Parapneumonic empyema in children before the era of pneumococcal vaccination

Background: During the past two decades, the incidence of paediatric empyema has increased in many countries. Purpose: The aim of this retrospective hospital chart review was to evaluate the incidence, aetiology and clinical and laboratory characteristics of parapneumonic empyema in children. Subjects and methods: Twenty‐one patients were admitted to a university hospital from the area with a population of 84 000 children in 1991–2009. Results: The annual incidence of parapneumonic empyema was 1.6/100 000 children in 1991–1998, 0.2/100 000 children in 1999–2005 and 2.7/100 000 children in 2006–2009. Bacterial aetiology was identified in 52% of the cases, and pneumococcus caused 45% of the cases with bacterial aetiology detected. The clinical and laboratory findings in children with and without pleural effusion on admission were surprisingly similar. The development of empyema in hospital during antibiotic therapy was associated with persistent fever and serum C‐reactive protein (CRP) >200 mg/L for 48 h after admission. Conclusion: The incidence of parapneumonic empyema in children fluctuated but in the long run, increased in 1991–2009. Pneumococcus caused half of the cases with bacterial diagnosis available. Since 2010, pneumococcal vaccination has belonged to the general vaccination programme, and the effect on the incidence of empyema remains to be seen.