Is surveillance for multidrug-resistant enterobacteriaceae an effective infection control strategy in the absence of an outbreak?

Multidrug-resistant enterobacteriaceae (MDRE) are an important cause of nosocomial infections. The effectiveness of screening for MDRE in the nonoutbreak setting in an attempt to prevent transmission is unknown. Patients admitted for new organ transplantation were screened for MDRE colonization. Prospective clinical data were collected, and pulsed-field gel electrophoresis and plasmid and integron analysis of isolates were performed. Colonized patients were not isolated except when required by standard precautions. Of the 287 patients, 69 (24%) were colonized, and 6 (9%) of the 69 developed clinical infections. Most colonizing isolates (66/69) were unique. No clinical infections resulted from patient-to-patient transmission. Analysis of clinical isolates from nonstudy patients demonstrated no evidence of transmission leading to clinical disease. The annual cost of a surveillance program was calculated at Canadian $1,130,184.44. Thus, the routine and costly use of MDRE surveillance and isolation precautions are not warranted in the absence of a clonal outbreak in this population.