Infective endocarditis due to Streptococcus bovis in a series of nonaddict patients: clinical and morphological characteristics of 20 cases and review of the literature.

Background And Objectives: Controversy frequently exists about the actual frequency of Streptococcus bovis infective endocarditis (IE), its incidence of malignancy and its outcome. Consequently, the characteristics of S bovis IE were examined in an unselected population of nondrug-addicted patients. The literature was also reviewed.

Methods: Nondrug-addicted patients with S bovis IE were retrospectively reviewed. Clinically definite IE was diagnosed according to the Duke classification criteria at the single reference hospital for a defined population in northwestern Spain over a 13-year period. The clinical features, need for surgery and mortality rate of these patients were compared with those of other nondrug-addicted patients with IE examined during the same time period.

Results: Between 1987 and 1999, S bovis IE was diagnosed in 20 consecutive patients. This pathogen was responsible for 16.8% of the cases of definite IE in nondrug-addicted patients. Underlying conditions and embolic septic events were common. The aortic valve was the most common site of IE. Simultaneous involvement of two cardiac valves and moderate to severe regurgitation were more common in patients with S bovis IE. Colonic neoplasms were observed in 77% of patients. However, in-hospital mortality rate, need for in-hospital surgery and surgery during follow-up did not differ between patients with S bovis IE and the other nondrug-addicted patients with IE.

Conclusions: In unselected patients, the rate of mortality due to S bovis IE is similar to that observed in IE due to other microorganisms. However, colonoscopic evaluation during admission and follow-up is required.