The epidemiology of vancomycin resistant enterococcus (VRE); The first 1044 isolates

VRE are concerning nosocomial pathogens because of the limited therapeutic options and the potential to transfer the resistance genes to methicillin-resistant Staphylococcus aureus. Between 1989 and 1996, we maintained a database which includes demographic and clinical data on all JHH patients with VRE colonization or infection (C/I). VRE culture rates increased from 0.90/1000 patient discharges (pdc) in 1989 to 7.3/1000 pdc in 1996. The most significant increases have occurred on the solid organ transplant and the pediatric services. Among the first 1044 patients who developed VRE C/I; 22% were in intensive care units, 9% on oncology wards, 3% on pediatric wards, and 4% on solid organ transplant service. Over 50% of patients were housed on medical and surgical wards. Cases were distributed throughout the year with increases in the spring (March-May) and the fall (October-December). Sites of VRE C/I include: urine (36%), stool (10%), surgical wound (10%), bile (8%), blood (BSI) (7%), sputum (6%), IV catheter (3%) and other (19%). Pulse field gel electrophoresis of the chromosomal DNA obtained in 1996 isolates revealed that 50% of VRE isolates have unique banding patterns. 44% of patients received vancomycin prior to the VRE isolate, while 94% had received cephalosporins, 52% had received metronidazole, 54% had received aminoglycoside antibiotics. In 1995, the number and rates of new VRE cases and BSI among hospitalized patients decreased slightly from 1994 (6.4 to 5.7/1000 pdc, 36 to 24 BSI per year, respectively). Ticarcillin/ clavulanic acid was on the JHH formulary between late 1994 and February 1996. Since the drug was removed from the formulary, VRE rates among patients increased significantly (7.3/1000 pdc and 40 BSI) despite heightened awareness of the problem, increased isolation procedures and better mechanisms to identify and quickly isolate patients known to be colonized with VRE. Control of VRE C/I will require infection and antibiotic control.