Risk Factors and Outcomes Associated with Non-Enterococcus Faecalis, Non-Enterococcus Faecium Enterococcal Bacteremia

Objectives: To compare risk factors, clinical features, and outcomes in patients with Enterococcus avium, Enterococcus casseliflavus, Enterococcus durans, Enterococcus gallinarum, and Enterococcus mundtii bacteremia (cases) with those in patients with Enterococcus faecalis bacteremia (controls).

Design: A retrospective case-control study.

Setting: A 725-bed, university-affiliated, academic medical center.

Patients: The clinical microbiology database at Northwestern Memorial Hospital from January 1994 to May 2003 was searched to identify cases; each case was matched to one control on the basis of date of admission.

Results: Thirty-three cases were identified and matched with 33 controls. The mean duration of hospital stay was longer (29.7 vs 17.2 days; P = .03) and the mean time to acquisition of bacteremia was greater (16.5 vs 6.3 days; P = .003) for cases than controls. Cases were more likely to have underlying hematologic malignancies (P < .001), to have been treated with corticosteroids (P = .02), and to be neutropenic (P = .003). Controls were more likely to have an indwelling bladder catheter (P = .01), and cases were more likely to have the gastrointestinal tract as a source of infection (P = .007) and to have concurrent cholangitis (P = .002). There were no differences in severity of illness or in mortality rates.

Conclusions: Compared with patients with E. faecalis bacteremia, patients with non-E. faecalis, non-Enterococcus faecium enterococcal bacteremia were more likely to have a hematologic malignancy, prior treatment with corticosteroids, neutropenia, and cholangitis; longer duration of hospital stay was also identified as a clinical feature. However, non-E. faecalis, non-E. faecium species are not associated with any differences in mortality.