infection control and hospital epidemiology june 2010, vol. 31, no. 6 original article Potential Role of Active Surveillance in the Control of a Hospital-Wide Outbreak of Carbapenem-Resistant Klebsiella pneumoniae Infection Debby Ben-David, MD; Yasmin Maor, MD; Nathan Keller, MD; Gili Regev-Yochay, MD; Ilana Tal, MS; Dalit Shachar, RN; Amir Zlotkin, PhD; Gill Smollan, MD; Galia Rahav, MD background. The recent emergence of carbapenem resistance among Enterobacteriaceae is a major threat for hospitalized patients, and effective strategies are needed. objective. To assess the effect of an intensified intervention, which included active surveillance, on the incidence of infection with carbapenem-resistant Klebsiella pneumoniae. setting. Sheba Medical Center, a 1,600-bed tertiary care teaching hospital in Tel Hashomer, Israel. design. Quasi-experimental study. methods. The medical records of all the patients who acquired a carbapenem-resistant K. pneumoniae infection during 2006 were reviewed. An intensified intervention was initiated in May 2007. In addition to contact precautions, active surveillance was initiated in high-risk units. The incidence of clinical carbapenem-resistant K. pneumoniae infection over time was measured, and interrupted time- series analysis was performed. results. The incidence of clinical carbapenem-resistant K. pneumoniae infection increased 6.42-fold from the first quarter of 2006 up to the initiation of the intervention. In 2006, of the 120 patients whose clinical microbiologic culture results were positive for carbapenem- resistant K. pneumoniae, 67 (56%) developed a nosocomial infection. During the intervention period, the rate of carbapenem-resistant K. pneumoniae rectal colonization was 9%. Of the 390 patients with carbapenem-resistant K. pneumoniae colonization or infection, 204 (52%) were identified by screening cultures. There were a total of 12,391 days of contact precautions, and of these, 4,713 (38%) were added as a result of active surveillance. After initiation of infection control measures, we observed a significant decrease in the incidence of carbapenem- resistant K. pneumoniae infection. conclusions. The use of active surveillance and contact precautions, as part of a multifactorial intervention, may be an effective strategy to decrease rates of nosocomial transmission of carbapenem-resistant K. pneumoniae colonization or infection. Infect Control Hosp Epidemiol 2010; 31(6):620-626 From the Infectious Diseases Unit, Sheba Medical Center, Tel Hashomer, Israel (all authors). Received September 5, 2009; accepted December 4, 2009; electronically published April 6, 2010.  2010 by The Society for Healthcare Epidemiology of America. All rights reserved. 0899-823X/2010/3106-0010$15.00. DOI: 10.1086/652528 The spread of carbapenem resistance among Enterobacte- riaceae is mediated by the Klebsiella pneumoniae carbape- nemase (KPC) and represents an emerging threat because Enterobacteriaceae are resistant to almost all available an- timicrobial agents and spread rapidly. Since the first de- scription of carbapenem-resistant K. pneumoniae in North Carolina in 2001, 1 a number of outbreaks of infection have been reported. 2-6 In a report from New York City, carba- penem-resistant K. pneumoniae accounted for one-quarter of all invasive K. pneumoniae infections during a period of 2 years. 7 Infections due to carbapenem-resistant K. pneumoniae are associated with increased morbidity and mortality. 7,8 Pa- tients with an infection caused by carbapenem-resistant K. pneumoniae were 3 times more likely to die during their hospital stay, compared with patients with an infection caused by a susceptible strain. 7 Despite growing concern about the emergence of carbapenem-resistant K. pneumoniae, optimal strategies for preventing its spread in a healthcare facility are unknown. Reports of the successful containment of outbreaks of carbapenem-resistant K. pneumoniae infection are rare. 9 In 2006, carbapenem-resistant K. pneumoniae spread in several acute care facilities in Israel, 3,10 causing several hun-