The role of viridans streptococci and anaerobic bacteria of the oral cavity in paediatric parapneumonic pleural effusions/empyema-a nationwide hospital-based surveillance study.

OBJECTIVES

Parapneumonic pleural effusions/empyema (PPE/PE) are serious complications of community-acquired pneumonia in children. Although Streptococcus pneumoniae and Streptococcus pyogenes are established major pathogens, the clinical relevance of oral cavity bacteria (viridans streptococci and/or anaerobic bacteria [VS/AA]) in paediatric PPE/PE is largely unclear.

METHODS

A nationwide hospital-based surveillance study in Germany recorded children aged <18 years with PPE/PE from October 2010 to June 2023, with bacteria detected from pleural fluid and/or blood. We compared clinical characteristics of patients with VS/AA-associated PPE/PE with those of patients with S. pneumoniae- or S. pyogenes-associated PPE/PE (reference group) using multivariable regression analysis, with results presented as regression coefficient (RC) or OR with 95% CI, respectively.

RESULTS

Among 1242 children with any identified PPE/PE-associated pathogen, 115 (9.3%) presented with VS/AA and 818 (65.9%) with S. pneumoniae or S. pyogenes. Compared with the reference group, children with VS/AA-associated PPE/PE were older (median [interquartile range]: 11.4 [4.9-14.9] vs. 3.6 [2.2-5.7] years, p < 0.001) and had more underlying diseases (46.1% [53/115] vs. 22.2% [182/818], p < 0.001), mainly complex neurological comorbidities (25.2% [29/115]). In multivariable analyses, VS/AA vs. reference patients showed a similar duration of hospital stay (median [interquartile range]: 20 days [15-28] vs. 18 days [14-25], p 0.467), and a similar proportion required treatment at a paediatric intensive care unit (80.0% [92/115] vs. 81.5% [667/818], p 0.992). VS/AA patients had a longer time from symptom onset to hospital admission or to discharge (by 4.1 days [RC, 95% CI 2.5-5.7, p < 0.001] and by 5.2 days [RC, 95% CI 2.1-8.3, p 0.001], respectively) and needed longer paediatric intensive care unit treatment (by 3.1 days, [RC, 95%CI 0.4-5.9, p 0.025]). They showed more frequent pulmonary complications, especially atelectasis (65.2% [75/115] vs. 50.6% [414/818]; OR 1.9, 95% CI 1.2-3.0, p 0.006) and pulmonary abscess (27.8% [32/115] vs. 19.8% [162/818]; OR 1.7, 95% CI 1.0-2.8, p 0.040). They were more likely to develop sequelae (41.6% [47/115] vs. 21.3% [173/818]; OR 2.3, 95% CI 1.5-3.7, p < 0.001) but less likely to develop sepsis/systemic inflammatory response syndrome (8.7% [10/115] vs. 18.1% [148/818]; OR 0.4, 95% CI 0.2-0.7, p 0.004).

CONCLUSIONS

VS/AA-associated PPE/PE particularly affected older children and those with complex comorbidities. In such patients, it would therefore be advisable to include anaerobic coverage in empirical antibiotic treatment, and distinct clinical features should be considered in therapeutic management.