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.