Necrotizing pneumonia: an emerging problem in children?

Serum IL-17A and IL-6 in paediatric Mycoplasma pneumoniae pneumonia: implications for different endotypes

Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a heterogeneous disease with a diverse spectrum of clinical phenotypes. No studies have demonstrated the relationship between underlying endotypes and clinical phenotypes as well as prognosis about this disease. Thus, we conducted a multicentre prospective longitudinal study on children hospitalized for MPP between June 2021 and March 2023, with the end of follow-up in August 2023. Blood samples were collected and processed at multiple time points. Multiplex cytokine assay was performed to characterize serum cytokine profiles and their dynamic changes after admission. Cluster analysis based on different clinical phenotypes was conducted. Among the included 196 patients, the levels of serum IL-17A and IL-6 showed remarkable variabilities. Four cytokine clusters based on the two cytokines and four clinical groups were identified. Significant elevation of IL-17A mainly correlated with diffuse bronchiolitis and lobar lesion by airway mucus hypersecretions, while that of IL-6 was largely associated with lobar lesion which later developed into lung necrosis. Besides, glucocorticoid therapy failed to inhibit IL-17A, and markedly elevated IL-17A and IL-6 levels may correlate with lower airway obliterans. Our study provides critical relationship between molecular signatures (endotypes) and clustered clinical phenotypes in paediatric patients with MPP.

Invasive Community-Acquired Methicillin-Resistant Staphylococcus aureus With Aortic Aneurysm in a 10-Year-Old Patient: A Case Report

The clinical presentation of disseminated community-acquired Methicillin-resistant Staphylococcus aureus (MRSA) in young pediatric patients without a known predisposing risk factor poses a diagnostic dilemma due to its non-specific clinical symptoms. This can lead to delayed initiation of appropriate antibiotics and surgical interventions to achieve a favorable outcome and prevent mortality. Appropriate imaging with good clinical judgment is required in the management of this infection. Outpatient surveillance for subacute and chronic complications is required for a good long-term prognosis. Few reported cases of disseminated infections with aortic aneurysm exist in the literature. We report a case of a child without predisposing risk factors managed for community-acquired MRSA sepsis, acute respiratory distress syndrome (ARDS), multiple abscesses, osteomyelitis, and necrotizing pneumonia with a post-discharge unruptured aortic aneurysm. This case emphasizes the importance of post-discharge monitoring even in patients with favorable outcomes.

A complex case of necrotizing pneumonia and parapneumonic effusion in a healthy 20-month-old child: Successful management with video-assisted thoracoscopic surgery and chest tube placement

Necrotizing pneumonia (NP) is characterized by destruction of pulmonary tissue, resulting in multiple thin-walled cavities. There are limited reports on NP and parapneumonic effusion cases in children associated with Pseudomonas aeruginosa. Currently, there is no consensus regarding the optimal timing for video-assisted thoracoscopic surgery (VATS) following failure of chest tube placement and antibiotic treatment. A healthy 20-month-old child was hospitalized with symptoms of community-acquired pneumonia, progressing to severe NP and parapneumonic effusion. Despite receiving broad-spectrum antibiotics and chest tube placement on the third day of treatment, the condition continued to deteriorate, prompting VATS intervention on the sixth day. The presence of a "split pleural sign" and extensive lung necrosis on chest computed tomography contributed to initial treatment failure. Multidrug resistance P. aeruginosa was identified through nasal trachea aspiration specimens on the eighth day of treatment, leading to an adjustment in antibiotic therapy to high-dose meropenem and amikacin. Subsequently, the patient became afebrile, showed clinical improvement, and was discharged after 35 days of treatment. Through this case, we aim to emphasize an unusual pathogenic bacteria in the context of NP and the need for standardized surgical interventions in pediatric patients with NP.

Predictive value of lactate dehydrogenase for Mycoplasma pneumoniae necrotizing pneumonia in children based on decision curve analysis and dose-response analysis

Mycoplasma pneumoniae necrotizing pneumonia (MPNP) has a long and severe disease course, which seriously threatens to jeopardize patients' lives and health. Early prediction is essential for good recovery and prognosis. In the present study, we retrospect 128 children with MPNP and 118 children with Mycoplasma pneumoniae pneumonia combined with pulmonary consolidation to explore the predictive value of lactate dehydrogenase (LDH) in children with MPNP by propensity score matching method, multiple logistic regression analysis, dose-response analysis and decision curve analysis. The WBC count, PLT count and percentage of neutrophils were significantly higher in necrosis group than consolidation group. The serum CRP, PCT, ESR, D-D, FIB, ALT, LDH, IgG and IgM were significantly higher in necrosis group. Compared to consolidation group, necrosis group is more severe in chest pain and dyspnea. Multivariate logistic regression analysis showed that duration of LDH levels, high fever, D-dimer, and fibrinogen were independent predictive factors for the incidence of MPNP. Restricted cubic spline analysis showed that a non-linear dose-response relationship between the continuous changes of LDH level and the incidence of MPNP. Decision curve analysis revealed that LDH had an important clinical value in predicting MPNP. This study provides a potential serologic indicator for early diagnosis of MPNP.

Necrotizing pneumonia in children: Report of 25 cases between 2008 and 2018 at a French tertiary care center

BACKGROUND

Necrotizing pneumonia (NP) is a serious and rare disease in children. Pediatric data on NP are limited and the impact of the 13-valent pneumococcal conjugate vaccine has been very poorly evaluated.

PATIENTS AND METHODS

We conducted a retrospective study at Toulouse University Hospital between 2008 and 2018. Children who presented with thin-walled cavities in the areas of parenchymal consolidation on imaging were included in the study.

RESULTS

The incidence of NP did not decrease during this period. Bacterial identification occurred in 56% of cases (14/25) and included six cases of Streptococcus pneumoniae, five of Staphylococcus aureus, two of Streptococcus pyogenes, and one of Streptococcus viridans. Streptococcus pneumoniae NP are more frequently associated with empyema/parapneumonic effusion compared to S. aureus NP (p = 0.02). Patients with S. pyogenes NP more often required volume expansion than did S. pneumoniae cases (p = 0.03). When comparing children born before and after implementation of the 13-valent pneumococcal conjugate vaccine, we identified a relative modification of the bacterial epidemiology, with an increase in the proportion of S. pyogenes NP and S. aureus NP and a decrease in the proportion of NP caused by S. pneumoniae.

CONCLUSION

Future studies are needed to assess the epidemiology of NP in children. Continued surveillance of identified pneumococcal serotypes is essential to document epidemiological changes in the coming years.

Clinical Characteristics of Lung Consolidation with Mycoplasma pneumoniae Pneumonia and Risk Factors for Mycoplasma pneumoniae Necrotizing Pneumonia in Children

INTRODUCTION

Mycoplasma pneumoniae necrotizing pneumonia (MPNP) is an uncommon but increasingly recognized severe complication of pneumonia, and the delayed diagnosis and treatment are prone to pulmonary sequelae. The aim of this study is to explore independent risk factors for MPNP in children with lung consolidation.

METHODS

A retrospective observational study was conducted on 118 children with MPNP (MPNP group) and 184 children with lung consolidation of Mycoplasma pneumoniae pneumonia (MPP) (control group) admitted to Children's Hospital Affiliated to Zhengzhou University from June 2018 to August 2023. Clinical manifestations and laboratory data were analyzed and the independent risk factors for MPNP in children were analyzed by multivariate logistic regression.

RESULTS

The age of onset, hospitalization days, fever days, proportion of dyspnea, chest pain, complications, and need for fiberoptic bronchoscopic alveolar lavage (FBAL) were higher than those in the control group, and the difference was statistically significant (P < 0.05). The levels of white blood cells (WBC), platelets, neutrophil percentage (N%), neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP), fibrinogen (Fbg), D-dimer (D-D), erythrocyte sedimentation rate (ESR), alanine transaminase (ALT), γ-glutamyl transpeptidase (γ-GGT), globulin, lactate dehydrogenase (LDH), α-hydroxybutyrate dehydrogenase (α-HBDH), urea, immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin A (IgA), complement component 3, antistreptolysin O (ASO), serum ferritin, and interleukin-6 (IL-6) in the MPNP group were higher than those in the control group. Red blood cell (RBC), lymphocyte percentage (L%), activated partial thromboplastin time (APTT), alkaline phosphatase (ALP), total protein, albumin, albumin-to-globulin ratio (AGR), creatine kinase (CK), uric acid, natrium, chlorine, calcium, and complement C4 in the MPNP group were lower than those in the control group, and the difference was statistically significant (P < 0.05). The results of multivariate logistic regression analysis showed that age ≥ 83.50 months, fever days ≥ 10.50, ALT ≥ 15.25 U/l, IgM ≥ 1.46 g/l, complement C3 ≥ 1.47 g/l, Fbg ≥ 3.93 g/l, dyspnea and needing FBAL were independent risk factors for MPNP in children.

CONCLUSIONS

Age, fever days, ALT, IgM, complement C3, Fbg, dyspnea, and needing FBAL were independent risk factors for MPNP in children. For children suspected of MPNP, pediatricians should pay close attention to the above indicators, strive for early diagnosis and treatment, and improve prognosis.

Changes in coagulation markers in children with Mycoplasma pneumoniae pneumonia and their predictive value for Mycoplasma severity

BACKGROUND

This study investigates the correlation between coagulation levels and the severity of Mycoplasma pneumoniae pneumonia (MPP) in children. In addition, the study analyses the predictive value of coagulation abnormalities in MPP combined with necrotising pneumonia (NP).

METHODS

A total of 170 children with MPP who underwent treatment between June 2021 and February 2022 were selected for this study. The study population was divided into groups according to the severity of the disease to compare differences in the incidence of coagulation abnormalities between the groups. The participants were also divided into groups according to imaging manifestations to compare the differences in coagulation function among the different groups. All data information was processed for statistical analysis using SPSS Statistics 25.0 and GraphPad Prism 7.0 statistical analysis software.

RESULTS

The incidence of coagulation abnormalities in the children in the severe MPP (SMPP) group was significantly higher than that in the normal MPP (NMPP) group (P < 0.05). The multi-factor logistic regression analysis revealed that the D-dimer level is an independent risk factor for the development of NP in SMPP (P < 0.05). The receiver operating characteristic curve analysis revealed statistically significant differences (P < 0.05) in D-dimer, fibrinogen degeneration products (FDP), neutrophils, lactate dehydrogenase and serum ferritin for predicting SMPP combined with NP. Bronchoscopic manifestations of coagulation indicators (D-dimer and FDP levels) were significantly higher in the mucus plug group than in the non-mucus plug group, while the activated partial thromboplastin time levels were lower in the former than in the latter (P < 0.05).

CONCLUSION

The degree of elevated D-dimer and FDP levels was positively correlated with the severity of MPP, with elevated serum D-dimer levels (> 3.705 mg/L) serving as an independent predictor of MPP combined with NP in children.

[Construction of a predictive model for performing bronchoalveolar lavage in children with Mycoplasma pneumoniae pneumonia and pulmonary consolidation]

OBJECTIVES

To investigate the risk factors for performing bronchoalveolar lavage (BAL) in children with Mycoplasma pneumoniae pneumonia (MPP) and pulmonary consolidation, and to construct a predictive model for performing BAL in these children.

METHODS

A retrospective analysis was performed for the clinical data of 202 children with MPP who were hospitalized in the Department of Pediatrics, Changzhou No. 2 People's Hospital Affiliated to Nanjing Medical University, from August 2019 to September 2022. According to whether BAL was performed, they were divided into BAL group with 100 children and non-BAL group with 102 children. A multivariate logistic regression analysis was used to identify the risk factors for performing BAL in MPP children with pulmonary consolidation. Rstudio software (R4.2.3) was used to establish a predictive model for performing BAL, and the receiver operator characteristic (ROC) curve, C-index, and calibration curve were used to assess the predictive performance of the model.

RESULTS

The multivariate logistic regression analysis demonstrated that the fever duration, C-reactive protein levels, D-dimer levels, and presence of pleural effusion were risk factors for performing BAL in MPP children with pulmonary consolidation (P<0.05). A nomogram predictive model was established based on the results of the multivariate logistic regression analysis. In the training set, this model had an area under the ROC curve of 0.915 (95%CI: 0.827-0.938), with a sensitivity of 0.826 and a specificity of 0.875, while in the validation set, it had an area under the ROC curve of 0.983 (95%CI: 0.912-0.996), with a sensitivity of 0.879 and a specificity of 1.000. The Bootstrap-corrected C-index was 0.952 (95%CI: 0.901-0.986), and the calibration curve demonstrated good consistency between the predicted probability of the model and the actual probability of occurrence.

CONCLUSIONS

The predictive model established in this study can be used to assess the likelihood of performing BAL in MPP children with pulmonary consolidation, based on factors such as fever duration, C-reactive protein levels, D-dimer levels, and the presence of pleural effusion. Additionally, the model demonstrates good predictive performance.

Complex Regulation of Gamma-Hemolysin Expression Impacts Staphylococcus aureus Virulence

Staphylococcus aureus gamma-hemolysin CB (HlgCB) is a core-genome-encoded pore-forming toxin that targets the C5a receptor, similar to the phage-encoded Panton-Valentine leucocidin (PVL). Absolute quantification by mass spectrometry of HlgCB in 39 community-acquired pneumonia (CAP) isolates showed considerable variations in the HlgC and HlgB yields between isolates. Moreover, although HlgC and HlgB are encoded on a single operon, their levels were dissociated in 10% of the clinical strains studied. To decipher the molecular basis for the variation in hlgCB expression and protein production among strains, different regulation levels were analyzed in representative clinical isolates and reference strains. Both the HlgCB level and the HlgC/HlgB ratio were found to depend on hlgC promoter activity and mRNA processing and translation. Strikingly, only one single nucleotide polymorphism (SNP) in the 5' untranslated region (UTR) of hlgCB mRNA strongly impaired hlgC translation in the USA300 strain, leading to a strong decrease in the level of HlgC but not in HlgB. Finally, we found that high levels of HlgCB synthesis led to mortality in a rabbit model of pneumonia, correlated with the implication of the role of HlgCB in severe S. aureus CAP. Taken together, this work illustrates the complexity of virulence factor expression in clinical strains and demonstrates a butterfly effect where subtle genomic variations have a major impact on phenotype and virulence. IMPORTANCE S. aureus virulence in pneumonia results in its ability to produce several virulence factors, including the leucocidin PVL. Here, we demonstrate that HlgCB, another leucocidin, which targets the same receptors as PVL, highly contributes to S. aureus virulence in pvl-negative strains. In addition, considerable variations in HlgCB quantities are observed among clinical isolates from patients with CAP. Biomolecular analyses have revealed that a few SNPs in the promoter sequences and only one SNP in the 5' UTR of hlgCB mRNA induce the differential expression of hlgCB, drastically impacting hlgC mRNA translation. This work illustrates the subtlety of regulatory mechanisms in bacteria, especially the sometimes major effects on phenotypes of single nucleotide variation in noncoding regions.

A pediatric case series of invasive pneumococcal disease caused by S.Pneumonia serotype-19A despite full dose vaccination

Streptococcus pneumoniae is the leading cause of community-acquired pneumonia and bacterial meningitis in children. Although pneumococcal conjugate vaccines (PCVs) are commonly available, invasive pneumococcal disease (IPD) still remains a life-threatening complication. Serotype 19A has high invasive potential and is capable of causing extensive and destructive lung disease. This strain has greater invasive potential, may have a growth advantage over other pneumococcal serotypes in normally sterile sites, and is often resistant to multiple antibiotics. Although being a component of PCV13 vaccine, serotype 19A may still be seen in fully vaccinated children and can cause invasive disease. Herein, we present four cases of IPD caused by S. pneumoniae serotype 19A who received the full regimen of PCV13 vaccination.

Clinical Characteristics of Necrotizing Pneumonia Caused by Different Pathogens

Objective

To explore the clinical characteristics of necrotizing pneumonia (NP) caused by different pathogens.

Methods

A total of 282 children with NP admitted to Kunming Children's Hospital from January 2014 to November 2022 were enrolled. The clinical data of all children was collected. According to the different pathogens causing NP, the children were divided into three groups: the Mycoplasma pneumoniae necrotizing pneumonia (MPNP) group, the bacterial necrotizing pneumonia (BNP) group, and necrotizing pneumonia with no pathogen detected (NNP) group. The basic information, symptoms, signs, laboratory tests, radiological features, treatment, and prognosis of the three groups were compared.

Results

Among the 282 cases of NP, there were 62 (22.0%) cases of MPNP, 98 (34.75%) cases of BNP, and 142 (50.35%) cases of NNP. The most common bacteria causing NP were Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Acinetobacter baumannii, respectively. Most clinical features of the three groups were statistically significant. The area under the concentration curve of white blood cell, C-reactive protein, albumin, neutrophil percentage, and fibrinogen in differentiating MPNP from BNP were 0.743 (0.638-0.849), 0.797 (0.711-0.883), 0.766 (0.671-0.861), 0.616 (0.509-0.724), and 0.634 (0.523-0.744), respectively. The decision curve showed that white blood cells, albumin, and C-reactive protein had good clinical application in differentiating MPNP from BNP. All patients were improved and discharged without death.

Conclusion

Bacteria are the most common cause of NP, and the most common bacteria are Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenzae. NP with no pathogen detected accounted for a large proportion. white blood, C-reactive protein, and albumin can identify the pathogens of NP. Patients with BNP were more severe, had a longer hospital stay, and were more likely to undergo closed drainage and surgery.

Necrotizing Pneumonia Secondary to Pulmonary Blastomycosis: A Case Report

Necrotizing pneumonia is a rare but potentially life-threatening complication of pulmonary blastomycosis, a fungal infection caused by inhaling spores of the fungus Blastomyces dermatitidis. This case report describes a 56-year-old male who presented with worsening malaise, subjective fevers and chills, night sweats, and a productive cough. Further evaluation revealed a right upper lobe necrotizing pneumonia secondary to pulmonary blastomycosis.

Necrotizing Pneumonia in Children: Early Recognition and Management

Necrotizing pneumonia (NP) is an uncommon complicated pneumonia with an increasing incidence. Early recognition and timely management can bring excellent outcomes. The diagnosis of NP depends on chest computed tomography, which has radiation damage and may miss the optimal treatment time. The present review aimed to elaborate on the reported predictors for NP. The possible pathogenesis of Streptococcus pneumoniae, Staphylococcus aureus, Mycoplasma pneumoniae and coinfection, clinical manifestations and management were also discussed. Although there is still a long way for these predictors to be used in clinical, it is necessary to investigate early predictors for NP in children.

Oxidative Reactions Catalyzed by Hydrogen Peroxide Produced by Streptococcus pneumoniae and Other Streptococci Cause the Release and Degradation of Heme from Hemoglobin

Streptococcus pneumoniae (Spn) strains cause pneumonia that kills millions every year worldwide. Spn produces Ply, a hemolysin that lyses erythrocytes releasing hemoglobin, and also produces the pro-oxidant hydrogen peroxide (Spn-H2O2) during growth. The hallmark of the pathophysiology of hemolytic diseases is the oxidation of hemoglobin, but oxidative reactions catalyzed by Spn-H2O2 have been poorly studied. We characterized the oxidation of hemoglobin by Spn-H2O2. We prepared a series of single-mutant (ΔspxB or ΔlctO), double-mutant (ΔspxB ΔlctO), and complemented strains in TIGR4, D39, and EF3030. We then utilized an in vitro model with oxyhemoglobin to demonstrate that oxyhemoglobin was oxidized rapidly, within 30 min of incubation, by Spn-H2O2 to methemoglobin and that the main source of Spn-H2O2 was pyruvate oxidase (SpxB). Moreover, extended incubation caused the release and the degradation of heme. We then assessed oxidation of hemoglobin and heme degradation by other bacterial inhabitants of the respiratory tract. All hydrogen peroxide-producing streptococci tested caused the oxidation of hemoglobin and heme degradation, whereas bacterial species that produce <1 μM H2O2 neither oxidized hemoglobin nor degraded heme. An ex vivo bacteremia model confirmed that oxidation of hemoglobin and heme degradation occurred concurrently with hemoglobin that was released from erythrocytes by Ply. Finally, gene expression studies demonstrated that heme, but not red blood cells or hemoglobin, induced upregulated transcription of the spxB gene. Oxidation of hemoglobin may be important for pathogenesis and for the symbiosis of hydrogen peroxide-producing bacteria with other species by providing nutrients such as iron.

Early predictors of lung necrosis severity in children with community-acquired necrotizing pneumonia

OBJECTIVE

To analyze baseline clinical and laboratory characteristics and explore the possible predictors of lung necrosis severity in children with community-acquired necrotizing pneumonia (NP).

METHODOLOGY

This retrospective observational study was performed in a tertiary referral center. A total of 104 patients aged <15 years with community-acquired pneumonia and radiologically confirmed NP by computed tomography (CT) were included. Patients were classified into the mild, moderate, or massive necrosis groups.

RESULTS

Among them, 29, 41, and 34 patients had mild, moderate, and massive necrosis, respectively. Moreover, 34.6% of the patients were admitted to pediatric intensive care unit. Massive necrosis was more likely to occur during winter (p < 0.05) and was associated with more severe clinical outcomes, such as longer duration of fever, longer hospitalization, increased mortality, and a higher risk of subsequent surgical intervention (p < 0.05). Multivariate analysis demonstrated that the following were independent risk factors for massive necrosis in this study: C-reactive protein (CRP) (p = 0.036), serum albumin (p = 0.009), and immunoglobulin M (IgM) (p = 0.022). Receiver operating characteristic analysis showed that when the cut-off value for CRP, serum albumin, and IgM were set at 122 mg/L, 30.8 g/L, and 95.7 mg/dl, respectively, they showed good diagnostic performance for differentiating patients with massive necrosis from all patients with NP.

CONCLUSION

NP is a potentially severe complication of pediatric community-acquired pneumonia. Different severities of lung necrosis can lead to different clinical outcomes. CRP, serum albumin, and IgM levels are independent predictors of the degree of lung necrosis.

Surfactant for a Patient with Refractory Pyopneumothorax and Acute Respiratory Distress Syndrome Due to Pneumococcal Necrotizing Pneumonia Complicated by a Bronchopleural Fistula

Background: Necrotizing pneumonia rarely occurs in children, but when it does it can be complicated by bronchopleural fistula, empyema, pneumothorax, sepsis, and acute respiratory distress syndrome (ARDS). Antimicrobial therapy is the cornerstone of its management; however, surgery is necessary in some cases. Ideally, surgical interventions are kept to a minimum, but this is not always possible if there is a mass effect from air and fluid in the pleural space, pulmonary necrosis leading to massive hemoptysis, uncontrolled sepsis, or difficulties with assisted ventilation. Case Presentation: Herein we present a patient with refractory pyopneumothorax and ARDS due to pneumococcal necrotizing pneumonia complicated by a bronchopleural fistula. The patient's clinical condition deteriorated despite antibiotics, surgical drainage, and assisted ventilation. Owing to pneumothorax with a high percentage of air leakage, bilateral diffuse collapse of the lungs, and insufficient oxygenation, surgical treatment was considered, but because of the patient's lack of tolerance for surgery due to hemodynamic reasons and the complications associated with surgery, medical treatment was determined to be more appropriate. Surfactant treatment was administered to the patient, resulting in significant clinical improvement. Conclusion: To the best of our knowledge, this is the first report of the use of surfactant to treat ARDS due to necrotizing pneumonia. Based on the presented case, we think surfactant can be considered as a salvage treatment for such patients.

Necrotizing pneumonia requiring prolonged extracorporeal membrane oxygenation: Pushing the boundaries in pediatric ECMO

Extracorporeal membrane oxygenation (ECMO) is a life‐saving rescue therapy used in acute respiratory failure refractory to invasive mechanical ventilation. Recent studies on positive outcomes of extended ECMO therapy are promising. We describe a case of a 2‐year 8‐month‐old female child with necrotizing pneumonia secondary to Streptococcus pneumoniae, Influenza A, and Mycoplasma pneumoniae, who survived with intact neurological function and no long‐term adverse outcomes after a prolonged ECMO run of 86 days. To the best of our knowledge, this is one of the longer durations of ECMO with transplant‐free survival in a pediatric patient requiring respiratory support with good recovery and a good functional outcome. Allowing time for native lung recovery is pivotal for optimal recovery, despite significant lung injury due to the underlying disease process. With evolving ECMO experience, clinicians may need to re‐consider the conventional maximum duration of ECMO in children with severe respiratory failure on a case‐by‐case basis.

[Analysis of clinical features and risk factors of necrotizing pneumonia in children]

OBJECTIVE

To investigate the clinical characteristics and risk factor analysis of necrotizing pneumonia in children.

METHODS

A retrospective study was used to analyze the case data of 218 children with severe pneumonia hospitalized in the Department of Respiratory Medicine, Children's Hospital of Capital Institute of Pediatrics from January 2016 to January 2020, and they were divided into 96 cases in the necrotizing pneumonia group (NP group) and 122 cases in the non-necrotizing pneumonia group (NNP group) according to whether necrosis of the lung occurred. The differences in clinical characteristics (malnutrition, fever duration, hospitalization time, imaging performance, treatment and regression follow-up), laboratory tests [leukocytes, neutrophil ratio, platelet (PLT), C-reactive protein (CRP), procalcitonin (PCT), D-dimer, and lactate dehydrogenase (LDH)] and bronchoscopic performance between the two groups were compared, and Logistic regression analysis of clinical risk factors associated with necrotizing pneumonia was performed to further determine the maximum diagnostic value of each index by subject operating characteristic curve (ROC). The critical value of each index was further determined by the ROC.

RESULTS

The differences in age, gender, pathogenic classification, and bronchoscopic presentation between the two groups of children were not statistically significant (P>0.05); whereas the imaging uptake time of the children in the NP group was higher than that in the NNP group (P < 0.05). The differences in malnutrition, fever duration, length of stay, white blood cell count, neutrophil ratio, CRP, PCT, and D-dimer were statistically significant between the two groups (P < 0.05). The imaging uptake time was lower in children under 6 years of age than in those over 6 years of age, and the imaging uptake time for bronchoalveolar lavage within 10 d of disease duration was lower than that for those over 10 d; the imaging uptake time was significantly longer in the mixed infection group than that in the single pathogen infection group. Logistic regression analysis of the two groups revealed that the duration of fever, hospital stay, CRP, PCT, and D-dimer were risk factors for secondary pulmonary necrosis (P < 0.001, P < 0.001, P < 0.001, P=0.013, P=0.001, respectively). The ROC curves for fever duration, CRP, PCT, and D-dimer were plotted and found to have diagnostic value for predicting the occurrence of pulmonary necrosis when fever duration >11.5 d, CRP >48.35 mg/L, and D-dimer > 4.25 mg/L [area under ROC curve (AUC)=0.909, 0.836, and 0.747, all P < 0.001].

CONCLUSION

Children with necrotizing pneumonia have a longer heat course and hospital stay, and the imaging uptake time of mixed pathogenic infections is significantly longer than that of single pathogenic infections. Children with necrotizing pneumonia under 6 years of age have more advantageous efficacy of electronic bronchoscopic alveolar lavage within 10 d of disease duration compared with children in the group over 6 years of age and children in the group with disease duration >10 d. Inflammatory indexes CRP, PCT, and D-dimer are significantly higher. The heat course, CRP, PCT, and D-dimer are risk factors for secondary lung necrosis in severe pneumonia. Heat course >11.5 d, CRP >48.35 mg/L, and D-dimer >4.25 mg/L have high predictive value for the diagnosis of necrotizing pneumonia.

[Analysis of clinical features and risk factors of necrotizing pneumonia in children]

OBJECTIVE

To investigate the clinical characteristics and risk factor analysis of necrotizing pneumonia in children.

METHODS

A retrospective study was used to analyze the case data of 218 children with severe pneumonia hospitalized in the Department of Respiratory Medicine, Children's Hospital of Capital Institute of Pediatrics from January 2016 to January 2020, and they were divided into 96 cases in the necrotizing pneumonia group (NP group) and 122 cases in the non-necrotizing pneumonia group (NNP group) according to whether necrosis of the lung occurred. The differences in clinical characteristics (malnutrition, fever duration, hospitalization time, imaging performance, treatment and regression follow-up), laboratory tests [leukocytes, neutrophil ratio, platelet (PLT), C-reactive protein (CRP), procalcitonin (PCT), D-dimer, and lactate dehydrogenase (LDH)] and bronchoscopic performance between the two groups were compared, and Logistic regression analysis of clinical risk factors associated with necrotizing pneumonia was performed to further determine the maximum diagnostic value of each index by subject operating characteristic curve (ROC). The critical value of each index was further determined by the ROC.

RESULTS

The differences in age, gender, pathogenic classification, and bronchoscopic presentation between the two groups of children were not statistically significant (P>0.05); whereas the imaging uptake time of the children in the NP group was higher than that in the NNP group (P < 0.05). The differences in malnutrition, fever duration, length of stay, white blood cell count, neutrophil ratio, CRP, PCT, and D-dimer were statistically significant between the two groups (P < 0.05). The imaging uptake time was lower in children under 6 years of age than in those over 6 years of age, and the imaging uptake time for bronchoalveolar lavage within 10 d of disease duration was lower than that for those over 10 d; the imaging uptake time was significantly longer in the mixed infection group than that in the single pathogen infection group. Logistic regression analysis of the two groups revealed that the duration of fever, hospital stay, CRP, PCT, and D-dimer were risk factors for secondary pulmonary necrosis (P < 0.001, P < 0.001, P < 0.001, P=0.013, P=0.001, respectively). The ROC curves for fever duration, CRP, PCT, and D-dimer were plotted and found to have diagnostic value for predicting the occurrence of pulmonary necrosis when fever duration >11.5 d, CRP >48.35 mg/L, and D-dimer > 4.25 mg/L [area under ROC curve (AUC)=0.909, 0.836, and 0.747, all P < 0.001].

CONCLUSION

Children with necrotizing pneumonia have a longer heat course and hospital stay, and the imaging uptake time of mixed pathogenic infections is significantly longer than that of single pathogenic infections. Children with necrotizing pneumonia under 6 years of age have more advantageous efficacy of electronic bronchoscopic alveolar lavage within 10 d of disease duration compared with children in the group over 6 years of age and children in the group with disease duration >10 d. Inflammatory indexes CRP, PCT, and D-dimer are significantly higher. The heat course, CRP, PCT, and D-dimer are risk factors for secondary lung necrosis in severe pneumonia. Heat course >11.5 d, CRP >48.35 mg/L, and D-dimer >4.25 mg/L have high predictive value for the diagnosis of necrotizing pneumonia.

Entzündliche und infektiöse Erkrankungen der Lunge und Pleura bei Kindern und Jugendlichen

Entzündliche Erkrankungen der Lunge und Pleura bei Kindern und Jugendlichen umfassen ein weites Spektrum von der komplizierten Pneumonie, der Tuberkulose, Mykosen bis hin zur Echinokokkose. Die Häufigkeit hängt stark von der geografischen Herkunft ab. Diese Übersichtsarbeit gibt einen Überblick von der Diagnostik bis hin zur chirurgischen Therapie dieser Erkrankungen beim pädiatrischen Kollektiv.

Lung Resection in Children with Necrotizing Pneumonia: Outcome and Follow-up

INTRODUCTION

 The number of patients with necrotizing pneumonia has increased in recent years. The aim of this study is to review the incidence, management, and outcome of pediatric necrotizing pneumonia requiring surgical therapy and to prove that lung resection results in favorable development of patients. We hypothesize that overall lung function in children after lung resection does not differ from that of the healthy population.

MATERIALS AND METHODS

 A retrospective tertiary referral center study with a prospective follow-up spirometric study of patients with necrotizing pneumonia managed between January 2010 and December 2019 was performed.

RESULTS

 The study cohort consisted of 1,295 patients admitted to the pediatric department for community-acquired pneumonia; 47 patients developed necrotizing pneumonia, 36 of whom underwent parenchymal lung resection. A 5-year rise in the occurrence of necrotizing pneumonia requiring resection was 77%, with a significant increase in the last 3 years (p < 0.05). The median age at the time of surgery was 32.5 (interquartile range [IQR]: 32.25) months. Streptococcus pneumoniae was the most prevalent pathogen (83%), although 53.3% of these patients were vaccinated against the agent. In 67% of patients, preresection procedures were performed: drainage of pneumothorax (17%), drainage of empyema (46%), drainage of empyema with use of alteplase (25%), and thoracoscopic decortication (12%). Surgical procedures included lobectomy (72.2%), wedge resection (13.9%), bilobectomy (8.3%), and pneumonectomy (5.6%). The postoperative complication was bronchopleural fistula in three patients. There were two (5.5%) postoperative deaths due to multiple organ failure. The follow-up spirometry was performed 43.3 (median, IQR 23.8-66.7) months after surgical intervention. Normal lung function was detected in 35 (64.8%) patients, restrictive pattern in 6 (11.1%) patients, obstructive pattern in 11 (20.4%) patients, and combined in 2 (3.7%) patients.

CONCLUSION

 The number of patients with necrotizing pneumonia requiring resection has increased significantly in the last 3 years (p < 0.05). Aggressive surgical treatment results in significant clinical improvement in most cases and favorable lung function outcome. Long-term follow-up showed normal spirometry in 64.8% of cases.

Streptococcus anginosus group infections in hospitalised children and young people

AIM

The Streptococcus anginosus group (SAG) comprises three bacterial species colonising the mouth and gastrointestinal and genitourinary tracts and capable of serious pyogenic infections. Although well-described in adults, studies in children are limited. Here, we characterise paediatric SAG infections from a single Australian centre.

METHODS

Hospitalised patients aged ≤18 years with positive SAG cultures from January 2009 to December 2019 were identified from Pathology Queensland's Gold Coast Laboratory database and their medical records were reviewed.

RESULTS

Two-hundred children (62% male), median age 12 years (interquartile range 6-16), with positive SAG cultures were identified. Overall, 90% received intravenous antibiotics, 89% underwent surgical drainage, 23% were readmitted and 15% required additional surgery. The most common sites were the abdomen (39%), soft tissues (36%) and head and neck regions (21%). Since 2011, Pathology Queensland reported SAG at the species level (n = 133). Of these, S. anginosus was the most prevalent (39%), then S. constellatus (34%) and S. intermedius (27%). Compared with the other two species, S. intermedius was most commonly associated with head and neck infections (relative risk (RR) = 2.2, 95% confidence interval (CI) 1.4-3.5), while S. constellatus (RR = 1.7, 95% CI 1.2-2.4) and S. anginosus (RR = 1.5, 95% CI 1.0-2.0) were each associated with a higher risk of intra-abdominal infection than S. intermedius. Since February 2015, the number of children admitted with SAG-associated intra-abdominal infection per 1000 hospitalisations increased by 29% annually compared with an annual decline of 8% in previous years.

CONCLUSIONS

SAG infections occur at various anatomical sites. Despite antibiotics and surgical management, almost one-quarter are re-hospitalised for further treatment.

CT findings predicting lung resection in children with complicated community-acquired pneumonia

PURPOSE

To investigate computed tomography (CT) features which predict lung resection in children with complicated community-acquired pneumonia.

METHODS

A retrospective study of CT findings of patients with complicated pneumonia treated between January 2010 and December 2019. Fisher's exact test and ROC curves were used for statistical analysis.

RESULTS

The study cohort consisted of 84 patients who underwent chest CT for complicated pneumonia. Lung resection was performed in 36 patients, 3 patients were treated by lung decortication, 45 patients were cured conservatively. Seven CT features were found statistically significant among the patients who underwent lung resection. 80.5% of patients from the resection group had two or more of these features on the initial CT scan, 64% had three or more. According to ROC analysis, simultaneous occurrence of multiple cavities equal to or greater than 3 cm and lung abscess predicted a pulmonary resection.

CONCLUSION

The combination of CT features which clearly predict lung resection are the simultaneous occurrence of multiple cavities ≥ 3 cm and lung abscess. The most common triple combination of CT signs in the resected group of patients were multiple cavities ≥ 3 cm, consolidation of lung tissue and pleural effusion < 3 cm.

Treatment of the most common respiratory infections in children

Acute respiratory infections are the most common group of infective diseases in the pediatric population. Although the improvement of health care and vaccination program has led to a significant reduction in the incidence of certain respiratory infections, the combination of a high prevalence in vulnerable pediatric categories and uncritical prescription of antibiotics, due to the inability to adequately distinguish between viruses and bacterial etiology, still represents a significant challenge for the public health system. In order to promote rational antibiotic therapy with an overall improvement of both diagnostic and therapeutic principles, acute respiratory diseases have been the subject of consideration in numerous publications and national guidelines. Nonspecific clinical manifestations with pathogen heterogeneity and both anatomical and physiological characteristics of the child's respiratory system during growth and development have created the need for individualized therapy. Since the guidelines emphasize the undoubtful and crucial benefits of symptomatic therapy (e.g. analgesics in acute otitis media, supplemental oxygen in lower respiratory tract infections with hypoxemia), the use of antibiotics and corticosteroids is indicated in selected cases with a severe clinical picture. The choice of antibiotic depends on the clinical condition, presumed causative agent, and local epidemiologic circumstances. Respiratory support (oxygen therapy and/or artificial ventilation) is reserved for inpatient treatment of cases with a particularly severe clinical picture and associated complications.

Necrotizing pneumonia in children: Chest computed tomography vs. lung ultrasound

BACKGROUND

The utilization of contrast-enhanced computed tomography (CT) of the chest for the diagnosis of necrotizing pneumonia (NP), a complication of community-acquired pneumonia, is controversial because of the inherent ionizing radiation involved. Over the past few years, the growing availability of bedside Lung Ultrasound (LUS) devices has led to increased use of this nonionizing imaging method for diagnosing thoracic pathology, including pneumonia.

OBJECTIVE

The objectives of this study were as follows: first, to compare the performance of LUS vs. CT in the identification of certain radiological signs of NP, and second, to determine whether LUS could replace CT in the diagnosis of NP.

MATERIALS AND METHODS

We compared retrospectively the CT and LUS images of 41 patients between 2005 and 2018 in whom at least one contrast-injected chest CT scan and one LUS had been undertaken fewer than 7 days apart.

RESULTS

Pleural effusions were demonstrated almost systematically (100% on CT vs. 95.8% on LUS). Visualization of septations in pleural effusions was clearly superior on LUS (20.4% on CT vs 62.5% on LUS). Concerning the detection of necrosis, we observed a strong correlation between LUS and the gold-standard CT (95.8% on LUS vs. 93.7% on CT). Parenchymal cavities were more easily detected on CT than on LUS (79.1 vs. 35.4%).

CONCLUSION

LUS has shown to be as effective as CT in the diagnosis of NP. The use of CT in patients with NP could be limited to the detection of complications such as bronchopleural fistulae in unfavorably evolving diseases.

Risk factors for complicated community-acquired pneumonia in children

BACKGROUND

Community-acquired pneumonia (CAP) in children continues to be one of the prominent causes of pediatric morbidity and mortality worldwide. By determining the risk factors associated with the development of complicated CAP (CCAP), new approaches for early diagnosis and effective treatment can be identified.

METHODS

This retrospective cohort study enrolled patients with CAP and CCAP who visited the pediatric ward of the study hospital between January 1, 2017 and December 31, 2017. For patients with CCAP, data regarding medical procedures performed, surgical intervention, and hospitalization duration were collected.

RESULTS

A total of 111 patients, 93 (83.7%) with CAP and 18 (16.3%) with CCAP, aged between 3 months and 18 years were hospitalized because of severe pneumonia. The mean age of the patients was 3.6 ± 1.2 years and 60 (54%) of them were female. The mean age of patients with CCAP was higher than that of patients with CAP (4.2 ± 3.3 vs. 2.8 ± 2.1 years respectively); however, the difference was not significant (p = 0.012). Patients with CCAP exhibited a significantly higher C-reactive protein level than those with CAP (10.06 ± 7.55 vs. 4.43 ± 3.37 g/L respectively; p = 0.007). Hypoxia upon admission was noted more commonly in the CCAP group than in the CAP group (p < 0.001).

CONCLUSION

Findings related to hypoxia, respiratory distress, and pleural effusion on imaging are important distinguishing factors associated with the development of complications in patients hospitalized with CAP. Therefore, CCAP etiology, diagnosis, and treatment approaches should be established and protective measures adopted.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Long-term outcomes of necrotizing pneumonia

INTRODUCTION

Necrotizing pneumonia (NP) is a serious complication of community-acquired pneumonia characterised by the destruction of normal lung parenchyma. No study has evaluated the repercussions of the lung damage in the years following the episode. The aim of this study was to assess the long-term impact on lung function and respiratory symptoms in children hospitalised due to NP.

METHODS

We analysed outcomes in children given a diagnosis of NP between January 2003 and April 2016. We selected patients aged more than 4 years capable of undergoing a lung function test, that had been followed up for at least 2 years. The patients completed a respiratory questionnaire and underwent a lung function test.

RESULTS

We included a total of 24 patients (12 male). The median age at the time of diagnosis was 28 months, the median length of stay was 15 days, and 18 patients required pleural drainage. The mean duration of follow-up after NP was 8.75 years. During the evaluation, none of the patients exhibited asthma, cough, or exercise-induced symptoms. Three children had a second episode of pneumonia that did not require hospital admission. The spirometry results were the following (given as mean±standard deviation): FEV1 Z-score, -0.47±0.65; FVC Z-score, -0.56±0.73; and FEV1/FVC Z-score, 0.19±0.98. We found no evidence of obstructive pulmonary disease or restrictive patterns.

CONCLUSIONS

The long-term outcomes of paediatric NP are good. However, patients exhibited mildly impaired lung function several years after the episode. We recommend follow-up of these patients due to potential impairments in lung function in adulthood.

Neonatal Manifestations of Chronic Granulomatous Disease: MAS/HLH and Necrotizing Pneumonia as Unusual Phenotypes and Review of the Literature

Chronic granulomatous disease (CGD) is a rare inborn error of immunity (IEI), characterized by a deficient phagocyte killing due to the inability of NADPH oxidase to produce reactive oxygen species in the phagosome. Patients with CGD suffer from severe and recurrent infections and chronic inflammatory disorders. Onset of CGD has been rarely reported in neonates and only as single case reports or small case series. We report here the cases of three newborns from two different kindreds, presenting with novel infectious and inflammatory phenotypes associated with CGD. A girl with CYBA deficiency presented with necrotizing pneumonia, requiring a prolonged antibiotic treatment and resulting in fibrotic pulmonary changes. From the second kindred, the first of two brothers developed a fatal Burkholderia multivorans sepsis and died at 24 days of life. His younger brother had a diagnosis of CYBB deficiency and presented with Macrophage Activation Syndrome/Hemophagocytic Lympho-Histiocytosis (MAS/HLH) without any infection, that could be controlled with steroids. We further report the findings of a review of the literature and show that the spectrum of microorganisms causing infections in neonates with CGD is similar to that of older patients, but the clinical manifestations are more diverse, especially those related to the inflammatory syndromes. Our findings extend the spectrum of the clinical presentation of CGD to include unusual neonatal phenotypes. The recognition of the very early, potentially life-threatening manifestations of CGD is crucial for a prompt diagnosis, improvement of survival and reduction of the risk of long-term sequelae.

A Baffling Bump: A Case Report of an Unusual Chest Wall Mass in a Pediatric Patient

Introduction

Chest wall masses are rare in children, but the differential diagnosis is broad and can include traumatic injury, neoplasm, and inflammatory or infectious causes. We report a novel case of an eight-year-old, previously healthy female who presented to the emergency department (ED) with one month of cough, fevers, weight loss, and an anterior chest wall mass.

Case Report

The patient’s ultimate diagnosis was necrotizing pneumonia with pneumatocele extending into the chest wall. This case is notable for the severity of the patient’s pulmonary disease given its extension through the chest wall, and for the unique speciation of her infection.

Conclusion

Although necrotizing pneumonia is a rare complication of community-acquired pneumonia, it is important for the emergency physician to recognize it promptly as it indicates severe progression of pulmonary disease even in children with normal and stable vital signs, as in this case. The emergency physician should consider complications of pneumonia including pneumatocele and empyema necessitans when presented with an anterior chest wall mass in a pediatric patient. Additionally, point-of-care ultrasound was used in the ED to facilitate the diagnosis of this illness and was particularly useful in determining the continuity of the patient’s lung infection with her extrathoracic chest wall mass.

Necrotizing pneumonia with bronchopleural fistula as an uncommon complication of pneumonia in children: a case report

Necrotizing pneumonia is an uncommon but severe complication of community acquired pneumonia characterized by the development of necrosis, liquefaction, and cavitation of the lung parenchyma. It occurs infrequently in children, ranging from 0.8% to 7% of community acquired pneumonia cases. We reported a case of 28-month-old female infant with a history of severe dyspnea and fever 5 days before admission. After administration of appropriate antibiotics for pneumonia, the patient's condition was still unresolved. Then, contrast CT scan showed cavitary lesions within consolidated lungs with loss of volume and lack of contrast enhancement that confirmed the diagnosis as necrotizing pneumonia. The presence of pneumothorax in the patient depicts a possible bronchopleural fistula which significantly increase morbidity and mortality risk. Surgical management could not be implemented due to worsening condition of the patient. It is suggested that patients with suspicion of necrotizing pneumonia are subjected to chest CT scan to avoid delay in diagnosis and appropriate management.

Early recognition of necrotizing pneumonia in children based on non-contrast-enhanced computed tomography radiomics signatures

BACKGROUND

Necrotizing pneumonia (NP) is an infrequent but severe complication of pneumonia in children. In the early stages of NP, CT imaging shows lung consolidation, which cannot be detected in time. This study aimed to explore the ability of non-contrast-enhanced CT radiomics features to recognize NP in early stage.

METHODS

This was a retrospective study, and 250 patients who presented with lung consolidation on initial CT images were included in this study. After a follow-up period of 1-3 weeks, 116 patients developed NP, whose CT or X-ray shows cavitation or liquefied necrosis. Manual segmentation of lesion sites in the initial non-contrast-enhanced CT scans was performed with RadCloud (Huiying Medical Technology Co., Ltd., China), and 1,409 radiomics features were extracted. We used Variance threshold (0.8), SelectKBest, and the least absolute shrinkage and selection operator (LASSO) methods for feature dimension reduction. Three machine learning algorithms, k-nearest neighbor (KNN), support vector machine (SVM), and logistic regression (LR) models, were established to recognize NP early. To assess the recognition performance, the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and other indicators were used in the validation cohort.

RESULTS

Radiomics features helped to recognize NP in early stage in both the training and validation cohorts. The AUC (sensitivity, specificity) for the training and validation cohorts were 0.81 (0.73, 0.68) and 0.71 (0.61, 0.65) for KNN, respectively; 0.81 (0.72, 0.70) and 0.77 (0.66, 0.65) for SVM, respectively; and 0.82 (0.73, 0.73) and 0.76 (0.63, 0.70) for LR, respectively. Recall and F1-scores determined that LR performed better at diagnosing early NP, with the values of the above two indexes being 0.70 and 0.67, respectively.

CONCLUSIONS

Non-contrast-enhanced CT-based radiomics models may be helpful for recognizing NP in early stage.

Complications in community acquired pneumonia: magnitude of problem, risk factors, and management in pediatric age

Introduction: In the last decades, the large use of several effective vaccines has dramatically reduced the incidence of community acquired pneumonia (CAP) in infants and children. Moreover, the availability of new antibiotics effective against emerging resistant strains of bacteria has greatly improved the early and long-term prognosis of this disease.Areas covered: The aim of this manuscript is to evaluate the burden of complicated CAP in pediatric age and to discuss its appropriate management.Expert opinion: Complicated CAP remains a problem for children in industrialized and developing countries. A larger use of lung ultrasonography (US) as first diagnostic approach could significantly improve early identification of cases at higher risk of complications. Difficult to solve, is the problem of the use of an antibiotic therapy able to assure adequate control in all the CAP cases, including those at high risk of or with already established complications. All these findings reveal that control of the incidence of complicated CAP remains difficult and will not be significantly changed in the next few years. Any attempt to improve complicated CAP management must be made. Consensus documents on better definition of the use of corticosteroids, fibrinolytic agents, and interventional procedures (including surgery) can allow us to reach this goal.

Staphylococcus aureus Arsenal To Conquer the Lower Respiratory Tract

Staphylococcus aureus is both a commensal and a pathogenic bacterium for humans. Its ability to induce severe infections is based on a wide range of virulence factors. S. aureus community-acquired pneumonia (SA-CAP) is rare and severe, and the contribution of certain virulence factors in this disease has been recognized over the past 2 decades. First, the factors involved in metabolism adaptation are crucial for S. aureus survival in the lower respiratory tract, and toxins and enzymes are required for it to cross the pulmonary epithelial barrier. S. aureus subsequently faces host defense mechanisms, including the epithelial barrier, but most importantly the immune system. Here, again, S. aureus uses myriad virulence factors to successfully escape from the host’s defenses and takes advantage of them. The impact of S. aureus virulence, combined with the collateral damage caused by an overwhelming immune response, leads to severe tissue damage and adverse clinical outcomes. In this review, we summarize step by step all of the S. aureus factors implicated in CAP and described to date, and we provide an outlook for future research.

miR-140-5p Overexpression Protects Against Lipopolysaccharide-Induced Necrotizing Pneumonia via Targeting Toll-Like Receptor 4

Objective

This study is to identify the effects of miRNA-140-5p on necrotizing pneumonia (NP) and its underlying mechanism.

Methods

The mRNA levels of miRNA-140-5p and TLR4 and secretion of IL-1β, IL-6, and TNF-α in peripheral blood from children with NP and healthy volunteers were determined using qRT-PCR and specific ELISAs. The interactions between miRNA-140-5p and TLR4 were investigated using a dual-luciferase reporter system. Cell viabilities were determined using a CCK-8 assay. qRT-PCR, western blotting, and specific ELISAs were applied to determine the expressions of genes in the cells. Peripheral blood from children with NP had significantly elevated levels of TLR4 but significantly lower levels of miR-140-5p compared to the control.

Results

Spearman's rank correlation analysis showed a negative correlation between TLR4 and miR-140-5p. miR-140-5p regulated the expressions of TLR4 in A549 cells. Additionally, LPS induced a significant enhancement in the levels of TLR4 but significant reduction in the levels of miR-140-5p. The overexpression of miR-140-5p suppressed cell apoptosis and induced the release of inflammatory cytokines in the LPS-induced A549 cells.

Conclusion

The underlying mechanisms of miR-140-5p on the regulation of TLR4 are in part by the regulation of p65. The miR-140-5p inhibits necrotizing pneumonia by regulating TLR-4 via TNF-p65 signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-021-00673-0.

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.

Regulation and Function of ILC3s in Pulmonary Infections

Lower respiratory infections are among the leading causes of morbidity and mortality worldwide. These potentially deadly infections are further exacerbated due to the growing incidence of antimicrobial resistance. To combat these infections there is a need to better understand immune mechanisms that promote microbial clearance. This need in the context of lung infections has been further heightened with the emergence of SARS-CoV-2. Group 3 innate lymphoid cells (ILC3s) are a recently discovered tissue resident innate immune cell found at mucosal sites that respond rapidly in the event of an infection. ILC3s have clear roles in regulating mucosal immunity and tissue homeostasis in the intestine, though the immunological functions in lungs remain unclear. It has been demonstrated in both viral and bacterial pneumonia that stimulated ILC3s secrete the cytokines IL-17 and IL-22 to promote both microbial clearance as well as tissue repair. In this review, we will evaluate regulation of ILC3s during inflammation and discuss recent studies that examine ILC3 function in the context of both bacterial and viral pulmonary infections.

A Child with Influenza A and Large Pneumatocele

: Necrotizing pneumonia (NP) is a rare complication of community-acquired pneumonia, which occurs in patients with viral pneumonia such as influenza and secondary bacterial infection. We present a five-year-old boy with cough and dyspnea and low SpO2, who was admitted to PICU. He was intubated, and two-sided chest tubes were placed because of pleural effusion. Nasopharyngeal RT-PCR for H1N1 was positive. Subcutaneous and mediastinal emphysema and a large pneumatocele developed concomitantly, and the patient underwent three times percutaneous aspiration of pneumatocele under anesthesia and CT scan guide without surgery. The size of the pneumatocele decreased, and the patient was extubated. After one month of admission, he was discharged in good condition and no pulmonary sequela.

Unusual case of necrotizing pneumonia caused by Fusobacterium nucleatum complicating influenza a virus infection

We report a rare case of Fusobacterium nucleatum necrotizing pneumonia following an influenza viral infection. This rare bacterial lung infection can have severe complications such as respiratory failure and septic shock, so early recognition and treatment are necessary.

A Successful Medical Treatment of Necrotizing Pneumonia in a Pediatric Patient

Necrotizing pneumonia is a rare, serious complication of pneumonia in children. We present a case of a 20-month-old girl presenting with respiratory distress which later be diagnosed with necrotizing pneumonia. In this paper, we highlight the role of imaging such as chest X-ray, chest CT, and lung ultrasonography for diagnosis and the importance of intravenous antibiotic therapy for better outcome.

Contrast-enhanced ultrasound of pediatric lungs

In addition to radiography, ultrasound (US) has long proved to be a valuable imaging modality to evaluate the pediatric lung and pleural cavity. Its many inherent advantages, including real-time performance, high spatial resolution, lack of ionizing radiation and lack of need for sedation make it preferable over other imaging modalities such as CT. Since the introduction of ultrasound contrast agents (UCAs), contrast-enhanced ultrasound (CEUS) has become a valuable complementary US technique, with many well-established uses in adults and evolving uses in children. Lung CEUS applications are still not licensed and are performed off-label, although the added value of CEUS in certain clinical scenarios is increasingly reported. The limited evidence of CEUS in the evaluation of pediatric lungs focuses primarily on community-acquired pneumonia and its complications. In this clinical setting, CEUS is used to confidently and accurately diagnose necrotizing pneumonia and to delineate pleural effusions and empyema. In addition to intravenous use, UCAs can be administered directly into the pleural cavity through chest catheters to improve visualization of loculations within a complex pleural effusion, which might necessitate fibrinolytic therapy. The purpose of this paper is to present the current experience on pediatric lung CEUS and to suggest potential additional uses that can be derived from adult studies.

Emergent Pneumonia in Children

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

Severe Necrotizing Pneumonia in Children: A Challenge to Intensive Care Specialist

OBJECTIVE

Necrotizing pneumonia (NP) is recently recognized as a complication of pneumonia. The data on NP are scant from developing world and we aimed to describe the characteristic features of NP in our children.

STUDY DESIGN

Single center retrospective cohort analysis.

PATIENT SELECTION

Institutional database of children treated for pneumonia between September 2014 and May 2018 was searched to identify children with NP.

METHODS

The demographic characteristics, laboratory results, and clinical information were recorded for patients selected as NP and analyzed.

RESULTS

In total, 10 patients (3.7%) of NP were identified out of 272 patients with pneumonia. Median age was 3 years (range: 3 months to 12years). All cases had severe respiratory distress and 70% required mechanical ventilation and inotropic support. The causative pathogens were identified in 6/10 children (60%) with Staphylococcus aureus being most common (4/10). Pleural effusion and pneumothorax were seen in six cases. Four cases had bilateral pleural effusion and three had bilateral pneumothorax. Intercostal drainage (ICD) was placed in 70% and bilateral ICD was placed in 40% cases. Bronchopleural fistula (BPF) developed in two cases and one had bilateral BPF. Median [inter quartile range] ICD days and hospital stay were 9 (6-14) and 13.5 (7.5-18.5) days, respectively. Mean (±SD) total antibiotic (in hospital plus outpatient) days were 28.8 ± 9.6 days. Four cases had airway hemorrhage and in three cases this was massive and fatal.

CONCLUSION

NP is a relatively rare but severe complication of pneumonia distinct from pediatric acute respiratory distress, pleural effusion and empyema. Airway hemorrhage is the most fatal complication.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

[Long-term outcomes of necrotizing pneumonia]

INTRODUCTION

Necrotizing pneumonia (NP) is a serious complication of community-acquired pneumonia characterised by the destruction of normal lung parenchyma. No study has evaluated the repercussions of the lung damage in the years following the episode. The aim of this study was to assess the long-term impact on lung function and respiratory symptoms in children hospitalised due to NP.

METHODS

We analysed outcomes in children given a diagnosis of NP between January 2003 and April 2016. We selected patients aged more than 4 years capable of undergoing a lung function test, that had been followed up for at least 2 years. The patients completed a respiratory questionnaire and underwent a lung function test.

RESULTS

We included a total of 24 patients (12 male). The median age at the time of diagnosis was 28 months, the median length of stay was 15 days, and 18 patients required pleural drainage. The mean duration of follow-up after NP was 8.75 years. During the evaluation, none of the patients exhibited asthma, cough, or exercise-induced symptoms. Three children had a second episode of pneumonia that did not require hospital admission. The spirometry results were the following (given as mean ± standard deviation): FEV1 z-score, -0.47±0.65; FVC z-score, -0.56±0.73; and FEV1/FVC z-score, 0.19±0.98. We found no evidence of obstructive pulmonary disease or restrictive patterns.

CONCLUSIONS

The long-term outcomes of paediatric NP are good. However, patients exhibited mildly impaired lung function several years after the episode. We recommend follow-up of these patients due to potential impairments in lung function in adulthood.