Incidence, Clinical Features, Risk Factors and Outcome of Bacteremia due to Vancomycin-Resistant and Vancomycin-Sensitive Enterococcus Species Analyzed Over a 7-year Period in a Single Cancer Institution

The aim of this study was to retrospectively compare the incidence, risk factors, and outcome in patients seen over a 7-year period at the National Cancer Institute in the Slovak Republic, with vancomycin-sensitive or vancomycin-resistant enterococcal bacteremia. The total incidence of enterococcal bacteremia at the National Cancer Institute increased from 5.1% in 1991 to 11.1% in 1993 and then decreased to 4.3% in 1995. Analysis of the 77 episodes of enterococcal bacteremia from 66 patients showed that 69 episodes from 60 patients were due to vancomycin-sensitiveEnterococcus faecalis (group 1) and 8 episodes from 8 patients were due to vancomycin-resistantEnterococcus faecium (group 2). The features most frequently associated with enterococcal bacteremia were the insertion of a central venous catheter, neutropenia lasting more than 10 days, previous therapy with cephalosporins or vancomycin, previous prophylaxis with quinolones, and the incidence of superinfections. There was no difference in the clinical course or outcome between the 2 study groups. Previous therapy with aminoglycosides, cephalosporins, vancomycin or imipenem, neutropenia less than 10 days in length, malignancies other than leukemia or solid tumors, and the incidence of breakthrough bacteremia significantly correlated with patients with vancomycin-resistantE. faecium rather than patients with vancomycin-sensitiveE. faecalis. The overall mortality was similar in both groups and averaged 32.5% for all enterococcal bacteremic patients. In this study, the major risk factors associated with cancer patients for developing vancomycin-resistant enterococcal bacteremia were previous therapy with aminoglycosides, cephalosporins or vancomycin, superinfections with other organisms and the incidence of breakthrough bacteremia.