Etiology Of Pneumonia Research Articles

Autoantibodies targeting interferons and GM-CSF are associated with adverse outcome risk, comorbidities, and pathogen in community-acquired pneumonia.

Cytokine autoantibodies (c-aAb) have been associated with pulmonary diseases, including severe novel coronavirus disease 2019 (COVID-19) and pulmonary alveolar proteinosis. This study aimed to determine c-aAb association with community-acquired pneumonia (CAP) etiology (SARS-CoV-2, influenza, or bacteria) and c-aAb associations with CAP-related clinical outcomes and pulmonary comorbidities. In a cohort of 665 patients hospitalized with CAP, c-aAb targeting interferon α (IFNα), IFNβ, IFNγ, interleukin-1α (IL-1α), IL-6, IL-10, and granulocyte-macrophage colony-stimulating factor (GM-CSF) were measured in plasma samples. Associations between c-aAb and baseline characteristics, pulmonary comorbidities, pathogen, intensive care unit (ICU) transferal, time to clinical stability, and mortality were estimated, with results stratified by sex. More men infected with SARS-CoV-2 were had high-titer type 1 IFN c-aAb compared to other pathogens. Among patients with CAP, asthma and bronchiectasis comorbidities were associated with high-titer GM-CSF c-aAb in men, and men with high-titer IFNβ c-aAb had increased odds for ICU transferal. High-titer IL-10 c-aAb were associated with faster clinical stability in women. In men with CAP, various c-aAb-including type 1 IFN and GM-CSF c-aAb-were associated with adverse clinical events and comorbidities, whereas c-aAb targeting an autoinflammatory cytokine were associated with a positive outcome in women. This suggests that the potentially immunomodulatory effects of c-aAb depend on pathogen, autoantibody specificity, comorbidity, and sex.

Clinical and etiological characteristics and cytokine profile in school-age children with community-acquired pneumonia

The urgent task of modern pediatrics is the study of the etiology and pathophysiology of community-acquired pneumonia in school-aged children due to difficulties in diagnosis and treatment, as well as the high risk of life-threatening complications and death.Purpose. To investigate the activity of pro-inflammatory and anti-inflammatory responses as measured by cytokine levels in the peripheral blood of children with community-acquired pneumococcal and non-pneumococcal pneumonia.Material and methods. The etiology of community-acquired pneumonia was confirmed by comparing the results of rapid testing of pneumococcus in urine and data from traditional bacteriological methods. The study included 118 children (57 boys and 61 girls) aged 7 to 16 years with various morphological variants of community-acquired pneumonia, which were divided into 2 groups. The first group included 28 children with pneumococcal etiology of community-acquired pneumonia, and the second group included 90 patients with non-pneumococcal community-acquired pneumonia. Levels of interleukins IL-1, IL-4, IL-8 and TNF-α were determined in all children by enzyme immunoassays.Results. In the etiology of community-acquired pneumonia in school-age children, atypical pathogens are responsible for more than 50% of cases. The clinical effectiveness of rapid testing of pneumococcal antigens in urine has been shown, and their use in routine pediatric practice has made it possible to timely identify a group of severe community-acquired pneumonia and reasonably prescribe antibacterial medications. It has been demonstrated that pneumococcal-induced pneumonia is characterized by higher levels of proinflammatory cytokines. These levels, along with the clinical course of the disease, confirm the high level of systemic inflammation. Relatively lower levels of proinflammatory cytokines corresponded to a more mild clinical picture of community-acquired pneumonia of non-pneumococcal etiology, which on the one hand may reflect a relatively «balanced» inflammatory response, and on the other hand determine the protracted and polyclinic course of the infectious process.Conclusion. The etiology of community-acquired pneumonia in school-age children is dominated by atypical pathogens. Community-acquired pneumonia of pneumococcal etiology has more severe clinical courses, and their early identification will allow for the appropriate prescription of initial antibacterial treatment.

Clinical and Epidemiologic Features of Mycoplasma pneumoniae Infection Among Adults Hospitalized with Community-acquired Pneumonia.

Background/Purpose: The burden and epidemiology of Mycoplasma pneumoniae (Mp) community-acquired pneumonia (CAP) among hospitalized U. S. adults (≥ 18 years) are poorly understood. Methods: In the Etiology of Pneumonia in the Community (EPIC) study, we prospectively enrolled 2272 adults hospitalized with radiographically-confirmed pneumonia between January 2010-June 2012 and tested nasopharyngeal/oropharyngeal swabs for Mp by real-time polymerase chain reaction (PCR). Clinical and epidemiological features of Mp-PCR-positive and -negative adults were compared using logistic regression. Macrolide susceptibility was assessed by genotyping isolates. Results: Among 2272 adults, 43 (1.8%) were Mp-PCR-positive (median age: 45 years); 52% were male, and 56% were non-Hispanic white. Only one patient had Mp macrolide resistance. Four (9%) were admitted to the intensive care unit (ICU). No in-hospital deaths were reported. Of the 9 (21%) who received an outpatient antibiotic ≤5 days pre-admission, 2 (22%) received an antibiotic with Mp activity. Variables significantly associated with higher odds of Mp detection included age {18-29 years [(adjusted odds ratio (aOR): 11.7 (95% confidence interval (CI): 5.1- 26.6) versus ≥50 years]} and radiographic lymphadenopathy [aOR: 3.5 (95% CI: 1.2- 9.3)]. Conclusions: M. pneumoniae, commonly known to cause "walking pneumonia", was detected among hospitalized adults, with the highest prevalence among young adults. Although associated with clinically non-specific symptoms, approximately one out of every ten patients were admitted to the ICU. Increasing access to M. pneumoniae point-of-care testing could facilitate targeted treatment and avoid hospitalization.

On the issue of the etiology of community-acquired pneumonia in children

According to global statistics, the number of cases of community-acquired pneumonia in children exceeds 150 million per year, and despite the introduction of vaccinations, this figure has not significantly decreased. Respiratory viruses, particularly respiratory syncytial virus, are recognized as the main cause of community-acquired pneumonia among preschool children during non-epidemic periods. Pneumococci also continue to play a significant role among bacterial pathogens. There is a significant increase in the prevalence of M. pneumoniae in the etiological structure of community-acquired pneumonia in recent years. Modern clinical guidelines for the use of antibiotics recommend taking into account patient age, vaccination status, and data on circulating pneumococcal strains when prescribing treatment. The COVID-19 pandemic and its subsequent relaxation of strict restrictions in the last two years have led to changes in the structure of infectious diseases, including the causes of lower respiratory tract infections.

Prevalence and etiology of ventilator-associated pneumonia during the COVID-19 pandemic in Denmark: Wave-dependent lessons learned from a mixed-ICU.

Ventilator-associated pneumonia (VAP) may be a particular concern in patients with severe coronavirus disease 2019 (COVID-19). We aimed to determine the prevalence and etiology of VAP in critically ill COVID-19 patients in a Danish intensive care unit (ICU) during the first three waves of the COVID-19 pandemic and to study associations between dexamethasone (DXM) use and development of VAP. In an observational single-center study patients were retrospectively screened for VAP including causative pathogens, use of DXM and commonly used antibiotics. Diagnosis of VAP required invasive mechanical ventilation (IMV) >48 h with presence of a new bacterial agent and clinical signs of infection. For analysis, common descriptive statistics were applied. Cox proportional hazards models were used to analyze the association between DXM use and VAP. VAP was detected in 53/119 (44.5%) mechanically ventilated patients across all three COVID-19 waves. Median length of IMV for VAP patients was 24 [15-41] days, and 3 out of 4 were males. VAP was most prevalent (47.0%) during the second wave. Common pathogens included Klebsiella pneumoniae (24.5%), Enterobacter aerogenes (17.0%) and Pseudomonas aeruginosa (13.2%), Staphylococcus aureus (13.2%), and Escherichia coli (13.2%). A change from Gram-negative bacteria only to a combination of Gram-positive and Gram-negative bacteria was observed in the second wave compared to first. Use of DXM was not associated with VAP (adjusted hazard ratio 1.63 95% CI: 0.84-3.17). The prevalence of VAP was high across all three COVID-19 waves and showed a different distribution of pathogens between the first and second wave. Use of DXM was not associated with VAP development. Further and larger studies are needed to understand the risk factors associated with VAP in patients with COVID-19.

Epidemiology of human metapneumovirus among children with severe or very severe pneumonia in high pneumonia burden settings: the Pneumonia Etiology Research for Child Health (PERCH) study experience

ObjectivesAfter respiratory syncytial virus (RSV), human metapneumovirus (hMPV) was the second-ranked pathogen attributed to severe pneumonia in the PERCH study. We sought to characterize hMPV-positive cases in high-burden settings, which have limited data, by comparing with RSV-positive and other cases. MethodsChildren aged 1–59 months hospitalized with suspected severe pneumonia and age/season-matched community controls in seven African and Asian countries had nasopharyngeal/oropharyngeal swabs tested by multiplex PCR for 32 respiratory pathogens, among other clinical and lab assessments at admission. Odds ratios adjusted for age and site (adjusted OR [aOR]) were calculated using logistic regression. Aetiologic probability was estimated using Bayesian nested partial latent class analysis. Latent class analysis identified syndromic constellations of clinical characteristics. ResultshMPV was detected more frequently among cases (267/3887, 6.9%) than controls (115/4976, 2.3%), among cases with pneumonia chest X-ray findings (8.5%) than without (5.5%), and among controls with respiratory tract illness (3.8%) than without (1.8%; all p ≤ 0.001). HMPV-positive cases were negatively associated with the detection of other viruses (aOR, 0.18), especially RSV (aOR, 0.11; all p < 0.0001), and positively associated with the detection of bacteria (aORs, 1.77; p 0.03). No single clinical syndrome distinguished hMPV-positive from other cases. Among hMPV-positive cases, 65.2% were aged <1 year and 27.5% had pneumonia danger signs; positive predictive value for hMPV aetiology was 74.5%; mortality was 3.9%, similar to RSV-positive (2.4%) and lower than that among other cases (9.6%). DiscussionHMPV-associated severe paediatric pneumonia in high-burden settings was predominantly in young infants and clinically indistinguishable from RSV. HMPV-positives had low case fatality, similar to that in RSV-positives.

The protective effect and immunomodulatory ability of orally administrated Lacticaseibacillus rhamnosus GG against Mycoplasma pneumoniae infection in BALB/c mice.

Mycoplasma pneumoniae represents one of the significant etiologies of community-acquired pneumonia in pediatric patients. However, clinical treatment of M. pneumoniae infection in children has encountered challenges due to the escalating resistance to quinolones. Numerous studies have highlighted the potential of probiotic lactobacillus administration in boosting immune responses to bacterial and viral respiratory infections. In this study, the protective efficacy of pre-oral administration of Lacticaseibacillus rhamnosus GG (LGG), Limosilactobacillus reuteri F275, Lactiplantibacillus plantarum NCIMB 8826, L. plantarum S1 or L. plantarum S2 was evaluated in the BALB/c mice model; it was observed that among these five strains of lactobacillus, the supplementation of LGG exhibited the most significant protective effect against M. pneumoniae infection. Moreover, when administered orally, both live LGG and heat-inactivated LGG have demonstrated efficacy in reducing the burden of M. pneumoniae in the lungs and alleviating pulmonary inflammation. Oral supplementation with LGG resulted in the inhibition of neutrophil recruitment into the lungs and increased recruitment of alveolar macrophages in M. pneumoniae-infected mice. Additionally, LGG supplementation led to increased production of IL-10 and secretory IgA (sIgA), while suppressing the levels of IL-1β, IL-6, IL-17A, and TNF-α in the lungs of mice infected with M. pneumoniae. The data suggests that supplementation with LGG can modulate immune responses, decrease pathogen load, and alleviate inflammatory injury in the lungs of M. pneumoniae-infected mice.

Transcriptomic Biomarkers Associated with Microbiological Etiology and Disease Severity in Childhood Pneumonia.

Challenges remain in discerning microbiologic etiology and disease severity in childhood pneumonia. Defining host transcriptomic profiles during illness may facilitate improved diagnostic and prognostic approaches. Using whole blood ribonucleic acid sequencing from 222 hospitalized children with radiographic pneumonia and 45 age-matched controls, we identified differentially expressed genes that best identified children according to detected microbial pathogens (viral-only vs. bacterial-only and typical vs. atypical bacterial [+/- viral co-detection]) and an ordinal measure of phenotypic severity (moderate, severe, very severe). Overall, 135 (61%) children had viral-only detections, 15 (7%) had typical bacterial (+/- viral co-detections), and 26 (12%) had atypical bacterial (+/- viral co-detections). Eleven DE genes distinguished between viral-only and bacterial-only detections. Sixteen DE genes distinguished between atypical and typical bacterial detections (+/- viral co-detections). Nineteen DE genes distinguished between levels of pneumonia severity, including four genes also identified in the viral-only vs. bacterial-only model (IGHGP, PI3, CD177, RAP1GAP1) and four genes from the typical vs atypical bacterial model (PRSS23, IFI27, OLFM4, and ABO). We identified transcriptomic biomarkers associated with microbial detections and phenotypic severity in children hospitalized with pneumonia. These DE genes are promising candidates for validation and translation into diagnostic and prognostic tools.

Characterization of Extraintestinal Pathogenic Escherichia coli Strains Causing Canine Pneumonia in China: Antibiotic Resistance, Virulence Genes, and Sequence Typing.

To determine the etiological agents responsible for acute pneumonia in puppies in China, this study utilized bronchoalveolar lavage (BAL) fluid extraction to enable the isolation, culture, biochemical identification, and 16S rRNA PCR amplification of the pathogens. Following preliminary identification, the pathogens underwent analysis for antibiotic resistance phenotypes and resistance genes. Additionally, the study examined the presence of virulence genes, conducted multilocus sequence typing (MLST), and performed whole-genome sequencing (WGS). The findings revealed that all four isolated pathogens were characterized as extraintestinal pathogenic Escherichia coli (ExPEC). The examined ExPEC strains demonstrated resistance to cephalosporins, tetracyclines, and penicillins, while remaining susceptible to aminoglycosides, beta-lactamase inhibitors, carbapenems, chloramphenicols, and sulfonamides. An analysis of virulence genes identified the presence of eight genes, namely CNF-I, fyuA, fimC, papC, ompA, fimH, irp2, and iroN, which are implicated in their invasiveness and potential to inflict tissue damage. The MLST analysis revealed that all ExPEC strains were classified under either sequence type ST131 (Achtman database) or ST43 (Pasteur database). The study further determined that these strains were absent in the kennel's drinking water source, thereby ruling out water contamination as a potential factor in the emergence of ST131-type ExPEC. This study offers a theoretical framework and empirical evidence for elucidating the potential pathogenic mechanisms and clinical therapeutic strategies of ExPEC in the etiology of acute pneumonia in puppies.

Predominantly antibody deficiencies: An important underlying cause of recurrent pneumonia in adults

RATIONALE Limited information exists concerning the causes of recurrent pneumonia in adults, particularly regarding immunodeficiencies or inborn errors of immunity. OBJECTIVES This study aims to evaluate the etiology of recurrent pneumonia in the adult population, with a focus on humoral deficiency and inborn errors of immunity. METHODS A cross-sectional non-interventional study was conducted in Cali, Colombia, from January 2019 to March 2021. Consecutive patients, aged over 14 years but under 65 years, with a history of recurrent pneumonia, were included after providing consent. The study involved a thorough review of their past medical records and radiological studies. All participants underwent complete blood count and serum immunoglobulin level measurements (IgG, IgA, IgM and IgE). Further testing was carried out based on the evaluation of a clinical immunologist. RESULTS Sixty-six (66) individuals, comprising 34 females and 32 males, were enrolled in the study. The onset of symptoms occurred at an average age of 14 years (ranging from 5 to 36 years). The analysis revealed that the most prevalent cause of recurrent pneumonia was inborn errors of immunity (20 cases, 30.3%), followed by idiopathic (9 cases, 13.7%), bronchiectasis (7 cases, 10.7%), primary ciliary dyskinesia (6 cases, 9.0%), asthma (6 cases, 9.0%), and post-tuberculosis complications (5 cases, 7.6%). CONCLUSION Predominantly antibody deficiencies, along with other inborn errors of immunity, were identified as an important factor contributing to recurrent pneumonia in adults. These findings highlight the importance of these conditions as major etiological factors in the context of recurrent pneumonia in the Colombian adult population.

The Adequacy of Current Legionnaires' Disease Diagnostic Practices in Capturing the Epidemiology of Clinically Relevant Legionella: A Scoping Review.

Legionella is an underdiagnosed and underreported etiology of pneumonia. Legionella pneumophila serogroup 1 (LpSG1) is thought to be the most common pathogenic subgroup. This assumption is based on the frequent use of a urinary antigen test (UAT), only capable of diagnosing LpSG1. We aimed to explore the frequency of Legionella infections in individuals diagnosed with pneumonia and the performance of diagnostic methods for detecting Legionella infections. We conducted a scoping review to answer the following questions: (1) "Does nucleic acid testing (NAT) increase the detection of non-pneumophila serogroup 1 Legionella compared to non-NAT?"; and (2) "Does being immunocompromised increase the frequency of pneumonia caused by non-pneumophila serogroup 1 Legionella compared to non-immunocompromised individuals with Legionnaires' disease (LD)?". Articles reporting various diagnostic methods (both NAT and non-NAT) for pneumonia were extracted from several databases. Of the 3449 articles obtained, 31 were included in our review. The most common species were found to be L. pneumophila, L. longbeachae, and unidentified Legionella species appearing in 1.4%, 0.9%, and 0.6% of pneumonia cases. Nearly 50% of cases were caused by unspecified species or serogroups not detected by the standard UAT. NAT-based techniques were more likely to detect Legionella than non-NAT-based techniques. The identification and detection of Legionella and serogroups other than serogroup 1 is hampered by a lack of application of broader pan-Legionella or pan-serogroup diagnostics.

Diagnostic Value of Metagenomic next-generation sequencing and X-pert in Bronchoalveolar lavage fluid for pneumonia in HIV-infected and HIV-uninfected patients

BackgroundThe pathogens causing unexplained pneumonia in both HIV-infected or HIV-unfected patients are likely to be complex. This retrospective study aimed to characterize the etiology of pneumonia in HIV-infected and HIV-uninfected patients using bronchoalveolar lavage fluid (BALF) analysis with metagenomic next-generation sequencing (mNGS) and X-pert MTB/RIF. MethodsBetween January 2022 and May2024, 141 HIV-infected and 104 HIV-uninfected patients admitted to Nanjing Second Hospital with pneumonia were included. BALF samples were collected and analyzed using mNGS to detect bacteria, fungi, viruses, tuberculosis (TB) and non-tuberculous mycobacteria (NTM), and X-pert for TB detection. Clinical data including CD4 T-cell counts, comorbidities, and ART status were collected and analyzed. ResultsHIV-uninfected patients were found to be older and exhibited a higher prevalence of comorbidities compared to HIV-infected patients. Despite higher median CD4 T-cell counts in HIV-uninfected individuals (412 cells/μL vs. 31 cells/μL in HIV-infected), TB detection rates using X-pert and mNGS were lower than anticipated, particularly in HIV-infected patients. Mixed-pathogen infections were significantly more prevalent in HIV-infected patients, especially those with lower CD4 T-cell counts. ART use showed variable impacts on pathogen diversity, with longer treatment durations associated with reduced infection complexity but persistent immunodeficiency in some cases.In patients with pneumonia, whether HIV-infected or HIV-uninfected, pathogens often exhibit complexity, underscoring the critical role of timely mNGS and X-pert analysis of BALF for early pathogen detection.

Non-resolving pneumonia with respiratory failure: scratch your neurons too

Finding the etiology for non-resolving or recurrent pneumonia is enough to cause physicians to have sleepless nights. Moreover, if the reason turns out to be the primary presentation of neuromuscular disease, it takes all of us aback. The differential diagnosis should include atypical infections, malignancy, and neuromuscular disorder. We present a case of a 35-year-old female who presented with non-resolving pneumonia with respiratory failure but was later diagnosed with myasthenia gravis.

Purulent pericarditis and cardiac tamponade in HIV: a case report on a dreaded complication of streptococcus pneumoniae

Introduction and importance: Purulent pericarditis is an uncommon complication of Streptococcus pneumoniae, which commonly occurs in an immunocompromised state such as HIV and can lead to life-threatening complications such as cardiac tamponade and potentially death if untreated. Early identification, pericardiocentesis, and general measures such as antibiotics and anti-inflammatory medications can be life-saving. Case presentation: We present a case of a 64-year-old male with HIV who presented with clinical symptoms suggestive of pericarditis. Chest imaging revealed multifocal airspace diseases and moderate pericardial effusion. He had worsening lactic acidosis, and bedside point-of-care ultrasound showed pericardial effusion with features suggestive of cardiac tamponade. His lactic acidosis improved with emergency pericardiocentesis. Blood and pericardial fluid cultures revealed Streptococcus pneumoniae. He was further treated with intravenous antibiotics, colchicine, and ibuprofen. Clinical discussion: Although Streptococcus pneumoniae is a common etiology of community-acquired pneumonia (CAP), it has not been cited as the leading cause of pericarditis or pericardial effusion. In immunocompromised patients, it is necessary to consider a broad differential diagnosis as an etiology of acute chest pain, as it may be challenging to differentiate pleuritic and pericarditic chest pain from clinical presentation only. Moreover, infectious etiology of acute pericarditis and pericardial effusion should be considered in this patient population, especially those with HIV. At the same time, it is crucial to promptly identify and treat cardiac tamponade to prevent further deterioration. Conclusion: Our case provides insight into the diagnosis and management of CAP and its potential complication of purulent pericarditis and cardiac tamponade in immunocompromised patients.

Antibiotic De-escalation Patterns and Outcomes in Critically Ill Patients with Suspected Pneumonia as Informed by Bronchoalveolar Lavage Results.

Antibiotic stewardship in critically ill pneumonia patients is crucial yet challenging, partly due to the limited diagnostic yield of noninvasive infectious tests. In this study, we report an antibiotic prescription pattern informed by bronchoalveolar lavage (BAL) results, where clinicians de-escalate antibiotics based on the combination of quantitative cultures and multiplex PCR rapid diagnostic tests. We analyzed data from SCRIPT, a single-center prospective cohort study of mechanically ventilated patients who underwent a BAL for suspected pneumonia. We used the novel Narrow Antibiotic Therapy (NAT) score to quantify day-by-day antibiotic prescription pattern for each suspected pneumonia episode etiology (bacterial, viral, mixed bacterial/viral, microbiology-negative, and non-pneumonia control). We also analyzed and compared clinical outcomes for each pneumonia etiology, including unfavorable outcomes (a composite of in-hospital mortality, discharge to hospice, or requiring lung transplantation during hospitalization), duration of ICU stay, and duration of intubation. Clinical outcomes were compared with the Mann-Whitney U test and Fisher's exact test. We included 686 patients with 927 pneumonia episodes. NAT score analysis indicated that an antibiotic de-escalation pattern was evident in all pneumonia etiologies except resistant bacterial pneumonia. Microbiology-negative pneumonia was treated similarly to susceptible bacterial pneumonia in terms of antibiotic spectrum. Over a quarter of the time in viral pneumonia episodes, antibiotics were completely discontinued. Unfavorable outcomes were comparable across all pneumonia etiologies. Patients with viral and mixed bacterial/viral pneumonia had longer durations of ICU stay and intubation. BAL quantitative cultures and multiplex PCR rapid diagnostic tests resulted in prompt antibiotic de-escalation in critically ill pneumonia patients. There was no evidence of increased incidence of unfavorable outcomes.

Viral Etiologies of Pneumonia and Bronchiolitis in Hospitalized Children During the COVID-19 Pandemic

Background: Viral agents are the most common pathogens that can infect children between the ages of two and five. Although previous studies worldwide have investigated the viral causes of lower respiratory infections before the pandemic, researchers focused on the coronavirus with the increase in respiratory infections during the pandemic. However, it became evident that other viruses should also be monitored. Objectives: We aimed to detect viruses in cases of pneumonia and bronchiolitis in children over 2 months old during the COVID-19 emergency in Mashhad. Methods: All hospitalized children admitted to Akbar Hospital, Mashhad, Iran, from January 2021 to January 2022, with a final evidence-based diagnosis of pneumonia or bronchiolitis by an expert pediatrician were included. Convenient nasopharyngeal samples were taken and analyzed with multiplex polymerase chain reaction (PCR). Moreover, patients’ on-admission presentations were recorded. Data were reported using descriptive statistics and analyzed with IBM SPSS software. Results: We assessed 102 children with an average age of 3.80 ± 3.40 years who were admitted with pneumonia (N = 97) and bronchiolitis (N = 5). COVID-19 and respiratory syncytial virus (RSV) were the most frequent viruses in pneumonia and bronchiolitis patients, respectively. The most common symptom was cough, occurring in over 90% of the study population. Wheezing was heard in 4 out of 5 bronchiolitis cases, while crackles were more frequent in pneumonia patients (36.1%). The pulse and respiratory rates of children with bronchiolitis were significantly higher than those with pneumonia (P &lt; 0.05). Results showed that monocyte counts were significantly different between the groups, with higher counts in bronchiolitis patients. Conclusions: The study provided valuable insights into the clinical and laboratory characteristics of pneumonia and bronchiolitis in children, including viral etiology, symptoms, clinical signs, vital signs, and laboratory findings. These findings can aid healthcare professionals in diagnosing and managing these common respiratory infections in hospitalized children. Notably, more accurate follow-up is suggested, especially for viral coinfections that might cause higher rates of morbidity and mortality in children. The study provided valuable insights into the clinical and laboratory characteristics of pneumonia and bronchiolitis in children, including viral etiology, symptoms, clinical signs, vital signs, and laboratory findings. These findings can aid healthcare professionals in diagnosing and managing these common respiratory infections in hospitalized children. Notably, more accurate follow-up is suggested, especially for viral coinfections that might cause higher rates of morbidity and mortality in children.

External Validation of Two Clinical Prediction Models for Pediatric Pneumonia

ObjectiveTo externally validate two prediction models for pediatric radiographic pneumonia. MethodsWe prospectively evaluated the performance of two prediction models (Pneumonia Risk Score [PRS] and Catalyzing Ambulatory Research in Pneumonia Etiology and Diagnostic Innovations in Emergency Medicine [CARPE DIEM] models) from a prospective convenience sample of children 90 days – 18 years of age from a pediatric emergency department undergoing chest radiography for suspected pneumonia between January 1, 2022, and December 31st, 2023. We evaluated model performance using the original intercepts and coefficients and evaluated for performance changes when performing recalibration and re-estimation procedures. ResultsWe included 202 patients (median age 3 years, IQR 1–6 years), of whom radiographic pneumonia was found in 92 (41.0%). The PRS model had an area under the receiver operator characteristic curve of 0.72 (95% confidence interval [CI] 0.64–0.79), which was higher than the CARPE DIEM (0.59; 95% CI 0.51–0.67) (P < 0.01). Using optimal cutpoints, the PRS model showed higher sensitivity (65.2%, 95% CI 54.6–74.9) and specificity (72.7%, 95% CI 63.4–80.8) compared to the CARPE DIEM model (sensitivity 56.5 [95% CI 45.8–66.8]; specificity 60.9 [95% CI 50.2–69.2]). Recalibration and re-estimation of models improved performance, particularly for the CARPE DIEM model, with gains in sensitivity and specificity, and improved calibration. ConclusionThe PRS model demonstrated better performance than the CARPE DIEM model in predicting radiographic pneumonia. Among children with a high rate of pneumonia, these models did not reach a level of performance sufficient to be used independently of clinical judgment. These findings highlight the need for further validation and improvement of models to enhance their utility.

Predictive signature of murine and human host response to typical and atypical pneumonia

BackgroundPneumonia due to typical bacterial, atypical bacterial and viral pathogens can be difficult to clinically differentiate. Host response-based diagnostics are emerging as a complementary diagnostic strategy to pathogen detection.MethodsWe used...

A Systematic Review of Community-Acquired Pneumonia in Indian Adults.

This systematic review aimed to consolidate findings on the etiology of community-acquired pneumonia (CAP) among Indian adults. We adhered to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) Guidelines 2020 and conducted a comprehensive search across databases including PubMed, Scopus-Elsevier, and hand-searched reference lists using key terms such as "Community-Acquired Pneumonia," "CAP," "Indian," and "adults." Articles published between January 2010 and January 2024 were included, with exclusions for studies involving pediatric populations, non-Indian patients, or those published before 2010. From an initial pool of 344 articles, duplicates were removed and titles and abstracts were screened, resulting in nine studies meeting the inclusion criteria. The analysis of pooled data comprising 1,643 Indian adult participants revealed the following pathogen distribution: Streptococcus pneumoniae was the most common organism, accounting for 33% of the cases. This was followed by Klebsiella pneumoniae at 23%, Staphylococcus aureus at 10%, Mycoplasma pneumoniae and Legionella pneumophila each at 7%, and Chlamydia pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa each at 4%. Notably, the review highlights a rising incidence of K. pneumoniae in CAP cases, which is a significant concern and should be considered when treating CAP patients in India. The findings emphasize the importance of comprehensive diagnostic testing, including advanced methods such as bronchoalveolar lavage, urinary antigen tests, serology for atypical pathogens, and enzyme-linked immunosorbent assays, to improve diagnostic yield and guide targeted antibiotic therapy. This review underscores the need for updated empirical treatment guidelines that account for dominant pathogens. Future research should focus on employing advanced diagnostic methods to enhance understanding of CAP etiology.

The Impact of Next-Generation Sequencing Added to Multiplex PCR on Antibiotic Stewardship in Critically Ill Patients with Suspected Pneumonia.

In patients with suspected pneumonia who are tested with respiratory culture and multiplex PCR, the potential added benefit of next-generation sequencing technologies is unknown. This was a single-center, retrospective study in which residual bronchoalveolar lavage (BAL) specimens were retrieved from hospitalized patients. We compared its research-use-only Respiratory Pathogen Illumina Panel (RPIP) results to culture and BioFire® FilmArray Pneumonia Panel (BioFire® PN) results from critically ill patients. In total, 47 BAL specimens from 47 unique patients were included. All BAL samples were tested with culture and multiplex PCR. In total, 38 of the 47 BALs were consistent with a clinical picture of pneumonia per chart review. Additional testing of the 38 samples with the RPIP identified a new bacterium in 20 patients, a new virus in 4 patients, a new bacterium plus virus in 4 patients, and no additional organisms in 10 patients. In 17 (44.5%) of these patients, the RPIP results could have indicated an antibiotic addition. Compared with cultures, the RPIP had an overall sensitivity of 64% and specificity of 98%, with a 0% sensitivity for fungus and 14% sensitivity for mycobacteria. Compared with BioFire® PN, the RPIP was 70% sensitive and 99% specific, with a 74% sensitivity for bacteria and 33% sensitivity for viruses. The RPIP was 29% more sensitive for HAP/VAP bacterial targets compared with CAP. Emerging NGS technologies such as the RPIP may have a role in identifying the etiology of pneumonia, even when patients have BAL culture and multiplex PCR results available. Similar to prior studies evaluating RPIP, our study showed this platform lacked sensitivity when compared with cultures, particularly for fungi and mycobacteria. However, the high specificity of the test can be leveraged when clinicians are seeking to rule out certain infections.