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 with
Streptococcus pneumoniae
(
S pneumoniae
) 1.2% (0.8–1.6) and
Spyogenes
1.9% (0.9–3.3). An intermediary IE prevalence was found with
Sanginosus
4.8% (3.0–7.3),
Ssalivarius
5.8% (2.9–10.1), and
Sagalactiae
9.1% (6.6–12.1). The highest IE prevalence was found with
Smitis/oralis
19.4% (15.6–23.5),
Sgallolyticus
(formerly
Sbovis
) 30.2% (24.3–36.7),
Ssanguinis
34.6% (26.6–43.3),
Sgordonii
44.2% (34.0–54.8), and
Smutans
47.9% (33.3–62.8). In multivariable analysis using
S pneumoniae
as reference, all species except
S pyogenes
were associated with significantly higher IE risk, with the highest risk found with
S gallolyticus
odds ratio (OR) 31.0 (18.8–51.1),
S mitis/oralis
OR 31.6 (19.8–50.5),
S sanguinis
OR 59.1 (32.6–107),
S gordonii
OR 80.8 (43.9–149), and
S mutans
OR 81.3 (37.6–176).
Conclusions:
The prevalence of IE in streptococcal BSIs is species dependent with
S mutans, S gordonii, S sanguinis, S gallolyticus
, and
S mitis/oralis
having the highest IE prevalence and the highest associated IE risk after adjusting for IE risk factors.
