Risk of Infective Endocarditis in Pediatric Staphylococcal Bacteremia: A 20-Year Cohort Study

OBJECTIVE: The prevalence of Staphylococcus aureus endocarditis (SAE) in children with S. aureus bacteremia (SAB) varies widely and is generally lower than that in adults. This study aimed to determine the prevalence of SAE in pediatric patients with SAB and to identify the associated clinical risk factors. METHODS: This retrospective study included all children aged 0-18 years diagnosed with SAB at a university hospital in Thailand between 2003 and 2023, identified using International Statistical Classification of Diseases and Related Health Problems 10th Revision codes. Endocarditis was defined using the modified Duke criteria, in accordance with the 2023 European Society of Cardiology guidelines for the management of endocarditis. RESULTS: Among the 171 children with SAB, 15 (8.8%) met the criteria for definite infective endocarditis. Methicillin-sensitive S. aureus was the predominant pathogen in both uncomplicated SAB and SAB complicated by endocarditis. Congenital heart disease was significantly associated with SAE (P = 0.02). Additional risk factors included protein-energy malnutrition (PEM) (P = 0.04) and more than 2 positive blood cultures (P = 0.001), whereas immunocompromised status was associated with a reduced risk (P < 0.001). Both SAB and SAE were associated with prolonged hospitalization and increased mortality. CONCLUSIONS: SAE occurred in 8.8% of pediatric SAB cases. Congenital heart disease, protein-energy malnutrition and persistent bacteremia were key predictors of SAE. In settings where echocardiography is not immediately accessible, these clinical risk factors can guide the early identification of high-risk patients and support decisions regarding monitoring intensity and timely referral. Larger prospective studies are needed to validate these associations and to facilitate the development of practical prediction tools for pediatric SAE.