Vancomycin-resistant and vancomycin-sensitive enterococcal bacteremia: A comparison of clinical features and outcomes

Multidrug-resistant enterococcus is emerging as a major nosocomial threat in the 1990s. In 1993, 14% of enterococcal isolates from intensive care units were resistant to vancomycin (VRE). Infections caused by such isolates are often unbeatable with commonly employed antibiotics. The goal of our study was to elucidate risk factors for the development of VRE bacteremia and to better understand the morbidity and mortality associated with VRE. Chart reviews were performed on 93 hospitalized patients who acquired VRE bacteremia between 1991 and 1996. Identical data points were recorded from 101 control patients with vancomycin-sensitive enterococcal (VSE) bacteremia hospitalized during the same period. In comparison with VSE, VRE patients were more likely to be on a medical service, have a central venous catheter, and have a longer hospitalisation prior to the initial blood culture (16 vs. 24 days, p<001). VRE patients were more likely than VSE patients to have multiple enterococcal blood cultures but less likely to have polymicrobial bacteremia. Of multiple pharmaceutical agents evaluated, only prior exposure to metronidazole was more common in VRE than VSE patients (55% vs. 35%, p=.006). APACHE II scores on the day of initial culture were similar (20 in VRE cases vs. 18, p=.04), but mortality was substantially higher among VRE patients than VSE patients (45% vs. 27%, p=.007). Other factors strongly associated with mortality included time in an ICU, ventilatory support, APACHE II score, fecal incontinence, and presence of decubitus ulcers.