Association of Radiology Findings with Etiology of Community Acquired Pneumonia among Children.

OBJECTIVE: To evaluate the association between consolidation on chest radiograph and typical bacterial etiology of childhood community acquired pneumonia (CAP) in the Etiology of Pneumonia in the Community study. STUDY DESIGN: Hospitalized children <18 years of age with CAP enrolled in the Etiology of Pneumonia in the Community study at 3 children's hospitals between January 2010 and June 2012 were included. Testing of blood and respiratory specimens used multiple modalities to identify typical and atypical bacterial, or viral infection. Study radiologists classified chest radiographs (consolidation, other infiltrates [interstitial and/or alveolar], pleural effusion) using modified World Health Organization pneumonia criteria. Infiltrate patterns were compared according to etiology of CAP. RESULTS: Among 2212 children, there were 1302 (59%) with consolidation with or without other infiltrates, 910 (41%) with other infiltrates, and 296 (13%) with pleural effusion. In 1795 children, at least 1 pathogen was detected. Among these patients, consolidation (74%) was the most frequently observed pattern (74% in typical bacterial CAP, 58% in atypical bacterial CAP, and 54% in viral CAP). Positive and negative predictive values of consolidation for typical bacterial CAP were 12% (95% CI 10%-15%) and 96% (95% CI 95%-97%) respectively. In a multivariable model, typical bacterial CAP was associated with pleural effusion (OR 7.3, 95% CI 4.7-11.2) and white blood cell ≥15 000/mL (OR 3.2, 95% CI 2.2-4.9), and absence of wheeze (OR 0.5, 95% CI 0.3-0.8) or viral detection (OR 0.2, 95% CI 0.1-0.4). CONCLUSIONS: Consolidation predicted typical bacterial CAP poorly, but its absence made typical bacterial CAP unlikely. Pleural effusion was the best predictor of typical bacterial infection, but too uncommon to aid etiology prediction.

Prevalence, Risk Factors, and Outcomes of Bacteremic Pneumonia in Children.

BACKGROUND: Previous studies examining bacteremia in hospitalized children with pneumonia are limited by incomplete culture data. We sought to determine characteristics of children with bacteremic pneumonia using data from a large prospective study with systematic blood culturing. METHODS: Children <18 years hospitalized with pneumonia and enrolled in the multicenter Etiology of Pneumonia in the Community study between January 2010 and June 2012 were eligible. Bivariate comparisons were used to identify factors associated with bacteremia. Associations between bacteremia and clinical outcomes were assessed by using Cox proportional hazards regression for length of stay and logistic regression for ICU admission and invasive mechanical ventilation or shock. RESULTS: Blood cultures were obtained in 2143 (91%) of 2358 children; 46 (2.2%) had bacteremia. The most common pathogens were Streptococcus pneumoniae (n = 23, 50%), Staphylococcus aureus (n = 6, 13%), and Streptococcus pyogenes (n = 4, 9%). Characteristics associated with bacteremia included male sex, parapneumonic effusion, lack of chest indrawing or wheezing, and no previous receipt of antibiotics. Children with bacteremia had longer lengths of stay (median: 5.8 vs 2.8 days; adjusted hazard ratio: 0.79 [0.73-0.86]) and increased odds of ICU admission (43% vs 21%; adjusted odds ratio: 5.21 [3.82-6.84]) and invasive mechanical ventilation or shock (30% vs 8%; adjusted odds ratio: 5.28 [2.41-11.57]). CONCLUSIONS: Bacteremia was uncommonly detected in this large multicenter cohort of children hospitalized with community-acquired pneumonia but was associated with severe disease. S pneumoniae was detected most often. Blood culture was of low yield in general but may have greater use in those with parapneumonic effusion and ICU admission.

Mycoplasma pneumoniae Among Children Hospitalized With Community-acquired Pneumonia.

Background: The epidemiology of Mycoplasma pneumoniae (Mp) among US children (<18 years) hospitalized with community-acquired pneumonia (CAP) is poorly understood. Methods: In the Etiology of Pneumonia in the Community study, we prospectively enrolled 2254 children hospitalized with radiographically confirmed pneumonia from January 2010-June 2012 and tested nasopharyngeal/oropharyngeal swabs for Mp using real-time polymerase chain reaction (PCR). Clinical and epidemiological features of Mp PCR-positive and -negative children were compared using logistic regression. Macrolide susceptibility was assessed by genotyping isolates. Results: One hundred and eighty two (8%) children were Mp PCR-positive (median age, 7 years); 12% required intensive care and 26% had pleural effusion. No in-hospital deaths occurred. Macrolide resistance was found in 4% (6/169) isolates. Of 178 (98%) Mp PCR-positive children tested for copathogens, 50 (28%) had ≥1 copathogen detected. Variables significantly associated with higher odds of Mp detection included age (10-17 years: adjusted odds ratio [aOR], 10.7 [95% confidence interval {CI}, 5.4-21.1] and 5-9 years: aOR, 6.4 [95% CI, 3.4-12.1] vs 2-4 years), outpatient antibiotics ≤5 days preadmission (aOR, 2.3 [95% CI, 1.5-3.5]), and copathogen detection (aOR, 2.1 [95% CI, 1.3-3.3]). Clinical characteristics were non-specific. Conclusions: Usually considered as a mild respiratory infection, Mp was the most commonly detected bacteria among children aged ≥5 years hospitalized with CAP, one-quarter of whom had codetections. Although associated with clinically nonspecific symptoms, there was a need for intensive care in some cases. Mycoplasma pneumoniae should be included in the differential diagnosis for school-aged children hospitalized with CAP.

Pneumococcal and Legionella Urinary Antigen Tests in Community-acquired Pneumonia: Prospective Evaluation of Indications for Testing.

BACKGROUND: Adult, community-acquired pneumonia (CAP) guidelines from the Infectious Diseases Society of America (IDSA) and American Thoracic Society (ATS) include indications for urinary antigen tests (UATs) for Streptococcus pneumoniae (SP) and Legionella pneumophila (LP). These recommendations were based on expert opinions and have not been rigorously evaluated. METHODS: We used data from a multicenter, prospective, surveillance study of adults hospitalized with CAP to evaluate the sensitivity and specificity of the IDSA/ATS UAT indications for identifying patients who test positive. SP and LP UATs were completed on all included patients. Separate analyses were completed for SP and LP, using 2-by-2 contingency tables, comparing the IDSA/ATS indications (UAT recommended vs not recommended) and UAT results (positive vs negative). Additionally, logistic regression was used to evaluate the association of each individual criterion in the IDSA/ATS indications with positive UAT results. RESULTS: Among 1941 patients, UATs were positive for SP in 81 (4.2%) and for LP in 32 (1.6%). IDSA/ATS indications had 61% sensitivity (95% confidence interval [CI] 49-71%) and 39% specificity (95% CI 37-41%) for SP, and 63% sensitivity (95% CI 44-79%) and 35% specificity (95% CI 33-37%) for LP. No clinical characteristics were strongly associated with positive SP UATs, while features associated with positive LP UATs were hyponatremia, fever, diarrhea, and recent travel. CONCLUSIONS: Recommended indications for SP and LP urinary antigen testing in the IDSA/ATS CAP guidelines have poor sensitivity and specificity for identifying patients with positive tests; future CAP guidelines should consider other strategies for determining which patients should undergo urinary antigen testing.

Serological response to influenza vaccination among adults hospitalized with community-acquired pneumonia.

Ninety-five adults enrolled in the Etiology of Pneumonia in the Community study with negative admission influenza polymerase chain reaction (PCR) tests received influenza vaccination during hospitalization. Acute and convalescent influenza serology was performed. After vaccination, seropositive (≥1:40) hemagglutination antibody titers (HAI) were achieved in 55% to influenza A(H1N1)pdm09, 58% to influenza A(H3N2), 77% to influenza B (Victoria), and 74% to influenza B (Yamagata) viruses. Sixty-six (69%) patients seroconverted (≥4-fold HAI rise) to ≥1 strain. Failure to seroconvert was associated with diabetes, bacterial detection, baseline seropositive titers for influenza B (Yamagata), and influenza vaccination in the previous season.

Low Admission Plasma Gelsolin Concentrations Identify Community-acquired Pneumonia Patients at High Risk for Severe Outcomes.

BACKGROUND: Plasma gelsolin (pGSN) is an abundant circulating protein that neutralizes actin exposed by damaged cells, modulates inflammatory responses, and enhances alveolar macrophage antimicrobial activity. We investigated whether adults with low pGSN at hospital admission for community-acquired pneumonia (CAP) were at high risk for severe outcomes. METHODS: Admission pGSN concentrations in 455 adults hospitalized with CAP were measured using enzyme-linked immunosorbent assay. Patients were grouped into the following 4 hierarchical, mutually exclusive categories based on maximum clinical severity experienced during their hospitalization: general floor care without intensive care unit (ICU) admission, invasive respiratory or vasopressor support (IRVS), or death; ICU care without IRVS or death; IRVS without death; or death. Admission pGSN concentrations were compared across these discrete outcome categories. Additionally, outcomes among patients in the lowest quartile of pGSN concentration were compared to those in the upper 3 quartiles. RESULTS: Overall, median (interquartile range) pGSN concentration was 38.1 (32.1, 45.7) µg/mL. Patients with more severe outcomes had lower pGSN concentrations (P = .0001); median values were 40.3 µg/mL for floor patients, 36.7 µg/mL for ICU patients, 36.5 µg/mL for patients receiving IRVS, and 25.7 µg/mL for patients who died. Compared to patients with higher pGSN concentrations, patients in the lowest quartile (pGSN ≤ 32.1 µg/mL) more often required IRVS (21.2% vs 11.7%, P = .0114) and died (8.8% vs 0.9%, P < .0001). CONCLUSIONS: Among adults hospitalized with CAP, lower pGSN concentrations were associated with more severe clinical outcomes. Future studies are planned to investigate possible therapeutic benefits of recombinant human pGSN in this population.

Use of Multiple Imputation to Estimate the Proportion of Respiratory Virus Detections Among Patients Hospitalized With Community-Acquired Pneumonia.

BACKGROUND: Real-time polymerase chain reaction (PCR) on respiratory specimens and serology on paired blood specimens are used to determine the etiology of respiratory illnesses for research studies. However, convalescent serology is often not collected. We used multiple imputation to assign values for missing serology results to estimate virus-specific prevalence among pediatric and adult community-acquired pneumonia hospitalizations using data from an active population-based surveillance study. METHODS: Presence of adenoviruses, human metapneumovirus, influenza viruses, parainfluenza virus types 1-3, and respiratory syncytial virus was defined by positive PCR on nasopharyngeal/oropharyngeal specimens or a 4-fold rise in paired serology. We performed multiple imputation by developing a multivariable regression model for each virus using data from patients with available serology results. We calculated absolute and relative differences in the proportion of each virus detected comparing the imputed to observed (nonimputed) results. RESULTS: Among 2222 children and 2259 adults, 98.8% and 99.5% had nasopharyngeal/oropharyngeal specimens and 43.2% and 37.5% had paired serum specimens, respectively. Imputed results increased viral etiology assignments by an absolute difference of 1.6%-4.4% and 0.8%-2.8% in children and adults, respectively; relative differences were 1.1-3.0 times higher. CONCLUSIONS: Multiple imputation can be used when serology results are missing, to refine virus-specific prevalence estimates, and these will likely increase estimates.

In-Hospital Deaths Among Adults With Community-Acquired Pneumonia.

BACKGROUND: Adults hospitalized with community-acquired pneumonia (CAP) are at high risk for short-term mortality. However, it is unclear whether improvements in in-hospital pneumonia care could substantially lower this risk. We extensively reviewed all in-hospital deaths in a large prospective CAP study to assess the cause of each death and assess the extent of potentially preventable mortality. METHODS: We enrolled adults hospitalized with CAP at five tertiary-care hospitals in the United States. Five physician investigators reviewed the medical record and study database for each patient who died to identify the cause of death, the contribution of CAP to death, and any preventable factors potentially contributing to death. RESULTS: Among 2,320 enrolled patients, 52 (2.2%) died during initial hospitalization. Among these 52 patients, 33 (63.4%) were ≥ 65 years old, and 32 (61.5%) had ≥ two chronic comorbidities. CAP was judged to be the direct cause of death in 27 patients (51.9%). Ten patients (19.2%) had do-not-resuscitate orders prior to admission. Four patients were identified in whom a lapse in quality of care potentially contributed to death; preexisting end-of-life limitations were present in two of these patients. Two patients seeking full medical care experienced a lapse in in-hospital quality of pneumonia care that potentially contributed to death. CONCLUSIONS: In this study of adults with CAP at tertiary-care hospitals with a low mortality rate, most in-hospital deaths did not appear to be preventable with improvements in in-hospital pneumonia care. Preexisting end-of-life limitations in care, advanced age, and high comorbidity burden were common among those who died.

Community-Acquired Pneumonia Visualized on CT Scans but Not Chest Radiographs: Pathogens, Severity, and Clinical Outcomes.

BACKGROUND: The clinical significance of pneumonia visualized on CT scan in the setting of a normal chest radiograph is uncertain. METHODS: In a multicenter prospective surveillance study of adults hospitalized with community-acquired pneumonia (CAP), we compared the presenting clinical features, pathogens present, and outcomes of patients with pneumonia visualized on a CT scan but not on a concurrent chest radiograph (CT-only pneumonia) and those with pneumonia visualized on a chest radiograph. All patients underwent chest radiography; the decision to obtain CT imaging was determined by the treating clinicians. Chest radiographs and CT images were interpreted by study-dedicated thoracic radiologists blinded to the clinical data. RESULTS: The study population included 2,251 adults with CAP; 2,185 patients (97%) had pneumonia visualized on chest radiography, whereas 66 patients (3%) had pneumonia visualized on CT scan but not on concurrent chest radiography. Overall, these patients with CT-only pneumonia had a clinical profile similar to those with pneumonia visualized on chest radiography, including comorbidities, vital signs, hospital length of stay, prevalence of viral (30% vs 26%) and bacterial (12% vs 14%) pathogens, ICU admission (23% vs 21%), use of mechanical ventilation (6% vs 5%), septic shock (5% vs 4%), and inhospital mortality (0 vs 2%). CONCLUSIONS: Adults hospitalized with CAP who had radiological evidence of pneumonia on CT scan but not on concurrent chest radiograph had pathogens, disease severity, and outcomes similar to patients who had signs of pneumonia on chest radiography. These findings support using the same management principles for patients with CT-only pneumonia and those with pneumonia seen on chest radiography.

Etiology and Impact of Coinfections in Children Hospitalized With Community-Acquired Pneumonia.

Background: Recognition that coinfections are common in children with community-acquired pneumonia (CAP) is increasing, but gaps remain in our understanding of their frequency and importance. Methods: We analyzed data from 2219 children hospitalized with CAP and compared demographic and clinical characteristics and outcomes between groups with viruses alone, bacteria alone, or coinfections. We also assessed the frequency of selected pairings of codetected pathogens and their clinical characteristics. Results: A total of 576 children (26%) had a coinfection. Children with only virus detected were younger, more likely to be black, and more likely to have comorbidities such as asthma, compared with children infected with typical bacteria alone. Children with virus-bacterium coinfections had a higher frequency of leukocytosis, consolidation on chest radiography, parapneumonic effusions, intensive care unit admission, and need for mechanical ventilation and an increased length of stay, compared with children infected with viruses alone. Virus-virus coinfections were generally comparable to single-virus infections, with the exception of the need for oxygen supplementation, which was higher during the first 24 hours of hospitalization in some virus-virus pairings. Conclusions: Coinfections occurred in 26% of children hospitalized for CAP. Children with typical bacterial infections, alone or complicated by a viral infection, have worse outcomes than children infected with a virus alone.

Rhinovirus Viremia in Patients Hospitalized With Community-Acquired Pneumonia.

Background: Rhinoviruses (RVs) are ubiquitous respiratory pathogens that often cause mild or subclinical infections. Molecular detection of RVs from the upper respiratory tract can be prolonged, complicating etiologic association in persons with severe lower respiratory tract infections. Little is known about RV viremia and its value as a diagnostic indicator in persons hospitalized with community-acquired pneumonia (CAP). Methods: Sera from RV-positive children and adults hospitalized with CAP were tested for RV by real-time reverse-transcription polymerase chain reaction. Rhinovirus species and type were determined by partial genome sequencing. Results: Overall, 57 of 570 (10%) RV-positive patients were viremic, and all were children aged <10 years (n = 57/375; 15.2%). Although RV-A was the most common RV species detected from respiratory specimens (48.8%), almost all viremias were RV-C (98.2%). Viremic patients had fewer codetected pathogens and were more likely to have chest retractions, wheezing, and a history of underlying asthma/reactive airway disease than patients without viremia. Conclusions: More than 1 out of 7 RV-infected children aged <10 years hospitalized with CAP were viremic. In contrast with other RV species, RV-C infections were highly associated with viremia and were usually the only respiratory pathogen identified, suggesting that RV-C viremia may be an important diagnostic indicator in pediatric pneumonia.

Effectiveness of ß-Lactam Monotherapy vs Macrolide Combination Therapy for Children Hospitalized With Pneumonia.

Importance: ß-Lactam monotherapy and ß-lactam plus macrolide combination therapy are both common empirical treatment strategies for children hospitalized with pneumonia, but few studies have evaluated the effectiveness of these 2 treatment approaches. Objective: To compare the effectiveness of ß-lactam monotherapy vs ß-lactam plus macrolide combination therapy among a cohort of children hospitalized with pneumonia. Design, Setting, and Participants: We analyzed data from the Etiology of Pneumonia in the Community Study, a multicenter, prospective, population-based study of community-acquired pneumonia hospitalizations conducted from January 1, 2010, to June 30, 2012, in 3 children's hospitals in Nashville, Tennessee; Memphis, Tennessee; and Salt Lake City, Utah. The study included all children (up to 18 years of age) who were hospitalized with radiographically confirmed pneumonia and who received ß-lactam monotherapy or ß-lactam plus macrolide combination therapy. Data analysis was completed in April 2017. Main Outcomes and Measures: We defined the referent as ß-lactam monotherapy, including exclusive use of an oral or parenteral second- or third-generation cephalosporin, penicillin, ampicillin, ampicillin-sulbactam, amoxicillin, or amoxicillin-clavulanate. Use of a ß-lactam plus an oral or parenteral macrolide (azithromycin or clarithromycin) served as the comparison group. We modeled the association between these groups and patients' length of stay using multivariable Cox proportional hazards regression. Covariates included demographic, clinical, and radiographic variables. We further evaluated length of stay in a cohort matched by propensity to receive combination therapy. Logistic regression was used to evaluate secondary outcomes in the unmatched cohort, including intensive care admission, rehospitalizations, and self-reported recovery at follow-up. Results: Our study included 1418 children (693 girls and 725 boys) with a median age of 27 months (interquartile range, 12-69 months). This cohort was 60.1% of the 2358 children enrolled in the Etiology of Pneumonia in the Community Study with radiographically confirmed pneumonia in the study period; 1019 (71.9%) received ß-lactam monotherapy and 399 (28.1%) received ß-lactam plus macrolide combination therapy. In the unmatched cohort, there was no statistically significant difference in length of hospital stay between children receiving ß-lactam monotherapy and combination therapy (median, 55 vs 59 hours; adjusted hazard ratio, 0.87; 95% CI, 0.74-1.01). The propensity-matched cohort (n = 560, 39.5%) showed similar results. There were also no significant differences between treatment groups for the secondary outcomes. Conclusions and Relevance: Empirical macrolide combination therapy conferred no benefit over ß-lactam monotherapy for children hospitalized with community-acquired pneumonia. The results of this study elicit questions about the routine empirical use of macrolide combination therapy in this population.

Antibiotic Prescribing for Adults Hospitalized in the Etiology of Pneumonia in the Community Study.

BACKGROUND: Community-acquired pneumonia (CAP) 2007 guidelines from the Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) recommend a respiratory fluoroquinolone or beta-lactam plus macrolide as first-line antibiotics for adults hospitalized with CAP. Few studies have assessed guideline-concordant antibiotic use for patients hospitalized with CAP after the 2007 IDSA/ATS guidelines. We examine antibiotics prescribed and associated factors in adults hospitalized with CAP. METHODS: From January 2010 to June 2012, adults hospitalized with clinical and radiographic CAP were enrolled in a prospective Etiology of Pneumonia in the Community study across 5 US hospitals. Patients were interviewed using a standardized questionnaire, and medical charts were reviewed. Antibiotics prescribed were classified according to defined nonrecommended CAP antibiotics. We assessed factors associated with nonrecommended CAP antibiotics using logistic regression. RESULTS: Among enrollees, 1843 of 1874 (98%) ward and 440 of 446 (99%) ICU patients received ≥1 antibiotic ≤24 hours after admission. Ward patients were prescribed a respiratory fluoroquinolone alone (n = 613; 33%), or beta-lactam plus macrolide (n = 365; 19%), beta-lactam alone (n = 240; 13%), among other antibiotics, including vancomycin (n = 235; 13%) or piperacillin/tazobactam (n = 157; 8%) ≤24 hours after admission. Ward patients with known risk for healthcare-associated pneumonia (HCAP), recent outpatient antibiotic use, and in-hospital antibiotic use <6 hours after admission were significantly more likely to receive nonrecommended CAP antibiotics. CONCLUSIONS: Although more than half of ward patients received antibiotics concordant with IDSA/ATS guidelines, a number received nonrecommended CAP antibiotics, including vancomycin and piperacillin/tazobactam; risk factors for HCAP, recent outpatient antibiotic, and rapid inpatient antibiotic use contributed to this. This hypothesis-generating descriptive epidemiology analysis could help inform antibiotic stewardship efforts, reinforces the need to harmonize guidelines for CAP and HCAP, and highlights the need for improved diagnostics to better equip clinicians.

Low Retinol-Binding Protein and Vitamin D Levels Are Associated with Severe Outcomes in Children Hospitalized with Lower Respiratory Tract Infection and Respiratory Syncytial Virus or Human Metapneumovirus Detection.

Retinol binding protein and vitamin D were measured in children aged <5 years hospitalized with lower respiratory tract infection and respiratory syncytial virus and/or human metapneumovirus detections. Low vitamin levels were observed in 50% of the children and were associated with significantly elevated risk of the need for intensive care unit admission and invasive mechanical ventilation.

Influence of Antibiotics on the Detection of Bacteria by Culture-Based and Culture-Independent Diagnostic Tests in Patients Hospitalized With Community-Acquired Pneumonia.

BACKGROUND: Specimens collected after antibiotic exposure may reduce culture-based bacterial detections. The impact on culture-independent diagnostic tests is unclear. We assessed the effect of antibiotic exposure on both of these test results among patients hospitalized with community-acquired pneumonia (CAP). METHODS: Culture-based bacterial testing included blood cultures and high-quality sputum or endotracheal tube (ET) aspirates; culture-independent testing included urinary antigen testing (adults) for Streptococcus pneumoniae and Legionella pneumophila and polymerase chain reaction (PCR) on nasopharyngeal and oropharyngeal (NP/OP) swabs for Mycoplasma pneumoniae and Chlamydia pneumoniae. The proportion of bacterial detections was compared between specimens collected before and after either any antibiotic exposure (prehospital and/or inpatient) or only prehospital antibiotics and increasing time after initiation of inpatient antibiotics. RESULTS: Of 4678 CAP patients, 4383 (94%) received antibiotics: 3712 (85%) only inpatient, 642 (15%) both inpatient and prehospital, and 29 (<1%) only prehospital. There were more bacterial detections in specimens collected before antibiotics for blood cultures (5.2% vs 2.6%; P < .01) and sputum/ET cultures (50.0% vs 26.8%; P < .01) but not urine antigen (7.0% vs 5.7%; P = .53) or NP/OP PCR (6.7% vs 5.4%; P = .31). For all diagnostic testing, bacterial detections declined with increasing time between inpatient antibiotic administration and specimen collection. CONCLUSIONS: Bacteria were less frequently detected in culture-based tests collected after antibiotics and in culture-independent tests that had longer intervals between antibiotic exposure and specimen collection. Bacterial yield could improve if specimens were collected promptly, preferably before antibiotics, providing data for improved antibiotic selection.

Relationship Between Body Mass Index and Outcomes Among Hospitalized Patients With Community-Acquired Pneumonia.

Background: The effect of body mass index (BMI) on community-acquired pneumonia (CAP) severity is unclear. Methods: We investigated the relationship between BMI and CAP outcomes (hospital length of stay [LOS], intensive care unit [ICU] admission, and invasive mechanical ventilation) in hospitalized CAP patients from the Centers for Disease Control and Prevention Etiology of Pneumonia in the Community (EPIC) study, adjusting for age, demographics, underlying conditions, and smoking status (adults only). Results: Compared with normal-weight children, odds of ICU admission were higher in children who were overweight (adjusted odds ratio [aOR], 1.7; 95% confidence interval [CI], 1.1-2.8) or obese (aOR, 2.1; 95% CI, 1.4-3.2), and odds of mechanical ventilation were higher in children with obesity (aOR, 2.7; 95% CI, 1.3-5.6). When stratified by asthma (presence/absence), these findings remained significant only in children with asthma. Compared with normal-weight adults, odds of LOS >3 days were higher in adults who were underweight (aOR, 1.6; 95% CI, 1.1-2.4), and odds of mechanical ventilation were lowest in adults who were overweight (aOR, 0.5; 95% CI, .3-.9). Conclusions: Children who were overweight or obese, particularly those with asthma, had higher odds of ICU admission or mechanical ventilation. In contrast, adults who were underweight had longer LOS. These results underscore the complex relationship between BMI and CAP outcomes.

Procalcitonin as a Marker of Etiology in Adults Hospitalized With Community-Acquired Pneumonia.

BACKGROUND: Recent trials suggest procalcitonin-based guidelines can reduce antibiotic use for respiratory infections. However, the accuracy of procalcitonin to discriminate between viral and bacterial pneumonia requires further dissection. METHODS: We evaluated the association between serum procalcitonin concentration at hospital admission with pathogens detected in a multicenter prospective surveillance study of adults hospitalized with community-acquired pneumonia. Systematic pathogen testing included cultures, serology, urine antigen tests, and molecular detection. Accuracy of procalcitonin to discriminate between viral and bacterial pathogens was calculated. RESULTS: Among 1735 patients, pathogens were identified in 645 (37%), including 169 (10%) with typical bacteria, 67 (4%) with atypical bacteria, and 409 (24%) with viruses only. Median procalcitonin concentration was lower with viral pathogens (0.09 ng/mL; interquartile range [IQR], <0.05-0.54 ng/mL) than atypical bacteria (0.20 ng/mL; IQR, <0.05-0.87 ng/mL; P = .05), and typical bacteria (2.5 ng/mL; IQR, 0.29-12.2 ng/mL; P < .01). Procalcitonin discriminated bacterial pathogens, including typical and atypical bacteria, from viral pathogens with an area under the receiver operating characteristic (ROC) curve of 0.73 (95% confidence interval [CI], .69-.77). A procalcitonin threshold of 0.1 ng/mL resulted in 80.9% (95% CI, 75.3%-85.7%) sensitivity and 51.6% (95% CI, 46.6%-56.5%) specificity for identification of any bacterial pathogen. Procalcitonin discriminated between typical bacteria and the combined group of viruses and atypical bacteria with an area under the ROC curve of 0.79 (95% CI, .75-.82). CONCLUSIONS: No procalcitonin threshold perfectly discriminated between viral and bacterial pathogens, but higher procalcitonin strongly correlated with increased probability of bacterial pathogens, particularly typical bacteria.

Improved Detection of Respiratory Pathogens by Use of High-Quality Sputum with TaqMan Array Card Technology.

New diagnostic platforms often use nasopharyngeal or oropharyngeal (NP/OP) swabs for pathogen detection for patients hospitalized with community-acquired pneumonia (CAP). We applied multipathogen testing to high-quality sputum specimens to determine if more pathogens can be identified relative to NP/OP swabs. Children (<18 years old) and adults hospitalized with CAP were enrolled over 2.5 years through the Etiology of Pneumonia in the Community (EPIC) study. NP/OP specimens with matching high-quality sputum (defined as ≤10 epithelial cells/low-power field [lpf] and ≥25 white blood cells/lpf or a quality score [q-score] definition of 2+) were tested by TaqMan array card (TAC), a multipathogen real-time PCR detection platform. Among 236 patients with matched specimens, a higher proportion of sputum specimens had ≥1 pathogen detected compared with NP/OP specimens in children (93% versus 68%; P < 0.0001) and adults (88% versus 61%; P < 0.0001); for each pathogen targeted, crossing threshold (CT) values were earlier in sputum. Both bacterial (361 versus 294) and viral detections (245 versus 140) were more common in sputum versus NP/OP specimens, respectively, in both children and adults. When available, high-quality sputum may be useful for testing in hospitalized CAP patients.

Predicting Severe Pneumonia Outcomes in Children.

BACKGROUND: Substantial morbidity and excessive care variation are seen with pediatric pneumonia. Accurate risk-stratification tools to guide clinical decision-making are needed. METHODS: We developed risk models to predict severe pneumonia outcomes in children (<18 years) by using data from the Etiology of Pneumonia in the Community Study, a prospective study of community-acquired pneumonia hospitalizations conducted in 3 US cities from January 2010 to June 2012. In-hospital outcomes were organized into an ordinal severity scale encompassing severe (mechanical ventilation, shock, or death), moderate (intensive care admission only), and mild (non-intensive care hospitalization) outcomes. Twenty predictors, including patient, laboratory, and radiographic characteristics at presentation, were evaluated in 3 models: a full model included all 20 predictors, a reduced model included 10 predictors based on expert consensus, and an electronic health record (EHR) model included 9 predictors typically available as structured data within comprehensive EHRs. Ordinal regression was used for model development. Predictive accuracy was estimated by using discrimination (concordance index). RESULTS: Among the 2319 included children, 21% had a moderate or severe outcome (14% moderate, 7% severe). Each of the models accurately identified risk for moderate or severe pneumonia (concordance index across models 0.78-0.81). Age, vital signs, chest indrawing, and radiologic infiltrate pattern were the strongest predictors of severity. The reduced and EHR models retained most of the strongest predictors and performed as well as the full model. CONCLUSIONS: We created 3 risk models that accurately estimate risk for severe pneumonia in children. Their use holds the potential to improve care and outcomes.

Association of sputum microbiota profiles with severity of community-acquired pneumonia in children.

BACKGROUND: Competitive interactions among bacteria in the respiratory tract microbiota influence which species can colonize and potentially contribute to pathogenesis of community-acquired pneumonia (CAP). However, understanding of the role of respiratory tract microbiota in the clinical course of pediatric CAP is limited. METHODS: We sought to compare microbiota profiles in induced sputum and nasopharyngeal/oropharyngeal (NP/OP) samples from children and to identify microbiota profiles associated with CAP severity. We used 16S ribosomal RNA sequencing and several measures of microbiota profiles, including principal component analysis (PCA), to describe the respiratory microbiota in 383 children, 6 months to <18 years, hospitalized with CAP. We examined associations between induced sputum and NP/OP microbiota profiles and CAP severity (hospital length of stay and intensive care unit admission) using logistic regression. RESULTS: Relative abundance of bacterial taxa differed in induced sputum and NP/OP samples. In children 6 months to < 5 years, the sputum PCA factor with high relative abundance of Actinomyces, Veillonella, Rothia, and Lactobacillales was associated with decreased odds of length of stay ≥ 4 days [adjusted odds ratio (aOR) 0.69; 95 % confidence interval (CI) 0.48-0.99]. The sputum factor with high relative abundance of Haemophilus and Pasteurellaceae was associated with increased odds of intensive care unit admission [aOR 1.52; 95 % CI 1.02-2.26]. In children 5 to < 18 years, the sputum factor with high relative abundance of Porphyromonadaceae, Bacteriodales, Lactobacillales, and Prevotella was associated with increased odds of length of stay ≥ 4 days [aOR 1.52; 95 % CI 1.02-2.26]. Taxa in NP/OP samples were not associated with CAP severity. CONCLUSION: Certain taxa in the respiratory microbiota, which were detected in induced sputum samples, are associated with the clinical course of CAP.