[Left-sided group A streptococcal endocarditis and mitral valve prolapse].

Group A beta-hemolytic streptococcus is an infrequent cause of endocarditis. Left-sided endocarditis in intravenous drug abuse is likewise uncommon; it carries a poor prognosis. A case of left-sided group A beta-hemolytic streptococcal endocarditis in a 20-year-old male drug addict with mitral valve prolapse is presented.