Culture Negative Left Sided Endocarditis and Immune Mediated Acute Kidney Injury Following Covid 19 in Previously Healthy Sixteen-Month-Old Female Child

Background: Infective endocarditis (IE) in children is rare, particularly in those without congenital heart disease or chronic comorbidities. Post–COVID-19 immune dysregulation has emerged as a potential contributor to unusual cardiovascular complications. Case Presentation: We report a 16-month-old previously healthy female child presenting with recurrent fever, respiratory distress, and hypoxemia. Initial imaging revealed pulmonary edema and hemorrhage. Echocardiography demonstrated a mitral valve vegetation with moderate regurgitation, and a diagnosis of IE was made despite persistently negative blood cultures. Her course was complicated by acute kidney injury due to immune complex–mediated glomerulonephritis, requiring peritoneal dialysis, and by an embolic ischemic stroke confirmed on MRI. Inflammatory and thrombotic markers were markedly elevated, consistent with post–COVID-19 immune activation. Despite optimal medical therapy, the vegetation enlarged with progression to severe mitral regurgitation. Surgical removal of the vegetation and mitral valve repair were performed successfully, with subsequent clinical stabilization.
Conclusion: This case highlights culture-negative IE in a previously healthy child in the setting of post–COVID-19 immune dysregulation. Early recognition of complications, multidisciplinary management, and timely surgical intervention were crucial for a favourable outcome.