BinaxNOW <i>Streptococcus pneumoniae</i> Antigen Assay in Pleural Fluid for Detection of <i>S pneumoniae</i> in Children With Empyema

Recent studies using polymerase chain reaction (PCR) demonstrate that blood and pleural fluid (PF) cultures are inadequate to identify pneumococcus in children with pneumonia and empyema, leading to unnecessary utilization of broad-spectrum, often toxic antibiotics. Identification of pneumococcus facilitates the de-escalation of antibiotics. We compared a point-of-care immunochromatographic test that detects pneumococcal C-polysaccharide antigen (BINAX) performed in PF and urine to cultures (blood and PF) and 2 different PCR tests in PF of 79 children with empyema. BINAX in PF had 100% sensitivity and negative predictive value (NPV) to identify pneumococcus in children with empyema, compared with cultures (sensitivity 20.7%/NPV = 68.8%) or PCR (sensitivity 96.5%/NPV 98%). Urine BINAX demonstrated lower sensitivity (89%) and NPV (93%). BINAX in PF is superior to cultures (PF and blood), identifying pneumococcus in children with empyema. PCR has similar sensitivity and NPV to BINAX but is not readily available.