in lower respiratory tract infections (LRTIs) in children.

Methods:

The prospective study was designed to collect the data of paired NPAs and bronchoalveolar lavage fluids from children with acute LRTIs from January 2013 to December 2015. All specimens were subjected to pathogen detection: bacterial detection by culture, Mycoplasma pneumoniae (Mp) detection by polymerase chain reaction assay and virus (influenza A and B viruses, parainfluenza virus [PIV] Types 1 and 3, respiratory syncytial virus, and adenovirus) detection by immunofluorescence assay. The diagnostic accuracy analysis of NPAs was stratified by age ≤3 years (n = 194) and >3 years (n = 294).

Results:

We collected paired specimens from 488 children. The positive rate of pathogen was 61.6%. For Streptococcus pneumoniae, NPA culture had the specificity of 89.9% and negative predictive value of 100% in age ≤3 years, the specificity of 97.2% and negative predictive value of 98.9% in age >3 years. For Mp, the positive predictive values of NPA was 77.4% in children ≤3 years, and 89.1% in children >3 years. For PIV III, NPA specimen had the specificity of 99.8% and negative predictive value of 96.5% in children ≤3 years. For adenovirus, NPA had the specificity of 97.8% and negative predictive value of 98.4% in age ≤3 years, the specificity of 98.9% and negative predictive value of 99.3% in age >3 years.

Conclusions:

NPAs are less invasive diagnostic respiratory specimens, a negative NPA result is helpful in “rule out” lower airway infection; however, a positive result does not reliably “rule in” the presence of pathogens.

Clinical features and inflammatory markers in pediatric pneumonia: a prospective study

In this prospective, observational study on previously healthy children <18 years, we aimed to study the diagnostic ability of clinical features and inflammatory markers to (i) predict pathologic chest radiography in suspected pneumonia and (ii) differentiate etiology in radiological proven pneumonia. In 394 cases of suspected pneumonia, 265 (67%) had radiographs consistent with pneumonia; 34/265 had proof of bacterial etiology. Of the cases, 86.5% had received pneumococcal conjugate vaccine. In suspected pneumonia, positive chest radiography was significantly associated with increasing C-reactive protein (CRP) values, higher age, and SpO₂ ≤92% in multivariate logistic regression, OR 1.06 (95% CI 1.03 to 1.09), OR 1.09 (95% CI 1.00 to1.18), and OR 2.71 (95% CI 1.42 to 5.18), respectively. In proven pneumonia, bacterial pneumonia was significantly differentiated from viral/atypical pneumonia by increasing CRP values and SpO₂ >92% in multivariate logistic regression, OR 1.09 (95% CI 1.05 to 1.14) and OR 0.23 (95% CI 0.06 to 0.82), respectively. Combining high CRP values (>80 mg/L) and elevated white blood cell (WBC) count provided specificity >85%, positive likelihood ratios >3, but sensitivity <46% for both radiographic proven and bacterial pneumonia.

CONCLUSION

With relatively high specificity and likelihood ratio CRP, WBC count and hypoxemia may be beneficial in ruling in a positive chest radiograph in suspected pneumonia and bacterial etiology in proven pneumonia, but with low sensitivity, the clinical utility is limited. What is Known: • Pneumonia is recommended to be a clinical diagnosis, and neither clinical features nor inflammatory markers can reliably distinguish etiology. • The etiology of pneumonia has changed after routine pneumococcal conjugate vaccine. What is New: • High CRP and WBC counts were associated with infiltrates in children with suspected pneumonia and with bacterial infection in proven pneumonia. • In the post-pneumococcal vaccination era, viral etiology is expected, and in cases of pneumonia with low CRP and WBC counts, a watch-and-wait strategy for antibiotic treatment may be applied.

Finnish guidelines for the treatment of community-acquired pneumonia and pertussis in children

Evidence-based guidelines are needed to harmonise and improve the diagnostics and treatment of children's lower respiratory tract infections. Following a professional literature search, an interdisciplinary working group evaluated and graded the available evidence and constructed guidelines for the treatment of community-acquired pneumonia and pertussis.

CONCLUSION

The clinical guidelines state that chest radiography is not needed if the child is diagnosed with pneumonia and treated at home. Complications should be considered if there is no improvement after antimicrobial therapy and a paroxysmal cough can indicate pertussis, which is life-threatening in unvaccinated infants and can lead to respiratory failure.

Etiology of community acquired pneumonia among children in India: prospective, cohort study

Background

Childhood community acquired pneumonia (CAP) is a significant problem in developing countries, and confirmation of microbial etiology is important for individual, as well as public health. However, there is paucity of data from a large cohort, examining multiple biological specimens for diverse pathogens (bacteria and viruses). The Community Acquired Pneumonia Etiology Study (CAPES) was designed to address this knowledge gap.

Methods

We enrolled children with CAP (based on WHO IMCI criteria of tachypnea with cough or breathing difficulty) over 24 consecutive months, and recorded presenting symptoms, risk factors, clinical signs, and chest radiography. We performed blood and nasopharyngeal aspirate (NPA) bacterial cultures, and serology (Mycoplasma pneumoniae, Chlamydophila pneumoniae). We also performed multiplex PCR for 25 bacterial/viral species in a subgroup representing 20% of the cohort. Children requiring endotracheal intubation underwent culture and PCR of bronchoalveolar lavage (BAL) specimens.

Findings

We enrolled 2345 children. NPA and blood cultures yielded bacteria in only 322 (13.7%) and 49 (2.1%) children respectively. In NPA, Streptococcus pneumoniae (79.1%) predominated, followed by Haemophilus influenzae (9.6%) and Staphylococcus aureus (6.8%). In blood, S. aureus (30.6%) dominated, followed by S. pneumoniae (20.4%) and Klebsiella pneumoniae (12.2%). M. pneumoniae and C. pneumoniae serology were positive in 4.3% and 1.1% respectively. Multiplex PCR in 428 NPA specimens identified organisms in 422 (98.6%); of these 352 (82.2%) had multiple organisms and only 70 (16.4%) had a single organism viz. S. pneumoniae: 35 (50%), Cytomegalovirus (CMV): 13 (18.6%), Respiratory Syncytial Virus (RSV): 9 (12.9%), other viruses: 6 (8.7%), S. aureus: 5 (7.1%), and H. influenzae: 2 (2.9%). BAL PCR (n = 30) identified single pathogens in 10 (S. pneumoniae–3, CMV–3, S. aureus–2, H. influenzae–2) and multiple pathogens in 18 children. There were 108 (4.6%) deaths. The pattern of pathogens identified did not correlate with pneumonia severity or mortality.

Conclusions

The majority of children with CAP have multiple pathogens (bacteria and viruses). S. pneumoniae and S. aureus predominate in NPA and blood respectively. CMV and RSV were the dominant respiratory viruses in NPA and BAL. The presence of multiple pathogens, especially organisms associated with nasopharyngeal carriage, precludes confirmation of a causal relationship in most cases.

[Microbiology of bronchoalveolar lavage in infants with bacterial community-acquired pneumonia with poor outcome]

BACKGROUND

Community-acquired pneumonia (CAP) is one of the most common infectious causes of morbidity and mortality in children <5 years of age. The aim of the study was to clarify the bacterial etiologic diagnosis in infants with CAP.

METHODS

A prospective, cross-sectional and descriptive study in patients 6 months to 2 years 11 months of age with CAP with poor outcome was conducted. Patients were admitted to the Pediatric Pneumology Service and underwent bronchoscopy with bronchoalveolar lavage (BAL), taking appropriate measures during the procedure to limit the risk of contamination.

RESULTS

Aerobic bacteria isolated were Moraxella sp. 23%, Streptococcus mitis 23%, Streptococcus pneumoniae 18%, Haemophilus influenzae 12%, Streptococcus oralis 12%, and Streptococcus salivarius 12%.

CONCLUSIONS

In contrast to other reports, we found Moraxella sp. to be a major bacterial pathogen, possibly because of improved detection with bronchoscopy plus BAL.

Salivary and serum analysis in children diagnosed with pneumonia

The aim of the current study was to evaluate specific markers for pneumonia by using a non-invasive assessment of inflammatory/oxidative biomarkers in saliva accompanying a routine serum analysis. No study evaluating saliva of children with pneumonia has been published previously. Salivary analysis was performed in 15 children diagnosed with lobar pneumonia and in a parallel group of 16 children matching in age and gender in whom there was no respiratory illness, and compared to the serum analysis obtained routinely in both groups of children. Salivary flow rate was lower in the patients' group as was uric acid concentration (by 60%). Increase in salivary concentrations of almost all parameters analyzed was found: Ca, P, and Mg concentrations were higher in the patients' group by 23%, 55%, and 33%, respectively, while LDH, total protein amylase and albumin concentrations were higher by 275%, 79%, and 42%, respectively. In the serum, white cell counts and neutrophils were significantly higher, and sodium level significantly lower in the patients' group. Compositional changes were in the range of 3-80% while the saliva alterations were more profound, in the range of 42-275%. The results demonstrated in the current study indicate salivary analysis as a potentially novel tool for children with pneumonia. Human salivary collection and analysis is a non-invasive tool that could provide additional information for diagnosis and follow-up of pneumonia, especially in children. This is especially beneficial for pediatric patients, as salivary collection is simple, non-invasive, and patient-friendly.

Increased production of interleukin-10 in children with Down syndrome upon ex vivo stimulation with Streptococcus pneumoniae

BACKGROUND

Children with Down syndrome (DS) have an increased susceptibility to infections, due to altered humoral and/or cellular immunity. The aim of the study was to determine the cytokine production in whole blood of children with DS upon stimulation with heat-killed Streptococcus pneumoniae and lipopolysaccharide (LPS), in comparison with their healthy siblings.

METHODS

Whole blood of 61 children with DS and 57 of their healthy siblings was stimulated with 200 ng/ml LPS and 4 × 10(7) colony-forming units/ml S. pneumoniae during 6, 24, and 48 h. Concentrations of pro- and anti-inflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, IL-12p70, and IL-10 were determined at all time points.

RESULTS

Children with DS show an increased IL-10 production upon stimulation with S. pneumoniae compared to their healthy siblings. At most time points, no significant differences were seen in cytokine production upon stimulation with LPS.

CONCLUSION

Children with DS may be prone to a severe course of pneumococcal pneumonia, because of an increased anti-inflammatory response.

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.

The impact of viral infections in children with community-acquired pneumonia

For many years viral causes of community-acquired pneumonia were often been given limited attention. The number of published studies on influenza alone increased fivefold from 2001 to 2010. Specifically several studies have underlined that the involvement of viruses in community-acquired pneumonia has been underestimated, and this underestimation has been attributed to a lack of appropriate diagnostic methods. Now, with the advent of modern molecular assays, it is well recognized that viruses account for the largest proportion of community-acquired pneumonia in preschool children in both developed and developing countries. Respiratory syncytial virus, influenza virus, adenovirus, and parainfluenza virus are the major pathogens involved, but the relative importance of additional viruses (rhinoviruses, bocavirus, human metapneumovirus) is increasing and will be better defined by future research.

Pneumococcemia in children--a retrospective study before universal pneumococcal vaccinations

AIM

To evaluate the incidence and characteristics of blood culture-positive occult pneumococcemia compared with blood culture-positive pneumococcal pneumonia in children.

METHODS

In years 2001-2010, 105 children with positive blood cultures for Streptococcus pneumoniae were identified from hospital electronic files. The patient cards were retrospectively charted for clinical and laboratory data, and 38 patients had and 67 had not pneumonia.

RESULTS

The annual incidence of pneumococcemia was, on average, 29.0/10 000 at 0-12 months, 5.3/10 000 at 13-24 months and 1.9/10 000 at 2-4 years of ages, with no increasing or decreasing trend. The incidence of bacteraemic pneumococcal pneumonia increased (p = 0.022) during the study period. The duration of fever before hospitalization (<24 h 73.9% vs. 25.0%, p = 0.022) and the duration of intravenous antibiotics, usually G-penicillin (median 72 vs. 96 h, p = 0.021) was shorter in pneumococcemia patients. On admission, blood leucocyte count was higher in pneumococcemia (mean 26.6 vs. 21.9 × 10E9/L, p = 0.012), but serum CRP was higher in pneumonia (median 160 vs. 67.4 mg/L, p < 0.001). The serotypes 6B and 14 caused 53.2% of pneumococcemia cases.

CONCLUSION

The incidence of pneumococcemia was highest in 1-2-year-old children, and typical for pneumococcemia was rapid onset of fever, high blood leucocyte count and a modestly elevated CRP on admission.

A practical approach estimating etiologic agents using real-time PCR in pediatric inpatients with community-acquired pneumonia

To evaluate pathogens in pediatric inpatients with community-acquired pneumonia (CAP), an Acute Respiratory Diseases Study Group organized by ten Japanese medical institutions devised a rapid, reliable process based on real-time PCR results in nasopharyngeal swab samples plus admission blood test results. From April 2008 to April 2009, we enrolled 903 children with CAP based on chest radiographs and clinical findings who were hospitalized within 5 days of onset. Comprehensive real-time PCR was used to detect 6 bacteria and 11 respiratory viruses. The swab specimens also were used for bacterial cultures. After initial determination of presence or absence of viral and mycoplasmal infections, significant bacterial contributions were defined by bacterial identification, clinical efficacy of antimicrobial agent, and reference to blood test results. Children were stratified by age: below 1 year, 1 year, 2-5 years, or at least 6 years old. Among patients studied, 34.4 % were diagnosed with viral infection; 21.8 %, bacterial infection; 17.5 %, viral/bacterial co-infection; 5.9 %, mycoplasmal infection; 0.3 %, mycoplasmal/bacterial co-infection; and 1.7 %, viral/mycoplasmal co-infection. The remaining 18.4 % had unknown pathogens. Purely viral infection was suggested mainly in infants younger than 1 year; mycoplasmal infection typically occurred in children at least 6 years old. Our results suggest usefulness of real-time PCR for nasopharyngeal samples together with blood tests in estimating etiologic agents in clinical settings.

[Aetiology and diagnosis of community acquired pneumonia and its complicated forms]

Community Acquired Pneumonia (CAP) is a common childhood disease, involving several paediatric subspecialties in its diagnosis and treatment. This has prompted the Spanish Society of Paediatric Pulmonology (SENP) and the Spanish Society of Paediatric Infectious Diseases (SEIP) to prepare a consensus document on the diagnosis of CAP, assessing the practical aspects by means of evidence-based medicine. It discusses the aetiology and epidemiology, with the current changes and the validity of certain laboratory tests, such as acute phase reactants, microbiological and imaging techniques, guiding the paediatricians in the real value of these tests.

Infections and immunodeficiency in Down syndrome

Down syndrome (DS) is the most common genetic disease and presents with cognitive impairment, cardiac and gastrointestinal abnormalities, in addition to other miscellaneous clinical conditions. DS individuals may have a high frequency of infections, usually of the upper respiratory tract, characterized by increased severity and prolonged course of disease, which are partially attributed to defects of the immune system. The abnormalities of the immune system associated with DS include: mild to moderate T and B cell lymphopenia, with marked decrease of naive lymphocytes, impaired mitogen-induced T cell proliferation, reduced specific antibody responses to immunizations and defects of neutrophil chemotaxis. Limited evidence of genetic abnormalities secondary to trisomy of chromosome 21 and affecting the immune system is available, such as the potential consequences of gene over-expression, most significantly SOD1 and RCAN1. Secondary immunodeficiency due to metabolic or nutritional factors in DS, particularly zinc deficiency, has been postulated. Non-immunological factors, including abnormal anatomical structures (e.g. small ear canal, tracheomalacia) and gastro-oesophageal reflux, may play a role in the increased frequency of respiratory tract infections. The molecular mechanisms leading to the immune defects observed in DS individuals and the contribution of these immunological abnormalities to the increased risk of infections require further investigation. Addressing immunological and non-immunological factors involved in the pathogenesis of infectious diseases may reduce the susceptibility to infections in DS subjects.