Combination of clinical symptoms and blood biomarkers can improve discrimination between bacterial or viral community-acquired pneumonia in children

Working group summary of the 2023 full update of the Finnish national guidelines for paediatric lower respiratory tract infections

AIM

The first evidence-based Finnish guidelines for paediatric lower respiratory tract infections (LRTIs) were published in 2014 and completely updated in 2023. This paper, by the interdisciplinary working group that developed the 2023 guidelines, summarises the main recommendations.

METHODS

The 2023 guidelines were produced after a systematic review. Strong evidence was at least two separate, high-quality studies, moderate evidence was at least one high-quality study and weak evidence was at least one satisfactory study. The authors have now summarised the key points.

RESULTS

There was strong evidence that antitussives and beta-sympathomimetics were not effective for bronchitis-related cough and that laryngitis should be treated with oral corticosteroids, with adrenaline inhalations added in severe cases. Also, that amoxicillin for 5 days provided sufficient treatment for paediatric community-acquired pneumonia and that children with apparent viral pneumonia could be observed without antimicrobial therapy. There was moderate evidence that corticosteroids or inhaled agents were not effective for bronchiolitis and that administering salbutamol with a holding chamber could relieve symptoms of wheezing bronchitis. Also, pertussis should be considered for unvaccinated infants with coughs.

CONCLUSION

The 2023 guidelines aim to improve acute evidence-based treatment of LRTIs, through appropriate antibiotics, inhaled drugs, corticosteroids, radiology and laboratory testing.

Pathogen distribution and infection patterns in pediatric severe pneumonia: A targeted next-generation sequencing study

OBJECTIVE

Severe pneumonia in children represents a significant clinical challenge due to its high incidence and associated mortality. This study aimed to assess the distribution of pathogens and patterns of infection in pediatric patients with severe pneumonia.

METHODS

This study included 110 pediatric patients diagnosed with severe pneumonia, who were admitted to Guangxi Maternal and Child Health Hospital between July 2021 and November 2023. Pathogen-targeted next-generation sequencing (tNGS) was employed to identify respiratory pathogens in these cases.

RESULTS

Pathogens were detected in 109 out of 110 cases, yielding a positive detection rate of 99.09%. Among these cases, 25 (22.72%) involved single-pathogen infections, while 84 (76.36%) were characterized by mixed infections. The infection pattern in children with severe pneumonia was relatively common with bacterial-viral coinfection (28.2%, 31/110). A total of 39 pathogens were identified from the 110 children with severe pneumonia, with the top three pathogens being Mycoplasma pneumoniae (30.91%, 34/110), Human Respiratory Syncytial Virus Type A (26.36%, 29/110), and Human Herpesvirus (18.18%, 20/110). Notably, 38.2% (13/34) of the cases were found to have macrolide-resistant Mycoplasma pneumoniae (MRMP). Additionally, 40% (44/110) of the children required admission to the intensive care unit (ICU).

CONCLUSION

The application of tNGS demonstrates significant utility in the detection of pathogens in pediatric patients with severe pneumonia. The predominant pathogens identified in this study are Mycoplasma pneumoniae, Human Respiratory Syncytial Virus, and Human Herpesvirus. Furthermore, mixed infections involving multiple pathogens were observed in 76.36% of the cases, and a substantial proportion (40%) of these patients necessitated intensive care.

Metabolomic Profiling Reveals That Exercise Lowers Biomarkers of Cardiac Dysfunction in Rats with Type 2 Diabetes

The increasing prevalence of type 2 diabetes mellitus (T2DM) leads to significant global health challenges, including cardiac structural and functional deficits, which in severe cases can progress to heart failure that can further strain healthcare resources. Aerobic exercise can ameliorate cardiac dysfunction in individuals with diabetes, although a comprehensive understanding of its underlying mechanisms remains elusive. This study utilizes untargeted metabolomics to reveal aerobic-exercise-activated metabolic biomarkers in the cardiac tissues of Sprague Dawley rats with T2DM. Metabolomics analysis revealed that diabetes altered 1029 myocardial metabolites, while aerobic exercise reversed 208 of these metabolites, of which 112 were upregulated and 96 downregulated. Pathway topology analysis suggested that these metabolites predominantly contributed to purine metabolism and arginine biosynthesis. Furthermore, receiver operating characteristic curve analysis identified 10 potential biomarkers, including xanthine, hypoxanthine, inosine, dGMP, l-glutamic acid, l-arginine, l-tryptophan, (R)-3-hydroxybutyric acid, riboflavin, and glucolepidiin. Finally, data from Pearson correlation analysis indicated that some metabolic biomarkers strongly correlated with cardiac function. Our data suggest that certain metabolic biomarkers play an important role in ameliorating diabetes-related cardiac dysfunction by aerobic exercise.

The Diagnostic Association of Radiological and Clinicopathological Parameters in Community-Acquired Pneumonia in Children: A Cross-Sectional Study

Background Globally, pneumonia is one of the significant causes of death in children under the age of five years. Assessment of disease severity is essential for clinical decision-making. Clinicians in resource-limited settings use the WHO Integrated Management of Childhood Illness (IMNCI) guidelines to diagnose and treat pneumonia. Chest X-rays and blood biomarkers are frequently performed in children presenting with pneumonia, but their role in clinical decision-making is limited. Objective To evaluate the association of chest X-ray results, clinical parameters, and blood inflammatory biomarkers with the severity of community-acquired pneumonia (CAP) in children to decide which tests are helpful in accurately classifying the severity of pneumonia. Methods This cross-sectional, analytical study was conducted at the Combined Military Hospital, Lahore, among 421 children aged two months to five years who were admitted with complaints of cough and difficulty breathing and were COVID-19 negative. Data was collected through a structured questionnaire, including demographic information and clinical categorization of pneumonia severity using WHO criteria, SpO2 levels, chest X-rays, complete blood count (CBC), and C-reactive protein (CRP) levels obtained within 24 hours of admission. Statistical evaluation of 323 children was done using SPSS version 26, and analysis of variance (ANOVA), chi-square test, and Fisher's exact test were applied to determine statistical significance. p-Value <0.05 was considered significant. Results The median age of the study population was eight months (IQR: 3-20 months); 113 (33.1%) were girls and 127 (37.2%) were underweight children. Eighteen (5.3%) patients had no pneumonia, 245 (71.8%) patients had non-severe pneumonia, and 78 (22.9%) patients had severe pneumonia. The clinical features of severe pneumonia were more common in children with radiologic findings of alveolar CAP than non-alveolar CAP (36.2% and 20%, respectively, p: 0.05). A higher percentage of patients with alveolar CAP had CRP >6 mg/dL than non-alveolar CAP (69.9% and 35%, respectively, p < 0.001). Patients with undernutrition (WAZ <-2 SD), hypoxemia (SpO2 <95%), and having CRP >6 mg/dL were associated with clinical features of severe pneumonia (46.1% vs. 33.8%, 100% vs 47.3%, and 67.9% vs 48.5%, respectively, p < 0.05). A significantly greater frequency of a bilateral multifocal distribution (p = 0.020), and the involvement of the right paracardiac region (p = 0.043) and the left lower lobe (p = 0.007) in those with severe pneumonia was observed. Conclusion Clinical diagnosis of pneumonia, along with the assessment of risk factors, including undernutrition and hypoxemia, should be adequate to diagnose pneumonia in children. Chest X-rays and CRP levels can be helpful in hospitalized children for whom physicians have difficulty deciding about antibiotic prescriptions, but their role in routinely classifying the severity of pneumonia in children is limited.

Comparative analysis of immunological biomarkers in COVID-19 and bacterial pneumonia

Coronavirus disease 2019 (COVID-19) is a severe and infectious respiratory condition caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This case-control study aimed to evaluate serum levels of various immunological markers in patients with COVID-19 compared to those with bacterial pneumonia and a healthy control group. Serum samples were collected from adult participants across various COVID-19 isolation centers, including Kassala State and Ahmed Gasim Hospital, between April and June 2021. The study included 70 patients diagnosed with COVID-19, 30 with bacterial pneumonia, and 50 healthy controls. Serum levels of C-reactive protein (CRP), complement components C3 and C4, and cytokines IL-8, IL-10, IL-12, TNF-α, and IFN-γ were measured using standard reagent kits. Serum level of CRP was significantly elevated in both bacterial pneumonia and COVID-19 but significantly higher among patients with bacterial pneumonia. C3 and C4 were also increased in both patient groups, with C3 significantly higher in bacterial pneumonia. IL-8, IL-10, IL-12, TNF-α, and IFN-γ were significantly increased in bacterial pneumonia and SARS-Cov-2 compared to healthy controls. However, IFN-γ was significantly increased among patients with COVID-19 than patients with bacterial pneumonia. This study highlights the potential significant impact of COVID-19 on the immunological biomarkers investigated.

Antibiotic failure: Beyond antimicrobial resistance

Despite significant progress in antibiotic discovery, millions of lives are lost annually to infections. Surprisingly, the failure of antimicrobial treatments to effectively eliminate pathogens frequently cannot be attributed to genetically-encoded antibiotic resistance. This review aims to shed light on the fundamental mechanisms contributing to clinical scenarios where antimicrobial therapies are ineffective (i.e., antibiotic failure), emphasizing critical factors impacting this under-recognized issue. Explored aspects include biofilm formation and sepsis, as well as the underlying microbiome. Therapeutic strategies beyond antibiotics, are examined to address the dimensions and resolution of antibiotic failure, actively contributing to this persistent but escalating crisis. We discuss the clinical relevance of antibiotic failure beyond resistance, limited availability of therapies, potential of new antibiotics to be ineffective, and the urgent need for novel anti-infectives or host-directed therapies directly addressing antibiotic failure. Particularly noteworthy is multidrug adaptive resistance in biofilms that represent 65 % of infections, due to the lack of approved therapies. Sepsis, responsible for 19.7 % of all deaths (as well as severe COVID-19 deaths), is a further manifestation of this issue, since antibiotics are the primary frontline therapy, and yet 23 % of patients succumb to this condition.

Antibiotic Prescribing for Lower Respiratory Tract Infections and Community-Acquired Pneumonia: An Italian Pediatric Emergency Department's Real-Life Experience

BACKGROUND

Lower respiratory tract infections (LRTIs) and community-acquired pneumonia (CAP) are among the most frequent reasons for referrals to the pediatric emergency department (PED). The aim of this study is to describe the management of antibiotic prescription in febrile children with LRTI or CAP admitted to a third-level PED and to investigate the different variables that can guide physicians in this decision-making.

METHODS

This is an observational, retrospective, monocentric study including patients < 14 years old who were presented to the PED for a febrile LRTI or CAP during the first six months of the year 2017. Demographic and clinical data, PED examinations, recommended therapy, and discharge modality were considered. Two multivariate logistic regression analyses were performed on patients with complete profiles to investigate the impact of demographic, laboratory, and clinical variables on antibiotic prescription and hospital admission.

RESULTS

This study included 584 patients with LRTI (n = 368) or CAP (n = 216). One hundred and sixty-eight individuals (28.7%) were admitted to the hospital. Lower age, higher heart rate, and lower SpO2 were associated with an increased risk of hospitalization. Antibiotics were prescribed to 495 (84.8%) patients. According to the multivariate logistic regression, the diagnosis and duration of fever were substantially linked with antibiotic prescription.

CONCLUSIONS

The present study reports real-life data about our PED experience. A high rate of antibiotic prescription was noted. In the future, it is necessary to improve antibiotic stewardship programs to increase clinical adherence to guidelines.

Epidemiologic, clinical, and serum markers may improve discrimination between bacterial and viral etiologies of childhood pneumonia

Background

Discrimination of bacterial and viral etiologies of childhood community-acquired pneumonia (CAP) is often challenging. Unnecessary antibiotic administration exposes patients to undue risks and may engender antimicrobial resistance. This study aimed to develop a prediction model using epidemiological, clinical and laboratory data to differentiate between bacterial and viral CAP.

Methods

Data from 155 children with confirmed bacterial or mixed bacterial and viral infection (N = 124) and viral infection (N = 31) were derived from a comprehensive assessment of causative pathogens [Partnerships for Enhanced Engagement in Research-Pneumonia in Pediatrics (PEER-PePPeS)] conducted in Indonesia. Epidemiologic, clinical and biomarker profiles (hematology and inflammatory markers) were compared between groups. The area under the receiver operating characteristic curve (AUROC) for varying biomarker levels was used to characterize performance and determine cut-off values for discrimination of bacterial and mixed CAP versus viral CAP. Diagnostic predictors of bacterial and mixed CAP were assessed by multivariate logistic regression.

Results

Diarrhea was more frequently reported in bacterial and mixed CAP, while viral infections more frequently occurred during Indonesia's rainy season. White blood cell counts (WBC), absolute neutrophil counts (ANC), neutrophil-lymphocyte ratio (NLR), C-reactive protein (CRP), and procalcitonin (PCT) were significantly higher in bacterial and mixed cases. After adjusting for covariates, the following were the most important predictors of bacterial or mixed CAP: rainy season (aOR 0.26; 95% CI 0.08-0.90; p = 0.033), CRP ≥5.70 mg/L (aOR 4.71; 95% CI 1.18-18.74; p = 0.028), and presence of fever (aOR 5.26; 95% CI 1.07-25.91; p = 0.041). The model assessed had a low R-squared (Nagelkerke R² = 0.490) but good calibration (p = 0.610 for Hosmer Lemeshow test). The combination of CRP and fever had moderate predictive value with sensitivity and specificity of 62.28 and 65.52%, respectively.

Conclusion

Combining clinical and laboratory profiles is potentially valuable for discriminating bacterial and mixed from viral pediatric CAP and may guide antibiotic use. Further studies with a larger sample size should be performed to validate this model.

Predicting the causative pathogen among children with pneumonia using a causal Bayesian network

BACKGROUND

Pneumonia remains a leading cause of hospitalization and death among young children worldwide, and the diagnostic challenge of differentiating bacterial from non-bacterial pneumonia is the main driver of antibiotic use for treating pneumonia in children. Causal Bayesian networks (BNs) serve as powerful tools for this problem as they provide clear maps of probabilistic relationships between variables and produce results in an explainable way by incorporating both domain expert knowledge and numerical data.

METHODS

We used domain expert knowledge and data in combination and iteratively, to construct, parameterise and validate a causal BN to predict causative pathogens for childhood pneumonia. Expert knowledge elicitation occurred through a series of group workshops, surveys and one-on-one meetings involving 6-8 experts from diverse domain areas. The model performance was evaluated based on both quantitative metrics and qualitative expert validation. Sensitivity analyses were conducted to investigate how the target output is influenced by varying key assumptions of a particularly high degree of uncertainty around data or domain expert knowledge.

RESULTS

Designed to apply to a cohort of children with X-ray confirmed pneumonia who presented to a tertiary paediatric hospital in Australia, the resulting BN offers explainable and quantitative predictions on a range of variables of interest, including the diagnosis of bacterial pneumonia, detection of respiratory pathogens in the nasopharynx, and the clinical phenotype of a pneumonia episode. Satisfactory numeric performance has been achieved including an area under the receiver operating characteristic curve of 0.8 in predicting clinically-confirmed bacterial pneumonia with sensitivity 88% and specificity 66% given certain input scenarios (i.e., information that is available and entered into the model) and trade-off preferences (i.e., relative weightings of the consequences of false positive versus false negative predictions). We specifically highlight that a desirable model output threshold for practical use is very dependent upon different input scenarios and trade-off preferences. Three commonly encountered scenarios were presented to demonstrate the potential usefulness of the BN outputs in various clinical pictures.

CONCLUSIONS

To our knowledge, this is the first causal model developed to help determine the causative pathogen for paediatric pneumonia. We have shown how the method works and how it would help decision making on the use of antibiotics, providing insight into how computational model predictions may be translated to actionable decisions in practice. We discussed key next steps including external validation, adaptation and implementation. Our model framework and the methodological approach can be adapted beyond our context to broad respiratory infections and geographical and healthcare settings.

Serum-integrated omics reveal the host response landscape for severe pediatric community-acquired pneumonia

OBJECTIVE

Community-acquired pneumonia (CAP) is the primary cause of death for children under five years of age globally. Hence, it is essential to investigate new early biomarkers and potential mechanisms involved in disease severity.

METHODS

Proteomics combined with metabolomics was performed to identify biomarkers suitable for early diagnosis of severe CAP. In the training cohort, proteomics and metabolomics were performed on serum samples obtained from 20 severe CAPs (S-CAPs), 15 non-severe CAPs (NS-CAPs) and 15 healthy controls (CONs). In the verification cohort, selected biomarkers and their combinations were validated using ELISA and metabolomics in an independent cohort of 129 subjects. Finally, a combined proteomics and metabolomics analysis was performed to understand the major pathological features and reasons for severity of CAP.

RESULTS

The proteomic and metabolic signature was markedly different between S-CAPs, NS-CAPs and CONs. A new serum biomarker panel including 2 proteins [C-reactive protein (CRP), lipopolysaccharide (LBP)] and 3 metabolites [Fasciculol C, PE (14:0/16:1(19Z)), PS (20:0/22:6(4Z, 7Z, 10Z, 13Z, 16Z, 19Z))] was developed to identify CAP and to distinguish severe pneumonia. Pathway analysis of changes revealed activation of the cell death pathway, a dysregulated complement system, coagulation cascade and platelet function, and the inflammatory responses as contributors to tissue damage in children with CAP. Additionally, activation of glycolysis and higher levels of nucleotides led to imbalanced deoxyribonucleotide pools contributing to the development of severe CAP. Finally, dysregulated lipid metabolism was also identified as a potential pathological mechanism for severe progression of CAP.

CONCLUSION

The integrated analysis of the proteome and metabolome might open up new ways in diagnosing and uncovering the complexity of severity of CAP.

Modern approaches at the management of children with community-acquired pneumonia

Experts of The Union of Pediatricians of Russia have developed current clinical guidelines for management of children with community-acquired pneumonia, which were approved by the Scientific and Practice Council of Ministry of Public Health of the Russian Federation in January 2022. Particular attention is paid to the etiological structure, modern classification, diagnostic tests and flagship approaches to antibacterial therapy of community-acquired pneumonia in children based on the principles of evidentiary medicine. 

The addition of point-of-care test reduces antibiotic prescription in hospitalized children with suspected respiratory tract infection: a pretest-posttest study

AIM

Prompt and accurate etiological diagnostics are needed if physicians are to improve and target antibiotic treatment. We aimed to investigate if antibiotic-prescribing decisions are improved with availability of point-of-care polymerase chain reaction (POC-PCR) diagnostic testing of children with suspected respiratory tract infection, and if it had an impact on referral for additional medical procedures.

METHODS

This was a single centre one-group pretest-posttest study. Children visiting our Pediatric Department with respiratory tract infection symptoms were included if the treating pediatrician was considering an antibiotic prescription. Throat swabs were analysed for pathogens using POC-PCR. The pediatrician registered treatment decisions, referrals for additional procedures, and decisions about hospitalization into a questionnaire before and after receiving the POC-PCR results.

RESULTS

We included 95 children. The availability of results from POC-PCR analysis significantly changed the prescriped antibiotic treatment to non-antibiotic treatment in 46% (36%-56%) of the children and the reverse in 2% (1%-8%). Pediatricians referred significantly fewer patients to additional medical procedures with availability of POC-PCR.

CONCLUSION

POC-PCR significantly reduced the odds of antibiotic prescription, and referral for additional medical procedures. Thus, POC-PCR presents an opportunity to improve antibiotic prescribing practices if it is combined with standard clinical evaluation.

Respiratory etiological surveillance among quarantined patients with suspected lower respiratory tract infection at a medical center in southern Taiwan during COVID-19 pandemic

Background

A comprehensive study of respiratory pathogens was conducted in an area with a low prevalence of COVID-19 among the adults quarantined at a tertiary hospital.

Methods

From March to May 2020, 201 patients suspected lower respiratory tract infection (LRTI) were surveyed for etiologies by multiplex polymerase chain reaction (PCR: FilmArray TM Respiratory Panel) test combination with cultural method, viral antigen detection and serologic surveys.

Results

Total 201 patients tested with FilmArray TM Respiratory Panel were enrolled, of which 68.2% had sputum bacterial culture, 86.1% had pneumococcus and Legionella urine antigen test. Their median age was 72.0 year-old with multiple comorbidities, and 11.4% were nursing home residents. Bacteria accounted for 59.7% of identified pathogens. Atypical pathogens were identified in 31.3% of total pathogens, of which viruses accounted for 23.9%. In comparison to patients with bacterial infection, patients with atypical pathogens were younger (median= 77.2 vs 67.1, years, P = 0.017) and had shorter length of hospital (8.0 vs 4.5, days, P = 0.007).

Conclusions

Patients with LRTI caused by atypical pathogens was indistinguishable from those with bacterial pathogens by clinical manifestations or biomarkers. Multiplex PCR providing rapid diagnosis of atypical pathogens enhance patient care and decision making when rate of sputum culture sampling was low in quarantine ward during pandemic.

Chest Radiographs Using a Context-Fusion Convolution Neural Network (CNN): Can It Distinguish the Etiology of Community-Acquired Pneumonia (CAP) in Children?

Clinical symptoms and inflammatory markers cannot reliably distinguish the etiology of CAP, and chest radiographs have abundant information related with CAP. Hence, we developed a context-fusion convolution neural network (CNN) to explore the application of chest radiographs to distinguish the etiology of CAP in children. This retrospective study included 1769 cases of pediatric pneumonia (viral pneumonia, n = 487; bacterial pneumonia, n = 496; and mycoplasma pneumonia, n = 786). The chest radiographs of the first examination, C-reactive protein (CRP), and white blood cell (WBC) were collected for analysis. All patients were stochastically divided into training, validation, and test cohorts in a 7:1:2 ratio. Automatic lung segmentation and hand-crafted pneumonia lesion segmentation were performed, from which three image-based models including a full-lung model, a local-lesion model, and a context-fusion model were built; two clinical characteristics were used to build a clinical model, while a logistic regression model combined the best CNN model and two clinical characteristics. Our experiments showed that the context-fusion model which integrated the features of the full-lung and local-lesion had better performance than the full-lung model and local-lesion model. The context-fusion model had area under curves of 0.86, 0.88, and 0.93 in identifying viral, bacterial, and mycoplasma pneumonia on the test cohort respectively. The addition of clinical characteristics to the context-fusion model obtained slight improvement. Mycoplasma pneumonia was more easily identified compared with the other two types. Using chest radiographs, we developed a context-fusion CNN model with good performance for noninvasively diagnosing the etiology of community-acquired pneumonia in children, which would help improve early diagnosis and treatment.

Tracheobronchitis in children with tracheostomy tubes: Overview of a challenging problem

Tracheobronchitis is common in children with tracheostomy tubes. These children are predisposed to respiratory infections due to the bypassing of normal upper airway defense mechanisms by the tracheostomy, bacterial colonization of the tracheostomy tube itself, and underlying medical conditions. Diagnosis of bacterial tracheobronchitis is challenging due to the difficulty in differentiating between bacterial colonization and infection, as well as between viral and bacterial etiologies. Difficulty in diagnosis complicates management decisions, and there are currently no consensus guidelines to assist clinicians in the treatment of these patients. Frequent administration of systemic antibiotics causes adverse effects and leads to the emergence of resistant organisms. Topical administration of antibiotics via nebulization or direct instillation may lead to a significantly higher concentration of drug in the upper and lower airways without causing systemic side effects, although therapeutic trials in children with tracheostomy tubes are lacking. Several preventative measures such as regular airway clearance and the use of a speaking valve may mitigate the risk of developing respiratory infections.

Association of Clinical Signs, Host Biomarkers and Etiology With Radiological Pneumonia in Bhutanese Children

Diagnosing pneumonia and identifying those requiring antibiotherapy remain challenging. Chest radiographs (CXR) are often used as the reference standard. We aimed to describe clinical characteristics, host-response biomarkers and etiology, and assess their relationship to CXR findings in children with pneumonia in Thimphu, Bhutan. Children between 2 and 59 months hospitalized with WHO-defined pneumonia were prospectively enrolled and classified into radiological endpoint and non-endpoint pneumonia. Blood and nasopharyngeal washing were collected for microbiological analyses and plasma levels of 11 host-response biomarkers were measured. Among 149 children with readable CXR, 39 (26.2%) presented with endpoint pneumonia. Identification of respiratory viruses was common, with no significant differences by radiological outcomes. No clinical sign was suggestive of radiological pneumonia, but children with radiological pneumonia presented higher erythrocyte sedimentation rate, C-reactive protein and procalcitonin. Markers of endothelial and immune activation had little accuracy for the reliable identification of radiological pneumonia.

Viruses and Mycoplasma pneumoniae are the main etiological agents of community-acquired pneumonia in hospitalized pediatric patients in Spain

OBJECTIVES

To describe the etiology of community-acquired pneumonia (CAP) in hospitalized children in Spain and analyze the predictors of the etiology.

HYPOTHESIS

The different etiological groups of pediatric CAP are associated with different clinical, radiographic, and analytical data.

DESIGN

Observational, multicenter, and prospective study.

PATIENT SELECTION

This study included children aged 1 month to 17 years with CAP, who were hospitalized between April 2012 and May 2019.

METHODS

An extensive microbiological workup was performed. The clinical, radiographic, and analytical parameters were analyzed for three etiological groups.

RESULTS

Among the 495 children included, at least one causative pathogen was identified in 262 (52.9%): pathogenic viruses in 155/262 (59.2%); atypical bacteria (AB), mainly Mycoplasma pneumonia, in 84/262 (32.1%); and typical bacteria (TyB) in 40/262 (15.3%). Consolidation was observed in 89/138 (64.5%) patients with viral CAP, 74/84 (88.1%) with CAP caused by AB, and 40/40 (100%) with CAP caused by TyB. Para-pneumonic pleural effusion (PPE) was observed in 112/495 (22.6%) patients, of which 61/112 (54.5%) presented a likely causative pathogen: viruses in 12/61 (19.7%); AB in 23/61 (37.7%); and TyB in 26/61 (42.6%). Viral etiology was significantly frequent in young patients and in those with low oxygen saturation, wheezing, no consolidation, and high lymphocyte counts. CAP patients with AB as the etiological agent had a significantly longer and less serious course as compared to those with other causative pathogens.

CONCLUSIONS

Viruses and M. pneumoniae are the main causes of pediatric CAP in Spain. Wheezing, young age, and no consolidation on radiographs are indicative of viral etiology. Viruses and AB can also cause PPE. Since only a few cases can be directly attributed to TyB, the indications for antibiotics must be carefully considered in each patient.

A Tool to Distinguish Viral From Bacterial Pneumonia

BACKGROUND

Establishing the etiology of community-acquired pneumonia (CAP) in children at admission is challenging. Most of the admitted children with CAP receive antibiotics. We aimed to build and validate a diagnostic tool combining clinical, analytical and radiographic features to differentiate viral from bacterial CAP, and among bacterial CAP, typical from atypical bacteria.

METHODS

Design-observational, multi-center, prospective cohort study was conducted in 2 phases. Settings: 24 secondary and tertiary hospitals in Spain. Patients-A total of 495 consecutive hospitalized children between 1 month and 16 years of age with CAP were enrolled. Interventions-A score with 2 sequential steps was built (training set, 70% patients, and validation set 30%). Step 1 differentiates between viral and bacterial CAP and step 2 between typical and atypical bacterial CAP. Optimal cutoff points were selected to maximize specificity setting a high sensitivity (80%). Weights of each variable were calculated with a multivariable logistic regression. Main outcome measures-Viral or bacterial etiology.

RESULTS

In total, 262 (53%) children (median age: 2 years, 52.3% male) had an etiologic diagnosis. In step 1, bacterial CAPs were classified with a sensitivity = 97%, a specificity = 48%, and a ROC's area under the curve = 0.81. If a patient with CAP was classified as bacterial, he/she was assessed with step 2. Typical bacteria were classified with a sensitivity = 100%, a specificity = 64% and area under the curve = 0.90. We implemented the score into a mobile app named Pneumonia Etiology Predictor, freely available at usual app stores, that provides the probability of each etiology.

CONCLUSIONS

This 2-steps tool can facilitate the physician's decision to prescribe antibiotics without compromising patient safety.

Clustering cases of Chlamydia psittaci pneumonia mimicking COVID-19 pneumonia

BACKGROUND

The onset symptoms of people infected by Chlamydia psittaci can mimic the coronavirus disease 2019 (COVID-19). However, the differences in laboratory tests and imaging features between psittacosis and COVID-19 remain unknown.

AIM

To better understand the two diseases and then make an early diagnosis and treatment.

METHODS

Six patients from two institutions confirmed as psittacosis by high-throughput genetic testing and 31 patients confirmed as COVID-19 were retrospectively included. The epidemiology, clinical characteristics, laboratory tests and computed tomography (CT) imaging features were collected and compared between the two groups. The follow-up CT imaging findings of patients with psittacosis were also investigated.

RESULTS

The white blood cell count (WBC), neutrophil count and calcium were more likely to be decreased in patients with COVID-19 but were increased in patients with psittacosis (all P = 0.000). Lymphocyte count and platelet count were higher in patients with psittacosis than in those with COVID-19 (P = 0.044, P = 0.035, respectively). Lesions in patients with psittacosis were more likely to be unilateral (P = 0.001), involve fewer lung lobes (P = 0.006) and have pleural effusions (P = 0.002). Vascular enlargement was more common in patients with COVID-19 (P = 0.003). Consolidation in lung CT images was absorbed in all 6 patients.

CONCLUSION

Psittacosis has the potential for human-to-human transmission. Patients with psittacosis present increased WBC count and neutrophil count and have specific CT imaging findings, including unilateral distribution, less involvement of lung lobes and pleural effusions, which might help us to differentiate it from COVID-19.

Optical Biosensors for Diagnostics of Infectious Viral Disease: A Recent Update

The design and development of biosensors, analytical devices used to detect various analytes in different matrices, has emerged. Biosensors indicate a biorecognition element with a physicochemical analyzer or detector, i.e., a transducer. In the present scenario, various types of biosensors have been deployed in healthcare and clinical research, for instance, biosensors for blood glucose monitoring. Pathogenic microbes are contributing mediators of numerous infectious diseases that are becoming extremely serious worldwide. The recent outbreak of COVID-19 is one of the most recent examples of such communal and deadly diseases. In efforts to work towards the efficacious treatment of pathogenic viral contagions, a fast and precise detection method is of the utmost importance in biomedical and healthcare sectors for early diagnostics and timely countermeasures. Among various available sensor systems, optical biosensors offer easy-to-use, fast, portable, handy, multiplexed, direct, real-time, and inexpensive diagnosis with the added advantages of specificity and sensitivity. Many progressive concepts and extremely multidisciplinary approaches, including microelectronics, microelectromechanical systems (MEMSs), nanotechnologies, molecular biology, and biotechnology with chemistry, are used to operate optical biosensors. A portable and handheld optical biosensing device would provide fast and reliable results for the identification and quantitation of pathogenic virus particles in each sample. In the modern day, the integration of intelligent nanomaterials in the developed devices provides much more sensitive and highly advanced sensors that may produce the results in no time and eventually help clinicians and doctors enormously. This review accentuates the existing challenges engaged in converting laboratory research to real-world device applications and optical diagnostics methods for virus infections. The review's background and progress are expected to be insightful to the researchers in the sensor field and facilitate the design and fabrication of optical sensors for life-threatening viruses with broader applicability to any desired pathogens.

C-reactive protein or procalcitonin combined with rhinorrhea for discrimination of viral from bacterial infections in hospitalized adults in non-intensive care units with lower respiratory tract infections

BACKGROUND

Whether procalcitonin (PCT) or C-reactive protein (CRP) combined with certain clinical characteristics can better distinguish viral from bacterial infections remains unclear. The aim of the study was to assess the ability of PCT or CRP combined with clinical characteristics to distinguish between viral and bacterial infections in hospitalized non-intensive care unit (ICU) adults with lower respiratory tract infection (LRTI).

METHODS

This was a post-hoc analysis of a randomized clinical trial previously conducted among LRTI patients. The ability of PCT, CRP and PCT or CRP combined with clinical symptoms to discriminate between viral and bacterial infection were assessed by portraying receiver operating characteristic (ROC) curves among patients with only a viral or a typical bacterial infection.

RESULTS

In total, 209 infected patients (viral 69%, bacterial 31%) were included in the study. When using CRP or PCT to discriminate between viral and bacterial LRTI, the optimal cut-off points were 22 mg/L and 0.18 ng/mL, respectively. When the optimal cut-off for CRP (≤ 22 mg/L) or PCT (≤ 0.18 ng/mL) combined with rhinorrhea was used to discriminate viral from bacterial LRTI, the AUCs were 0.81 (95% CI: 0.75-0.87) and 0.80 (95% CI: 0.74-0.86), which was statistically significantly better than when CRP or PCT used alone (p < 0.001). When CRP ≤ 22 mg/L, PCT ≤ 0.18 ng/mL and rhinorrhea were combined, the AUC was 0.86 (95% CI: 0.80-0.91), which was statistically significantly higher than when CRP (≤ 22 mg/L) or PCT (≤ 0.18 ng/mL) was combined with rhinorrhea (p = 0.011 and p = 0.021).

CONCLUSIONS

Either CRP ≤ 22 mg/L or PCT ≤ 0.18 ng/mL combined with rhinorrhea could help distinguish viral from bacterial infections in hospitalized non-ICU adults with LRTI. When rhinorrhea was combined together, discrimination ability was further improved.

Antibiotic Prescriptions Targeting Bacterial Respiratory Infections in Admitted Patients with COVID-19: A Prospective Observational Study

Introduction

Although bacterial co- and superinfections are rarely present in patients with COVID-19, overall antibiotic prescribing in admitted patients is high. In order to counter antibiotic overprescribing, antibiotic stewardship teams need reliable data concerning antibiotic prescribing in admitted patients with COVID-19.

Methods

In this prospective observational cohort study, we performed a quantitative and qualitative evaluation of antibiotic prescriptions in patients admitted to the COVID-19 ward of a 721-bed Belgian university hospital between 1 May and 2 November 2020. Data on demographics, clinical and microbiological parameters and antibiotic consumption were collected. Defined daily doses (DDD) were calculated for antibiotics prescribed in the context of a (presumed) bacterial respiratory tract infection and converted into two indicators: DDD/admission and DDD/100 hospital bed days. A team of infectious disease specialists performed an appropriateness evaluation for every prescription. A driver analysis was performed to identify factors increasing the odds of an antibiotic prescription in patients with a confirmed COVID-19 diagnosis.

Results

Of 403 eligible participants with a suspected COVID-19 infection, 281 were included. In 13.8% of the 203 admissions with a COVID-19 confirmed diagnosis, antibiotics were initiated for a (presumed) bacterial respiratory tract co-/superinfection (0.86 DDD/admission; 8.92 DDD/100 bed days; 39.4% were scored as ‘appropriate’). Five drivers of antibiotic prescribing were identified: history of cerebrovascular disease, high neutrophil/lymphocyte ratio in male patients, age, elevated ferritin levels and the collection of respiratory samples for bacteriological analysis.

Conclusion

In the studied population, the antibiotic consumption for a (presumed) bacterial respiratory tract co-/superinfection was low. In particular, the small total number of DDDs in patients with confirmed COVID-19 diagnosis suggests thoughtful antibiotic use. However, antibiotic stewardship programmes remain crucial to counter unnecessary and inappropriate antibiotic use in hospitalized patients with COVID-19.

Trial Registration

The study is registered at ClinicalTrials.gov (NCT04544072).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00535-2.

Novel Insights into the Role of Probiotics in Respiratory Infections, Allergies, Cancer, and Neurological Abnormalities

In recent years, probiotics have attracted public attention and transformed the social perception of microorganisms, convening a beneficial role/state on human health. With aging, the immune system, body physiology, and intestinal microbiota tend to change unfavorably, resulting in many chronic conditions. The immune-mediated disorders can be linked to intestinal dysbiosis, consequently leading to immune dysfunctions and a cluster of conditions such as asthma, autoimmune diseases, eczema, and various allergies. Probiotic bacteria such as Lactobacillus and Bifidobacterium species are considered probiotic species that have a great immunomodulatory and anti-allergic effect. Moreover, recent scientific and clinical data illustrate that probiotics can regulate the immune system, exert anti-viral and anti-tumoral activity, and shields the host against oxidative stress. Additionally, microbiota programming by probiotic bacteria can reduce and prevent the symptoms of respiratory infections and ameliorate the neurological status in humans. This review describes the most recent clinical findings, including safe probiotic therapies aiming to medicate respiratory infections, allergies, cancer, and neurological disorders due to their physiological interconnection. Subsequently, we will describe the major biological mechanism by which probiotic bacteriotherapy expresses its anti-viral, anti-allergic, anticancer, and neuro-stimulatory effects.

Salivary C-reactive protein-a possible predictor of serum levels in pediatric acute respiratory illness

Identifying the etiology of an acute respiratory infection in children is a well-known challenge. In this study, we evaluated the correlation between salivary C-reactive protein (CRP) and its serum counterpart, which is known to be higher in bacterial infections but necessitates a venipuncture. Salivary and serum CRPs were measured in children with an acute respiratory illness, aged 2 months to 18 years. Pearson's correlation coefficients were used to measure correlation. Discrimination of the salivary CRP levels for predicting serum levels above 100 mg/L was calculated and compared to serum CRP levels. Sensitivity and specificity were similarly calculated. Salivary CRP was measured in 104 samples. Levels correlated significantly and positively with serum CRP levels (r = 0.670, p<0.001). Area under the curve for predicting serum CRP levels of 100 mg/L was 0.848. For a salivary CRP concentration above 32,610 ng/L, the sensitivity and specificity were 69% and 93%, respectively, for accurately predicting a serum CRP level ≥100 mg/L.Conclusions: Salivary CRP can be used in the pediatric acute setting due to its high specificity for predicting elevated serum levels without the need for venipuncture. Further studies are required to achieve higher sensitivity rates. What is known: • Salivary C-reactive protein has shown correlation to its serum counterpart, mainly in healthy children, adults, and ill neonates. What is new: • In a large population of children with acute respiratory illness, aged 2 months to 18 years, salivary C-reactive protein showed high specificity for predicting elevated serum levels, thus indicating its potential as a diagnostic tool.

Nasopharyngeal density of respiratory viruses in childhood pneumonia in a highly vaccinated setting: findings from a case-control study

Background

Detection of pneumonia-causing respiratory viruses in the nasopharynx of asymptomatic children has made their actual contribution to pneumonia unclear. We compared nasopharyngeal viral density between children with and without pneumonia to understand if viral density could be used to diagnose pneumonia.

Methods

Nasopharyngeal swabs (NPS) were collected from hospitalised pneumonia cases at Princess Margaret Hospital (PMH) and contemporaneous age-matched controls at PMH outpatient clinics and a local immunisation clinic in Perth, Australia. The density (copies/mL) of respiratory syncytial virus (RSV), influenza A virus (InfA), human metapneumovirus (HMPV) and rhinovirus in NPS was determined using quantitative PCR. Linear regression analysis was done to assess the trend between viral density and age in months. The association between viral density and disease status was examined using logistic regression. Area under receiver operating characteristic (AUROC) curves were assessed to determine optimal discriminatory viral density cut-offs.

Results

Through May 2015 to October 2017, 230 pneumonia cases and 230 controls were enrolled. Median nasopharyngeal density for any respiratory virus was not substantially higher in cases than controls (p>0.05 for each). A decreasing density trend with increasing age was observed—the trend was statistically significant for RSV (regression coefficient −0.04, p=0.004) but not for other viruses. After adjusting for demographics and other viral densities, for every log₁₀ copies/mL density increase, the odds of being a case increased by six times for RSV, three times for HMPV and two times for InfA. The AUROC curves were <0.70 for each virus, suggesting poor case–control discrimination based on viral density.

Conclusion

The nasopharyngeal density of respiratory viruses was not significantly higher in children with pneumonia than those without; however, the odds of being a case increased with increased density for some viruses. The utility of viral density, alone, in defining pneumonia was limited.

Novel point-of-care biomarker combination tests to differentiate acute bacterial from viral respiratory tract infections to guide antibiotic prescribing: a systematic review

BACKGROUND

Acute respiratory tract infections (RTIs) are the most common reason to seek medical care, with many patients receiving inappropriate antibiotics. Novel testing approaches to identify aetiology at the point-of-care are required to accurately guide antibiotic treatment.

OBJECTIVE

To assess the diagnostic accuracy of biomarker combinations to rapidly differentiate between acute bacterial or viral RTI aetiology.

DATA SOURCES

MEDLINE, Embase and Web of Science databases were searched to February 2021.

STUDY ELIGIBILITY CRITERIA

Diagnostic accuracy studies comparing accuracy of point-of-care and rapid diagnostic tests in primary or secondary care, consisting of biomarker combinations, to identify bacterial or viral aetiology of RTI.

METHODS

Risk of bias was assessed using the QUADAS-2 tool. Sensitivity and specificity of tests reported by more than one study were meta-analysed using a random effects model.

RESULTS

Twenty observational studies (3514 patients) were identified. Eighteen were judged at high risk of bias. For bacterial aetiologies, sensitivity ranged from 61% to 100% and specificity from 18% to 96%. For viral aetiologies, sensitivity ranged from 59% to 97% and specificity from 74% to 100%. Studies evaluating two commercial tests were meta-analysed. For ImmunoXpert, the summary sensitivity and specificity were 85% (95% CI 75%-91%, k = 4) and 86% (95% CI 73%-93%, k = 4) for bacterial infections, and 90% (95% CI 79%-96%, k = 3) and 92% (95% CI 83%-96%, k = 3) for viral infections, respectively. FebriDx had pooled sensitivity and specificity of 84% (95% CI 75%-90%, k = 4) and 93% (95% CI 90%-95%, k = 4) for bacterial infections, and 87% (95% CI 72%-95%; k = 4) and 82% (95% CI 66%-86%, k = 4) for viral infections, respectively.

CONCLUSION

Combinations of biomarkers show potential clinical utility in discriminating the aetiology of RTIs. However, the limitations in the evidence base, due to a high proportion of studies with high risk of bias, preclude firm conclusions. Future research should be in primary care and evaluate patient outcomes and cost-effectiveness with experimental study designs.

CLINICAL TRIAL

PROSPERO registration number: CRD42020178973.

Performance of Diagnostic Model for Differentiating Between COVID-19 and Influenza: A 2-Center Retrospective Study

Background

COVID-19 and influenza share many similarities, such as mode of transmission and clinical symptoms. Failure to distinguish the 2 diseases may increase the risk of transmission. A fast and convenient differential diagnosis between COVID-19 and influenza has significant clinical value, especially for low- and middle-income countries with a shortage of nucleic acid detection kits. We aimed to establish a diagnostic model to differentiate COVID-19 and influenza based on clinical data.

Material/Methods

A total of 493 patients were enrolled in the study, including 282 with COVID-19 and 211 with influenza. All data were collected and reviewed retrospectively. The clinical and laboratory characteristics of all patients were analyzed and compared. We then randomly divided all patients into development sets and validation sets to establish a diagnostic model using multivariate logistic regression analysis. Finally, we validated the diagnostic model using the validation set.

Results

We preliminarily established a diagnostic model for differentiating COVID-19 from influenza that consisted of 5 variables: age, dry cough, fever, white cell count, and D-dimer. The model showed good performance for differential diagnosis.

Conclusions

This initial model including clinical features and laboratory indices effectively differentiated COVID-19 from influenza. Patients with a high score were at a high risk of having COVID-19, while patients with a low score were at a high risk of having influenza. This model could help clinicians quickly identify and isolate cases in the absence of nucleic acid tests, especially during the cocirculation of COVID-19 and influenza. Owing to the study’s retrospective nature, further prospective study is needed to validate the accuracy of the model.

Alterations in biochemical markers in adenovirus infection

BACKGROUND

Analyze possible relationships between HAdV and markers for inflammation, specifically the C-reactive protein (CRP) and procalcitonin (PCT) tests, along with other haematological markers.

METHODS

Retrospective study of 487 children presenting with fever and/or acute respiratory symptoms in the Paediatric Emergency Department. Analyses included viral presence/absence (both HAdV and other respiratory viruses) in respiratory exudates, CRP and PCT alterations in plasma, and haematological markers in whole blood.

RESULTS

Viral load was >500 copies/10³ cells of HAdV in 127 cases (26.1%), of which 66 (52%, P<0.0001) had alterations in PCT, and 112 (88.1%, P<0.0001) in CRP. Haematological markers were similar either HAdV was present or not, although many HAdV positive patients demonstrated leukocytosis (66%). Bacterial cultures from 141 samples showed altered PCT in 27 (60%) with HAdV infection, in 3 (18.7%) with bacterial infection, and 13 (26.5%) without either viral or bacterial infection (P<0.05). CRP was altered in 88.9% of HAdV infected children and in 87% infected with bacteria, although the percentage was greater than in cases where other respiratory viruses were present (61.3% P<0.05).

CONCLUSIONS

Results demonstrate a clear relationship between HAdV infection and alterations in PCT and CRP which should be taken into account in paediatric patient management.

Pneumonia

Pneumonia is a common acute respiratory infection that affects the alveoli and distal airways; it is a major health problem and associated with high morbidity and short-term and long-term mortality in all age groups worldwide. Pneumonia is broadly divided into community-acquired pneumonia or hospital-acquired pneumonia. A large variety of microorganisms can cause pneumonia, including bacteria, respiratory viruses and fungi, and there are great geographical variations in their prevalence. Pneumonia occurs more commonly in susceptible individuals, including children of <5 years of age and older adults with prior chronic conditions. Development of the disease largely depends on the host immune response, with pathogen characteristics having a less prominent role. Individuals with pneumonia often present with respiratory and systemic symptoms, and diagnosis is based on both clinical presentation and radiological findings. It is crucial to identify the causative pathogens, as delayed and inadequate antimicrobial therapy can lead to poor outcomes. New antibiotic and non-antibiotic therapies, in addition to rapid and accurate diagnostic tests that can detect pathogens and antibiotic resistance will improve the management of pneumonia.

Distinguishing bacterial versus non-bacterial causes of febrile illness - A systematic review of host biomarkers

BACKGROUND

Acute febrile illnesses (AFIs) represent a major disease burden globally; however, the paucity of reliable, rapid point-of-care testing makes their diagnosis difficult. A simple tool for distinguishing bacterial versus non-bacterial infections would radically improve patient management and reduce indiscriminate antibiotic use. Diagnostic tests based on host biomarkers can play an important role here, and a target product profile (TPP) was developed to guide development.

OBJECTIVES

To qualitatively evaluate host biomarkers that can distinguish bacterial from non-bacterial causes of AFI.

DATA SOURCES

The PubMed database was systematically searched for relevant studies published between 2015 and 2019.

STUDY ELIGIBILITY CRITERIA

Studies comparing diagnostic performances of host biomarkers in patients with bacterial versus non-bacterial infections were included.

PARTICIPANTS

Studies involving human participants and/or human samples were included.

METHODS

We collected information following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A risk of bias assessment was performed, based on a modified QUADAS-2 (Quality Assessment of Diagnostic Accuracy Score 2).

RESULTS

We identified 1107 publications. Following screening, 55 publications were included, with 265 biomarker entries. Entries mostly comprised protein biomarkers (58.9%), followed by haematological, RNA, and metabolite biomarkers (15.5%, 8.7%, 12.5%). Sensitivity/specificity was reported for 45.7% of biomarker entries. We assessed a high overall risk of bias for most entries (75.8%). In studies with low/medium risk of bias, four biomarker entries tested in blood samples had sensitivity/specificity of more than 0.90/0.80. Only 12 additional biomarker entries were identified with sensitivity/specificity of more than 0.65/0.65.

CONCLUSIONS

Most recently assessed biomarkers represent well-known biomarkers, e.g. C-reactive protein and procalcitonin. Some protein biomarkers with the highest reported performances include a combined biomarker signature (CRP, IP-10, and TRAIL) and human neutrophil lipocalin (HNL). Few new biomarkers are in the pipeline; however, some RNA signatures show promise. Further high-quality studies are needed to confirm these findings.

Decoding the Mechanism of Huanglian Jiedu Decoction in Treating Pneumonia Based on Network Pharmacology and Molecular Docking

Huang-Lian-Jie-Du decoction (HLJDD) has been used to treat pneumonia for thousands of years in China. However, our understanding of its mechanisms on treating pneumonia is still unclear. In the present work, network pharmacology was used to analyze the potential active ingredients and molecular mechanisms of HLJDD on treating pneumonia. A total of 102 active ingredients were identified from HLJDD, among which 54 were hit by the 69 targets associated with pneumonia. By performing Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, we obtained the main pathways associated with pneumonia and those associated with the mechanism of HLJDD in the treatment of pneumonia. By constructing the protein-protein interaction network of common targets, 10 hub genes were identified, which were mainly involved in the tumor necrosis factor (TNF) signaling pathway, interleukin 17 (IL-17) signaling pathway, and nucleotide-binding oligomerization domain (NOD)-like receptor signaling pathway. Moreover, the results of molecular docking showed that the active ingredients of HLJDD had a good affinity with the hub genes. The final results indicate that HLJDD has a greater effect on bacterial pneumonia than on viral pneumonia. The therapeutic effect is mainly achieved by regulating the host immune inflammatory response and oxidative stress reaction, antibacterial microorganisms, alleviating the clinical symptoms of pneumonia, repairing damaged cells, and inhibiting cell migration.

Viral respiratory infections: a cause of community-acquired pneumonia or a predisposing factor?

PURPOSE OF REVIEW

A cause for community-acquired pneumonia (CAP) is only identified in ∼50% of cases. Nasopharyngeal PCR panels contain more viruses than previously. The problem then becomes determining the relevance of the organisms identified rather than figuring out which virus is present. This review addresses how to distinguish between viral CAP and bacterial CAP, how viral CAP predisposes to bacterial CAP and some novel antiviral treatment being conducted.

RECENT FINDINGS

The pneumonia severity index has been studied in patients with viral CAP. There are new studies using biomarkers to help determine when antimicrobial treatment is needed in CAP patients, and there is still no consensus. Newer devices are being invented in an effort to separate upper from lower respiratory organisms to make test results more relevant. Several outcome studies in patients with viral CAP are reviewed.

SUMMARY

In addition to clinical correlation, using biomarkers can be useful to distinguish viral from bacterial CAP. Outcomes in patients with a co-infection are generally worse as a viral infection may predispose someone to a bacterial pneumonia. Influenza CAP treatment may be initially accompanied with antimicrobials until a patient's diagnosis is clear (∼48-72 h). Future research is being conducted for antiviral treatment more than for influenza.

Differential Markers of Bacterial and Viral Infections in Children for Point-of-Care Testing

Children suffering from infectious diseases, both bacterial and viral, are often treated with empirical antibiotics. Keeping in mind both the menace of microorganisms and antibiotic toxicity, it is imperative to develop point-of-care testing (POCT) to discriminate bacterial from viral infections, and to define indications for antibiotic treatment. This article reviews potential protein biomarkers and host-derived gene expression signatures for differentiating between bacterial and viral infections in children, and focuses on emerging multiplex POCT devices for the simultaneous detection of sets of protein biomarkers or streamlined gene expression signatures that may provide rapid and cost-effective pathogen-discriminating tools.

Bacteria and viruses activate or inhibit different signaling pathways in the cells they infect, and further give rise to different host transcriptional signatures as well as to unique protein biomarkers.

Many of the newly evaluated protein biomarkers, especially in combination, have better discriminative value for distinguishing between bacterial and viral infections than the biomarkers that are currently used for examining infections in children.

The transcriptomes of children undergo remarkable changes when they are infected by different types of bacteria and viruses. Approaches based on host-derived DNA/RNA signatures can accurately discriminate bacterial from viral infections.

Emerging multiplex POCT techniques allow simultaneous testing of protein- or gene-based biomarkers in an outpatient setting.

Age-dependent changes of total and differential white blood cell counts in children

BACKGROUND

Total and differential white blood cell counts are important for the diagnostic evaluation of suspected diseases. To facilitate the interpretation of total and differential white blood cell counts in pediatric patients, the present study investigated age-dependent changes in total and differential white blood cell counts in healthy reference children.

METHODS

Data were obtained from the Pediatric Reference Intervals in China study (PRINCE), which aims to establish and verify pediatric reference intervals for Chinese children based on a nationwide multicenter cross-sectional study from January 2017 to December 2018. Quantile curves were calculated using the generalized additive models for location, shape, and scale method. The 2.5th, 50th, and 97.5th quantile curves were calculated for both total and differential white blood counts. Percents of stacked area charts were used to demonstrate the proportions of differential white blood cells. All statistical analyses were performed using R software.

RESULTS

Both 50th and 97.5th quantiles of total white blood cell count and monocyte count were highest at birth, then rapidly decreased in the first 6 months of life; relatively slow reduction continued until 2 years of age. The lymphocyte count was low during infancy and increased to its highest level at 6 months of age; it then exhibited moderate and continuous reduction until approximately 9 years of age. The pattern of neutrophil count changed with age in a manner opposite to that of lymphocyte count. Besides, there were two inter-sections of lymphocyte count and neutrophil count during infancy and at approximately 5 years of age, based on locally weighted regression (LOESS) analysis. There were no apparent age-related changes in eosinophil or basophil counts.

CONCLUSION

These data regarding age-related changes in total and differential white blood cell counts can be used to assess the health of pediatric patients and guide clinical decisions.

Dysregulation of angiopoietin-Tie-2 axis in ugandan children hospitalized with pneumonia

OBJECTIVE

Pneumonia is the leading cause of death in children under 5, with the highest burden in resource-limited countries. Endothelial activation occurs in pneumonia and can be assessed using quantitative levels of biomarkers angiopoietin (Ang)-1 and Ang-2. We examined admission levels of Ang-1 and Ang-2 in pediatric pneumonia and their association with disease severity and outcome.

METHODS

Prospective cohort study of children with hypoxemic pneumonia admitted to two hospitals in Uganda. Clinical, radiographic, and microbiologic characteristics were measured at admission. Disease severity was assessed using the Respiratory Index of Severity in Children (RISC). Plasma levels of Ang-1 and Ang-2 were quantified by enzyme-linked immunosorbent assay. Vital signs, oxygen supplementation, and mortality were assessed prospectively.

RESULTS

We included 65 patients (43% female) with median age 19 months (IQR 8-24). Admission Ang-2/Ang-1 ratio directly correlated with RISC (ρ = 0.32, p = 0.008) and lactate level (ρ = 0.48, p < 0.001). Ang-2/Ang-1 ratio was higher in pneumococcal pneumonia than viral RTI (0.19 [IQR: 0.076-0.54] vs. 0.078 [IQR: 0.027-0.11]; p = 0.03). Elevated Ang-2/Ang-1 ratio (>0.084) was associated with prolonged tachypnea (HR 0.50 (95%CI 0.29-0.87), p = 0.02), fever (HR 0.56 (95%CI 0.33 to 0.96), p = 0.02), longer duration of oxygen therapy (HR 0.59 (95%CI 0.35-0.99), p = 0.04), and hospital stay (HR 0.43 (95%CI 0.25-0.74), p = 0.001). The Ang-2/Ang-1 ratio at admission was higher in fatal cases relative to survivors (0.36 [IQR: 0.17-0.58] vs. 0.077 [IQR: 0.025-0.19]; p = 0.05) CONCLUSION: Endothelial activation in hypoxemic pediatric pneumonia, reflected by high plasma Ang-2/Ang-1 ratio, is associated with disease severity, prolonged recovery time, and mortality.

Antibodies against atypical pathogens and respiratory viruses detected by Pneumoslide IgM test in adults with community-acquired pneumonia in Guangzhou City

Background

To detect the serum antibodies against respiratory viruses and atypical pathogens in adults with community‐acquired pneumonia (CAP) in Guangzhou City (Guangdong province, China).

Methods

A retrospective study was carried out with samples from 685 adults who were admitted with CAP and 108 non‐CAP control patients. Atypical pathogens and respiratory viruses in serum were detected using the Pneumoslide IgM test from Vircell, Spain. All patients were divided into 6 groups according to age: 18‐24, 25‐44, 45‐59, 60‐74, 75‐89, and >90.

Results

The total positive rate of CAP was 35.4%, which was highest in the 18‐24 age group (P < .05). The highest positive rate, 17.11%, was observed for Mycoplasma pneumoniae (MP). The mean age of MP‐infected patients was higher than that of the controls (P < .05). The positive rates for influenza B (INFB), Legionella pneumophila (LP1), Coxiella burnetii (COX), influenza A (INFA), parainfluenza virus (PIV), respiratory syncytial virus (RSV), Chlamydophila pneumoniae (CP), and adenovirus (ADV) were 5.56%, 3.07%, 2.63%, 2.34%, 1.90%, 1.61, 0.88%, and 0.29%, respectively. There were 4.37% of patients with CAP having multiple infections. The main symptoms observed in the 685 CAP patients were cough and sputum production, in 78.4% and 67.4%. Fever was followed by 54% of CAP patients. Dyspnea (39.1%), anorexia (36.8%), increased thirst (26.7%), chills (18.7), headache (14.6%), and nausea (13.1%) were also frequently observed in the CAP patients.

Conclusions

MP infection was the most common in adult CAP patients in Guangzhou City with the highest positive rate in the 18‐24 age groups.

Community‐acquired pneumonia among children: the latest evidence for an updated management

Objetivo

Fonte de dados

Síntese dos dados

Conclusões

Community-acquired pneumonia among children: the latest evidence for an updated management

OBJECTIVE

To provide cutting-edge information for the management of community-acquired pneumonia in children under 5 years, based on the latest evidence published in the literature.

DATA SOURCE

A comprehensive search was conducted in PubMed, by using the expressions: "community-acquired pneumonia" AND "child" AND "etiology" OR "diagnosis" OR "severity" OR "antibiotic". All articles retrieved had the title and the abstract read, when the papers reporting the latest evidence on each subject were identified and downloaded for complete reading.

DATA SYNTHESIS

In the era of largely implemented bacterial conjugate vaccines and widespread use of amplification nucleic acid techniques, respiratory viruses have been identified as the most frequent causative agents of community-acquired pneumonia in patients under 5 years. Hypoxemia (oxygen saturation ≤96%) and increased work of breathing are signs most associated with community-acquired pneumonia. Wheezing detected on physical examination independently predicts viral infection and the negative predictive value (95% confidence interval) of normal chest X-ray and serum procalcitonin <0.25ng/dL was 92% (77-98%) and 93% (90-99%), respectively. Inability to drink/feed, vomiting everything, convulsions, lower chest indrawing, central cyanosis, lethargy, nasal flaring, grunting, head nodding, and oxygen saturation <90% are predictors of death and can be used as indicators for hospitalization. Moderate/large pleural effusions and multilobar infiltrates are predictors of severe disease. Orally administered amoxicillin is the first line outpatient treatment, while ampicillin, aqueous penicillin G, or amoxicillin (initiated initially by intravenous route) are the first line options to treat inpatients.

CONCLUSIONS

Distinct aspects of childhood community-acquired pneumonia have changed during the last three decades.

Blood biomarkers differentiating viral versus bacterial pneumonia aetiology: a literature review

Background and objectives

The goal of this literature review is to compare current studies regarding the accuracy of different serum markers in differentiating viral from bacterial pneumonia in the pediatric population with what is employed in the medical settings at present. Currently there is still a lack of significant research, that would give us evaluation on biomarkers benefits towards getting a definite diagnosis of pneumonia. Finding out the potential of biomarkers to differentiate between viral and bacterial pneumonia is also important because knowing the exact pathogen would prevent irrational use of antibiotics. At present, irrational, broad-spectrum antibiotic use and increasing antibiotic resistance in microorganisms are still one of the greatest challenges in clinical settings. The use of biomarkers in clinical practice would not only facilitate accurate diagnosis, but would also help to reduce the amount of antibiotics overuse.

Materials and methods

Literature search conducted on Medline and Google Scholar using a combination of terms. Articles that were in English and within ten years of the search date were manually sorted according to inclusion and exclusion criteria. Results: Initial search returned n = 13,408. After activating filters, n = 140 were identified of which n = 12 included for literature review.

Conclusions

Rise or drop in the concentration of a single marker is not accurate enough for predicting viral/bacterial community acquired pneumonia. This is because there is overlapping to a varying extent depending on the marker cut-off values, detection methods, analyses, the desired specificity, and sensitivity. Furthermore, the presence of mixed infection makes almost all markers suboptimal to be used universally. New markers such as MxA1 and HMGB1 gave promising results. However, to replicate a similar testing condition in a clinical environment may not be practical. Another approach is to make use of more than one marker and combine with clinical signs and symptoms. This may not be cost-effective in many clinical settings; nevertheless, in many studies, marker combination greatly improved the predictive power.

Biosensors for detecting viral and bacterial infections using host biomarkers: a review

A schematic diagram showing multiple modes of biosensing platforms for the diagnosis of bacterial or viral infections.

PedCAPNETZ - prospective observational study on community acquired pneumonia in children and adolescents

Background

Pediatric community acquired pneumonia (pedCAP) is one of the leading causes for childhood morbidity accounting for up to 20% of pediatric hospital admissions in high income countries. In spite of its high morbidity, updated epidemiological and pathogen data after introduction of preventive vaccination and novel pathogen screening strategies are limited. Moreover, there is a need for validated recommendations on diagnostic and treatment regimens in pedCAP. Through collection of patient data and analysis of pathogen and host factors in a large sample of unselected pedCAP patients in Germany, we aim to address and substantially improve this situation.

Methods

pedCAPNETZ is an observational, multi-center study on pedCAP. Thus far, nine study centers in hospitals, outpatient clinics and practices have been initiated and more than 400 patients with radiologically confirmed pneumonia have been enrolled, aiming at a total of 1000 study participants. Employing an online data base, information on disease course, treatment as well as demographical and socioeconomical data is recorded. Patients are followed up until day 90 after enrollment; Comprehensive biosample collection and a central pedCAPNETZ biobank allow for in-depth analyses of pathogen and host factors. Standardized workflows to assure sample logistics and data management in more than fifteen future study centers have been established.

Discussion

Through comprehensive epidemiological, clinical and biological analyses, pedCAPNETZ fills an important gap in pediatric and infection research. To secure dissemination of the registry, we will raise clinical and scientific awareness at all levels. We aim at participating in decision making processes for guidelines and prevention strategies. Ultimately, we hope the results of the pedCAPNETZ registry will help to improve care and quality of life in pedCAP patients in the future.