Prevalence of Infective Endocarditis in Streptococcal Bloodstream Infections Is Dependent on Streptococcal Species

Background: Streptococci frequently cause infective endocarditis (IE), yet the prevalence of IE in patients with bloodstream infections (BSIs) caused by different streptococcal species is unknown. We aimed to investigate the prevalence of IE at species level in patients with streptococcal BSIs. Methods: We investigated all patients with streptococcal BSIs, from 2008 to 2017, in the Capital Region of Denmark. Data were crosslinked with Danish nationwide registries for identification of concomitant hospitalization with IE. In a multivariable logistic regression analysis, we investigated the risk of IE according to streptococcal species adjusted for age, sex, >= 3 positive blood culture bottles, native valve disease, prosthetic valve, previous IE, and cardiac device. Results: Among 6506 cases with streptococcal BSIs (mean age 68.1 years [SD 16.2], 52.8% men) the IE prevalence was 7.1% (95% CI, 6.5-7.8). The lowest IE prevalence was found withStreptococcus pneumoniae(S pneumoniae) 1.2% (0.8-1.6) andSpyogenes1.9% (0.9-3.3). An intermediary IE prevalence was found withSanginosus4.8% (3.0-7.3),Ssalivarius5.8% (2.9-10.1), andSagalactiae9.1% (6.6-12.1). The highest IE prevalence was found withSmitis/oralis19.4% (15.6-23.5),Sgallolyticus(formerlySbovis) 30.2% (24.3-36.7),Ssanguinis34.6% (26.6-43.3),Sgordonii44.2% (34.0-54.8), andSmutans47.9% (33.3-62.8). In multivariable analysis usingS pneumoniaeas reference, all species exceptS pyogeneswere associated with significantly higher IE risk, with the highest risk found withS gallolyticusodds ratio (OR) 31.0 (18.8-51.1),S mitis/oralisOR 31.6 (19.8-50.5),S sanguinisOR 59.1 (32.6-107),S gordoniiOR 80.8 (43.9-149), andS mutansOR 81.3 (37.6-176). Conclusions: The prevalence of IE in streptococcal BSIs is species dependent withS mutans, S gordonii, S sanguinis, S gallolyticus, andS mitis/oralishaving the highest IE prevalence and the highest associated IE risk after adjusting for IE risk factors.