Proactive infection control measures to prevent nosocomial transmission of carbapenem-resistant Enterobacteriaceae in a non-endemic area

Background Identification of hospitalized carbapenem-resistant Enterobacteriaceae (CRE)-positive patient is important in preventing nosocomial transmission. The objective of this study was to illustrate the implementation of proactive infection control measures in preventing nosocomial transmission of CRE in a healthcare region of over 3200 beds in Hong Kong between October 1, 2010 and December 31, 2011. Methods The program included active surveillance culture in patients with history of medical tourism with hospitalization and surgical operation outside Hong Kong within 12 months before admission, and "added test" as an opportunistic CRE screening in all fecal specimens submitted to the laboratory. Outbreak investigation and contact tracing were conducted for CRE-positive patients. Serial quantitative culture was performed on ORE-positive patients and the duration of fecal carriage of CRE was analyzed. Results During the study period, a total of 6533 patients were screened for ORE, of which 76 patients were positive (10 from active surveillance culture, 65 from "added test", and 1 secondary case from contact tracing of 223 patients with no nosocomial outbreak), resulting in an overall rate of ORE fecal carriage of 1.2%. The median time of fecal carriage of ORE was 43 days (range, 13-119 days). Beta-lactam-beta-lactamase-inhibitors, cephalosporins, and fluoroquinolones were associated significantly with high fecal bacterial load when used 90 days before ORE detection, while use of cephalosporins, carbapenems, and fluoroquinolones after ORE detection are significantly associated with longer duration of carriage. The duration of fecal carriage of ORE also correlates significantly with the initial fecal bacterial load (Pearson correlation: 0.53; P=0.02). Conclusion Proactive infection control measures by enhanced surveillance program identify ORE-positive patients and data obtained are useful for the planning of and resource allocation for ORE control.