title: Viridans streptococcal endocarditis: clinical, microbiological, and echocardiographic correlations.
abstract: Infections caused by species within the viridans streptococci have been associated with different clinical characteristics. We studied 36 patients with viridans streptococcal endocarditis. Complications were seen in 10 (32%) of 31 patients with native valve endocarditis and four (80%) of five with prosthetic valve endocarditis and included death in two, valve replacement in six, persistent infection in three, emboli in two, and congestive heart failure in nine. Two-dimensional echocardiograms demonstrated vegetations in 26 (72%) of 36, flail mitral valves in seven, disruption of aortic valve prosthesis in one, and perivalvular abscesses in three (two Streptococcus sanguis I and one Streptococcus intermedius I). All twelve patients with native valve endocarditis who suffered complications had vegetations detected by two-dimensional echocardiography, whereas seven patients with native valve endocarditis without vegetations, as detected by two-dimensional echocardiography, had no complications (P = .03). We found no significant correlation between streptococcal species and clinical outcome. To confirm our identifications, we sent 16 identical viridans streptococcal endocarditis isolates to five institutions; only three of 16 were identified as the same species by all five institutions. We conclude that viridans streptococcal endocarditis can be associated with a virulent clinical course and that there is marked variability in species designations of individual strains by different laboratories.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D004697:Endocarditis, Bacterial / Q000150:complications / Q000382:microbiology*; D005260:Female; D006333:Heart Failure / Q000209:etiology; D006349:Heart Valve Diseases / Q000150:complications / Q000382:microbiology*; D006350:Heart Valve Prosthesis; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D013290:Streptococcal Infections / Q000150:complications / Q000382:microbiology*; D013291:Streptococcus / Q000145:classification / Q000302:isolation & purification; D013298:Streptococcus sanguis / Q000145:classification / Q000302:isolation & purification