Increasing Rates of Pediatric Empyema and Disease Severity With Predominance of Serotype 3 S. pneumonia: An Australian Single-center, Retrospective Cohort 2011 to 2018.

Abstract

The impact of universal 13-valent pneumococcal conjugate vaccine immunization on pediatric empyema rates and pathogens in Australia is not known. We aimed to describe empyema epidemiology, clinical characteristics and treatment during an 8-year period. A retrospective study between 2011 and 2018 of empyema cases admitted to a large pediatric referral hospital, for management with either pleural drainage and fibrinolytics or surgical intervention. There were 195 cases in 8 years. Empyema incidence and ICU admission rates significantly increased during the study with a peak incidence of 7.1/1000 medical admissions in 2016 (χ for trend of incidence 37.8, P < 0.001 and for ICU admissions 15.3, P < 0.001). S. pneumoniae was the most common pathogen (75/195, 39%) with serotype 3 the most detected (27/75: 27%). S. pyogenes compared with S. pneumoniae had significantly fewer days of fever before admission (3.9 vs. 6.4, mean difference 2.4, 95% CI: 0.84-4.08, P = 0.003) and higher proportion requiring direct ICU admission (6/75; 8% vs. 7/15; 47%, P < 0.001). Compared with S. pneumoniae, cases with no pathogen detected by culture or PCR had fewer days of fever post intervention (4.4 vs. 7.4 days, mean difference 2.7 days, P = 0.002). S. aureus occurred more commonly in infants (10/25; 40% vs. 1/75; 1%, P < 0.001) and children of indigenous background (5/25; 20% vs. 1/75; 1%, P < 0.001) compared with S. pneumoniae. We report increasing rates of pediatric empyema with higher proportions requiring ICU treatment. The most common pathogens detected were S. pneumoniae, S. aureus and S. pyogenes. Despite high 13-valent pneumococcal conjugate vaccine coverage, serotype 3 was the most common S. pneumoniae serotype identified.