Streptococcus bovis bacteremia as a Complication of Colonoscopy

Abstract

Purpose: Infectious complications of colonoscopy are uncommon. The most common type is bacteremia, which is usually transient and does not cause symptoms. The most common organisms causing bacteremia are the indigenous gut flora. Streptoccus bovis is one of the normal inhabitants of the human gastrointestinal tract. Reported cases of Streptococcus bovis bacteremia are usually in association with colon cancer or infective endocarditis, although there are also reports that suggest that it may occur in association with adenomatous colon polyps. We report a case of a patient who has no colon cancer or endocarditis and who developed symptomatic Streptococcus bovis bacteremia after colonoscopy and polypectomy. A 59 year old Caucasian male underwent routine colonoscopy for colorectal cancer screening. His past medical history includes chronic atrial fibrillation, diabetes mellitus and aortic stenosis. Findings on colonoscopy include four polyps, varying in size from 6 to 8 mm, which were all removed by snare cautery and hot biopsy forceps. All of these polyps were adenomas. Less than twenty four hours after colonoscopy, the patient developed high grade fever and chills. He was then admitted to the hospital. WBC count on admission was 11.9 thousand/cubic mm. Initial fever workup, including chest x-ray, urinalysis and urine culture, was unremarkable. Subsequently, Streptococcus bovis grew in the blood cultures. A transesophageal echocardiogram was done, which did not show any findings to suggest endocarditis. The patient was treated with intravenous Levofloxacin based on the sensitivity in the blood cultures. The patient's recovery was uneventful. The reported incidence of bacteremia after colonoscopy varies from 0% to 25%, with a mean frequency of 4.4%. It is postulated that mucosal trauma related to the procedure allows translocation of the normal gut flora into the bloodstream. Other factors that predispose to bacteremia include the degree of distension of the colon and the colon-cleansing method. Streptococcus bovis is a non-enterococcal group D streptococcus in the human gastrointestinal tract that can cause bacteremia and endocarditis. The association between Streptococcus bacteremia and colonic neoplasia is well-described. There are also several studies showing the relationship between Streptococcus bovis bacteremia and other non-malignant gastrointestinal diseases, including colonic adenomas. In our case, the patient did not have colon cancer or endocarditis but he had several adenomatous colon polyps. The combination of mucosal trauma from colonoscopy and the presence of colonic adenomas most likely contributed to the development of Streptococcus bovis bacteremia in this patient.