[Endocarditis caused by group B streptococci in adults]

Abstract

Objective: To evaluate clinical characteristics, treatment and outcome of group B streptococcal endocarditis in nonpregnant adults.

Methods: We included all cases of Streptococcus agalactiae endocarditis diagnosed according to the Duke criteria between 1980 and 1994 in a 1000-bed university hospital, where a prospective surveillance of all cases of bacteremia is regularly performed.

Results: There were 9 episodes of S. agalactiae endocarditis, that account for the 10.5% of 85 bacteremia caused by this organism and 2.6% of 336 infectious endocarditis (in non-drug abusers) during the study period. They occurred in 6 males and 3 females with an average age of 60 years (44-86 years). Three patients had underlying disease and three had been previously diagnosed of having valvulopathy. There were no cases of prosthetic valve endocarditis. The valves most frequently involved were the aortic and mitral valves. Only one patient had large vessel embolization. All isolates were penicillin-susceptible (MIC < 0.12 microgram/ml). Most of the patients were treated with penicillin plus an aminoglycoside and 6 patients also underwent surgery combined with the medical therapy after an average of 40 days (13-60 days). The overall mortality was 11%.

Conclusions: S. agalactiae is a rare cause of infectious endocarditis. Combination of surgery with the antibiotic therapy might decrease mortality rates of this infection.