Infective Endocarditis (Pediatric)

Definition

Infective endocarditis (IE) in children is an infection of the endocardial surface of the heart, usually affecting heart valves, caused by bacteria or fungi, leading to vegetation formation, valvular dysfunction, and systemic embolization.

Epidemiology

• Rare in children, incidence approximately 0.43–0.69 per 100,000 children per year
• Higher risk in children with congenital heart disease or prosthetic heart valves
• Increased risk in immunocompromised children or those with indwelling central lines
• Male predominance observed in pediatric cases
• Neonatal IE is uncommon but carries high morbidity

Etiology

• Bacterial pathogens: Staphylococcus aureus, Streptococcus viridans group, Enterococcus species
• Fungal pathogens: Candida, Aspergillus (rare, usually in immunocompromised)
• Congenital heart defects: ventricular septal defect, tetralogy of Fallot, patent ductus arteriosus
• Prosthetic heart valves or prior cardiac surgery
• Indwelling intravascular catheters or devices
• Rheumatic heart disease or acquired valvular lesions (less common in developed countries)

Pathophysiology

• Endothelial damage on valves or endocardium facilitates bacterial adhesion
• Platelet and fibrin deposition forms a nidus for microbial colonization
• Vegetation formation leads to local tissue destruction and valvular dysfunction
• Systemic embolization of vegetations can cause infarcts or abscesses
• Immune complex deposition may cause glomerulonephritis
• Persistent bacteremia leads to systemic inflammatory response and sepsis