Endocarditis due to group A streptococcus.

In a prospective 30-month study 85 cases of endocarditis were observed at Harlem Hospital Center. Seven were due to group A beta-hemolytic streptococcus. Six of the seven were heroin users in whom solitary tricuspid valve infection occurred. Aortic valve infection occurred in the remaining patient. An incidence of 8% of group A streptococcal endocarditis was observed. An unusual local frequency of 14% of group A endocarditis among heroin addicts was noted.