A Case of Culture-negative Infective Endocarditis With Atypical Presentation and Disseminated Multiorgan Embolism

Abstract

Infective endocarditis (IE) is associated with high morbidity and a mortality rate of 9-30% due to its life-threatening complications including systemic embolization of various organs. The complications are more common in culture-positive cases. In culture-negative IE, systemic embolism especially with multiorgan involvement occurring in a single patient is very rare. Such condition may significantly increase the hospital mortality and poses unique challenges in diagnosis and management. We present a case of a 14-year-old female who presented with a one-week history of vague left upper quadrant pain and fever. She had a history of recurrent mild chest pain in the last one month but did not seek any treatment. She had no risk factors of IE. On presentation, she was fully conscious but with signs of septic shock requiring vasoconstrictor support and administration of a broad-spectrum antibiotics. There was loud pansystolic murmur on auscultation and generalised abdominal tenderness. Abdominal ultrasound showed geographic hypoechogenicity of the spleen with small bowel wall thickening. Contrast-enhanced computed tomography (CECT) abdomen confirmed splenic and renal infarction with ischaemic small bowel. Transthoracic echocardiography showed vegetation at the mitral valve. She developed a severe headache during admission. CT head and conventional cerebral angiography demonstrated a ruptured mycotic aneurysm. Her CRP and ESR were elevated. Anti-DNase B Titre was elevated raising suspicion of previous group A streptococcus infection. All her blood culture results were persistently negative throughout admission possibly due to the initiation of antibiotics prior to sample collection. Despite a negative culture, she developed disseminated embolism to various organs as described. The planned mitral valve surgery was delayed due to the intracranial bleed, and she underwent craniectomy for clot removal. Mitral valve replacement was performed one month later. During follow-up, she had good recovery with no signs of heart failure or significant impairment of quality of life.