Pleural antigen assay in the diagnosis of pediatric pneumococcal empyema

Abstract

Purpose: The purpose of the study was to assess the diagnostic value of rapid pneumococcal antigen detection (PAD) in pleural fluid samples of children with empyema.

Material and methods: We performed a prospective evaluation in a pediatric intensive care unit of a tertiary university hospital of children aged 1 month to 14 years admitted with empyema. Standard cultures (conventional microbiological culture [CMC]), PAD by immunochromatographic testing (Binax NOW Streptococcus pneumoniae; Binax, Portland, ME), and/or real-time polymerase chain reactions (RTPs) on pleural samples were performed in all included patients.

Results: Fifty-five cases with a mean (SD) age of 6.5 (6.1) years were enrolled. Streptococcus pneumoniae was identified in 28 cases (51%): by CMC in 15 cases and by RTP in a further 13 cases. Using CMC and/or RTP as the criterion standard, PAD showed a sensitivity of 96% (95% confidence interval, 86%-100%), a specificity of 100% (75%-100%), a positive predictive value of 100% (98%-100%), and a Youden index of 0.96 (0.88-1.04).

Conclusions: Pneumococcal antigen detection in pleural fluid specimens from children provides a rapid, simple, sensitive, and reliable method of diagnosis for pneumococcal empyema at bedside.