Epidemiology of Carbapenem-Resistant Enterobacteriaceae in 7 US Communities, 2012-2013
Authors: Alice Y. Guh, Sandra N. Bulens, Yi Mu, Jesse T. Jacob, Jessica Reno, Janine Scott, Lucy E. Wilson, Elisabeth Vaeth, Ruth Lynfield, Kristin M. Shaw, Paula M. Snippes Vagnone, Wendy M. Bamberg, Sarah J. Janelle, Ghinwa Dumyati, Cathleen Concannon, Zintars Beldavs, Margaret Cunningham, P. Maureen Cassidy, Erin C. Phipps, Nicole Kenslow, Tatiana Travis, David Lonsway, J. Kamile Rasheed, Brandi M. Limbago, Alexander J. Kallen
Journal: JAMA (2015)

Carbapenem-resistant Enterobacteriaceae (CRE) are increasingly reported worldwide as a cause of infections with high-mortality rates. Assessment of the US epidemiology of CRE is needed to inform national prevention efforts.To determine the population-based CRE incidence and describe the characteristics and resistance mechanism associated with isolates from 7 US geographical areas.Population- and laboratory-based active surveillance of CRE conducted among individuals living in 1 of 7 US metropolitan areas in Colorado, Georgia, Maryland, Minnesota, New Mexico, New York, and Oregon. Cases of CRE were defined as carbapenem-nonsusceptible (excluding ertapenem) and extended-spectrum cephalosporin-resistant Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae complex, Klebsiella pneumoniae, or Klebsiella oxytoca that were recovered from sterile-site or urine cultures during 2012-2013. Case records were reviewed and molecular typing for common carbapenemases was performed.Demographics, comorbidities, health care exposures, and culture source and location.Population-based CRE incidence, site-specific standardized incidence ratios (adjusted for age and race), and clinical and microbiological characteristics.Among 599 CRE cases in 481 individuals, 520 (86.8%; 95% CI, 84.1%-89.5%) were isolated from urine and 68 (11.4%; 95% CI, 8.8%-13.9%) from blood. The median age was 66 years (95% CI, 62.1-65.4 years) and 284 (59.0%; 95% CI, 54.6%-63.5%) were female. The overall annual CRE incidence rate per 100<000 population was 2.93 (95% CI, 2.65-3.23). The CRE standardized incidence ratio was significantly higher than predicted for the sites in Georgia (1.65 [95% CI, 1.20-2.25]; P < .001), Maryland (1.44 [95% CI, 1.06-1.96]; P = .001), and New York (1.42 [95% CI, 1.05-1.92]; P = .048), and significantly lower than predicted for the sites in Colorado (0.53 [95% CI, 0.39-0.71]; P < .001), New Mexico (0.41 [95% CI, 0.30-0.55]; P = .01), and Oregon (0.28 [95% CI, 0.21-0.38]; P < .001). Most cases occurred in individuals with prior hospitalizations (399/531 [75.1%; 95% CI, 71.4%-78.8%]) or indwelling devices (382/525 [72.8%; 95% CI, 68.9%-76.6%]); 180 of 322 (55.9%; 95% CI, 50.0%-60.8%) admitted cases resulted in a discharge to a long-term care setting. Death occurred in 51 (9.0%; 95% CI, 6.6%-11.4%) cases, including in 25 of 91 cases (27.5%; 95% CI, 18.1%-36.8%) with CRE isolated from normally sterile sites. Of 188 isolates tested, 90 (47.9%; 95% CI, 40.6%-55.1%) produced a carbapenemase.In this population- and laboratory-based active surveillance system in 7 states, the incidence of CRE was 2.93 per 100<000 population. Most CRE cases were isolated from a urine source, and were associated with high prevalence of prior hospitalizations or indwelling devices, and discharge to long-term care settings.