An unusual case of Streptococcus pyogenes infective endocarditis demonstrating the usefulness of repeated echocardiography

Abstract

Infective endocarditis (IE) is most often caused by alpha-hemolytic streptococci or Staphylococcus aureus and is characterized by the presence of vegetations on the heart valves. Here we present a case of IE caused by Streptococcus pyogenes, a distinctly uncommon IE-pathogen, where no vegetations could be visualized on repeated echocardiography. Diagnosis was instead evident from septic embolizations and progressive aortic insufficiency and IE was verified upon heart valve surgery. The patient was a 69-year-old man who presented with a two-day-history of fever and confusion. Several lesions on the skin and in the brain were suggestive of septic embolization and blood cultures grew S. pyogenes of sequence type 39, emm4. The patient developed progressive aortic insufficiency and was subjected to surgery at day seven after admittance. The aortic cusp showed signs of destructive IE and analysis of the valve demonstrated the presence of DNA from S. pyogenes ultimately confirming the diagnosis. The patient received a biological heart valve prosthesis and needed medical treatment for atrial fibrillation and heart failure post operatively. There was no relapse at six months post-surgery.