Infective Endocarditis in a Previously Healthy Adolescent Caused by Streptococcus sanguinis: Diagnostic Challenges and Clinical Implications.

Infective endocarditis (IE) is uncommon in children, particularly in those without congenital heart disease or indwelling catheters. We describe an adolescent patient without prior history of cardiac disease or previously diagnosed predisposing conditions who developed Streptococcus sanguinis endocarditis of the native mitral valve. Despite appropriate antibiotic therapy, the clinical course was complicated by acute mitral regurgitation and heart failure requiring valve replacement. This report highlights the diagnostic and therapeutic challenges of pediatric IE in the absence of traditional risk factors and emphasizes the importance of early clinical suspicion, pathogen-directed antimicrobial therapy, and timely surgical intervention.