Purpose: We investigated the clinical features of Bacteroides bacteremia for 5 years to determine the risk factors for mortality and to ascertain whether bacteremia due to Bacteroides spp. is associated with colorectal carcinoma.
Methods: This study comprised a review of all patients with Bacteroides bacteremia at a teaching hospital in Tokyo from April 2003 to March 2008. We also conducted a case-control study between Bacteroides bacteremia and bacteremia due to other pathogens.
Results: During the study period, 25 cases of bacteremia were due to Bacteroides spp. Bacteroides bacteremia was associated with a high mortality rate (24%). Malignancy (76%) was the major comorbidity, followed by a history of surgery (40%). Colorectal carcinoma was the most frequent (n = 8, 32%) of the comorbid malignancies and was recognized as the primary infection site in six cases. Prevalence of colorectal carcinoma as comorbidity was significantly higher in Bacteroides bacteremia than in other bacteremia.
Conclusions: In the Bacteroides bacteremia cases of this study, colorectal carcinoma was the major comorbidity and primary infection site. Colorectal carcinoma screening in Bacteroides bacteremia patients is potentially an important diagnostic marker for the early detection of this infection in the future.