The increasing incidence of childhood empyema thoracis :epidemiology and clinical aspects

Abstract

Historically, empyema thoracis has been a major cause of morbidity and mortality in children. It became the focus of considerable attention following its resurgence globally in the 1990’s. The factors driving this change remain uncertain. In addition, there remains significant controversy over the best method of management of the condition. This thesis aimed to define the epidemiology of paediatric empyema thoracis, to understand the factors contributing to the rise in the incidence of the disease. Secondary aims included investigation of the impact of the pneumococcal conjugate vaccine on paediatric empyema and evaluation of the effectiveness of different treatment methodologies in the condition. A progressive framework of multivariate time series models and wavelet analysis was used to investigate relationships between empyema and pneumonia, activity of Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes and Mycoplasma pneumoniae and time. The spatial epidemiology of the both conditions in North East England was defined and the impact of the introduction of routine pneumococcal vaccination investigated using an interrupted time series analysis. Multivariate survival models were used to investigate outcomes following different treatment methods. Hospitalisations due to empyema increased significantly in England between 1997 and 2006, underpinned by an increase in bacterial pneumonia. Isolations of S. pneumoniae and S. pyogenes were positive predictors of empyema nationally. No spatial variation in the risk of empyema was detected. Introduction of pneumococcal vaccination did not decrease empyema hospitalisations. Children who underwent primary surgical treatment for their empyema had a 40% reduction in hospital stay and a lower risk of readmission or of any complication. The increase in the incidence of paediatric empyema in England was driven predominantly by an increase in pneumococcal and streptococcal pneumonia. Primary surgery in empyema allowed earlier discharge, but further research is needed to establish which outcomes are most acceptable to patients and their families.