Carbapenem-resistant Enterobacteriaceae reported to the National Healthcare Safety Network multidrug-resistant organism module, January 2013–December 2015

Background: Surveillance for carbapenem-resistant Enterobacteriaceae (CRE) is critical for limiting their spread. The National Healthcare Safety Network (NHSN) multidrug-resistant organism (MDRO) module laboratory-identified event (LabID) option is available for CRE clinical culture surveillance. We describe CRE reported via this module and characterize the burden of facility reporting.

Methods: We analyzed CRE reported by short-stay acute care general hospitals performing facility-wide inpatient LabID surveillance during January 1, 2013-December 31, 2015. During 2013-14, CRE were defined as Klebsiella oxytoca, Klebsiella pneumoniae or Escherichia coli, non-susceptible to imipenem, meropenem, or doripenem. In 2015, CRE were defined as any of these organisms or Enterobacter spp. resistant to any carbapenem, including ertapenem, or with a carbapenemase present. We evaluated characteristics of patients and reporting facilities and calculated the mean monthly facility CRE rate.

Results: Over the 3 years, events were reported from 342 facilities (170 [50%] teaching, 88% ≤500 beds) in 22 states. There were 10927 events in 8252 patients (4168 [51%] female, median age 69 years [range <1-110]). Among events, 9220 (84%) were Klebsiella spp., 990 (9%) E.coli, and 717 (7%) Enterobacter spp; 5510 (50%) events were hospital-onset. In 2015, when all 3 genera were reported, there were 3641 (76%) Klebsiella spp., 411 (9%) E. coli, and 717 (15%) Enterobacter spp. During 2013-14, the mean CRE rate was 0.66 events/facility-month (range 0-14.44); for 2015, the rate was 0.73 events/facility-month (range 0-13.08). Among facilities reporting ≥6 months of data in 2015 (269), 175 (65%) reported ≤1 CRE per month. Among states with mandatory CRE reporting during 2013-15 and ≥1 year of data in the MDRO module (n=3), the overall mean facility CRE event rate was 0.55 events/month; rates by state were 0.08, 0.08, and 1.5.

Conclusion: The majority of facilities performing surveillance via the MDRO module reported ≤1 CRE a month, highlighting the limited burden of CRE reporting. However, facility rates varied nearly twenty-fold among states with mandatory reporting. This heterogeneity demonstrates the importance of surveillance in targeting prevention strategies.