Characteristics of Streptococcus pyogenes Versus Streptococcus pneumoniae Pleural Empyema and Pneumonia With Pleural Effusion in Children.

Background: Streptococcus pneumoniae is the most common cause of complicated pneumonia in children, but its incidence is decreasing since the introduction of the antipneumococcal conjugated vaccines. Streptococcus pyogenes is an uncommon cause of community-acquired pleuropneumonia/empyema in children, but its relative incidence is rising.

Methods: The medical records of all children 0-18 years of age from 2004 to 2019, with discharge diagnoses of pleuropneumonia or empyema, and a positive blood and/or pleural effusion culture for group A streptococcus (GAS) (S. pyogenes), or S. pneumonia (SP) were reviewed. A comparison of clinical and laboratory characteristics for the 2 etiologies was performed.

Results: Ninety cases of community-acquired pleuropneumonia/empyema caused by these organisms were included: 20 GAS and 70 SP. Compared with children with SP, those with GAS were more likely to have larger pleural effusion requiring drainage and longer hospitalization, and less likely to have a positive blood culture. The relative portion of GAS empyema increased over the study period.

Conclusions: Compared with patients with SP empyema, GAS appears to cause more morbidity and a longer hospital stay. This organism is more frequently recovered from pleural fluid without bacteremia, and thus necessitates pleural fluid tap for accurate diagnosis.