Early Cessation of a Vancomycin-Resistant Enterococci (VRE) Outbreak in a Hematology-Oncology Department after Implementation of an Enhanced Infection Control Intervention. A Single Center Experience.

Introduction: Worldwide, the incidence of nosocomial outbreaks of VRE has increased especially in high-risk patients such as hematology-oncology patients. Outbreaks reported so far, required a minimum of three months to be controlled. Such outbreaks have a serious impact on daily care and treatment of the patients and hospital economics.

Patients and Methods: We describe the outcome of a VRE-outbreak in a department with 48 beds (fourteen 2-patient rooms, and 20 single-patient rooms) including allogeneic BMT. Epidemiological evaluation was initiated after two patients in the department for the first time had a blood stream infection (BSI) with VRE within one week. Two goals had to be achieved immediately: 1) Assessment of the outbreak and 2) Implementation of enhanced infection control measures. Screening of all inpatients on a weekly basis became mandatory (stool sample or rectal swab). All patients, regardless of their status, received a single-patient room and had their own assigned restroom. Therefore an additional ward had to be opened. The patients and staff were re-trained in hygiene rules and contact precautions. Positive VRE-tested patients were cohorted in one ward. In addition, spot screening was performed in the outpatient clinic. Due to a low number of restroom facilities and patient rooms, the outpatient clinic was closed for new admissions and reopened within 6 weeks at a new site with improved facilities and more patient rooms. Antibiotic usage was reviewed. Utilization of glycopeptides and cephalosporins was decreased. Pulsed-field gel electrophoresis (PFGE) was performed on all isolates. The outbreak was actively discussed in the local newspapers and television to inform the public of the situation.

Results: This is the largest VRE-outbreak in a hematology-oncology department reported to date. Four-hundred-seventy-five patients were evaluated and 1246 tests were performed, resulting in a mean test frequency of 2.6 tests per patient. In this patient population, 34 VRE-colonized patients were identified, 18 within the first 4 weeks of screening. From January through April 2004, a total of 31 VRE-colonized patients were detected. Two additional VRE-BSI occurred. All patients with VRE-BSI were treated successfully with linezolid. PFGE demonstrated a dominant clone indicating a nosocomial transmission mode. After the opening of the new outpatient clinic and normalization of admission policies on the inpatient wards [the extra ward was closed and ID control measures stayed in effect] only 3 additional VRE-colonized patients were detected but PFGE demonstrated different clones. Cutting down on new admissions and actively discussing the outbreak in public was rewarded with back-to-baseline admissions after cessation of the outbreak.

Conclusion: Though VRE-infections nowadays can easily be treated with linezolid, its detection indicates an infection control problem. Awareness of the development of resistant microbes especially in the immunocompromised setting requires pragmatic and stringent ID control measures to prevent or to cease early an outbreak of this magnitude.