Microbial Etiology of Empyema Thoracis in Children: A Systematic Review and Meta-Analysis

CONTEXT: Identifying the microbial etiology of empyema is crucial to implement contextually appropriate clinical management and prevention strategies. However, there is no systematic review examining this question. OBJECTIVE: This systematic review addressed this knowledge gap by synthesizing evidence on the pathogens identified in children with empyema. EVIDENCE ACQUISITION: PubMed, EMBASE, Cochrane Library, Scopus, Web of Science, major trial registries, and grey literature sources were searched for observational studies in children with empyema. The prevalence of organisms identified in pleural pus, blood, or bronchoalveolar lavage fluid by culture or molecular methods was determined, along with the antimicrobial susceptibility pattern. Risk of bias in the included studies was assessed using the NIH quality assessment tool for observational studies. Meta-analysis was performed using random-effects model, and the certainty of evidence was evaluated using GRADE. RESULTS: Out of 8022 citations retrieved, 36 studies were included. In pleural fluid specimens, S. aureus dominated (38.99%, 95% CI 28.97, 49.00; I2 93.5%) followed by S. pneumoniae (31.51%, 95% CI 21.75-41.26; I2 95%). In blood, S. pneumoniae was the most prevalent organism (60.05%, 95% CI 40.78-79.32; I2 93.5%) followed by S. aureus (9.51%, 95% CI 0.0-19.18; I2 73.2%). Amongst the Indian studies, S. aureus dominated both in pleural fluid and blood. Limited data suggested S. aureus and S. pneumoniae susceptibility to vancomycin, cefotaxime, and chloramphenicol. The majority of studies (n = 32) were 'fair' quality, and the GRADE certainty of evidence was 'very low'. CONCLUSION: Very low certainty evidence suggested that S. aureus and S. pneumoniae are the common causes of empyema in children, with S. aureus dominant in India.