Two years of Population-based Surveillance for Carbapenem-resistant Enterobacteriaceae (CRE) in Bernalillo County, NM, 2014-2015

Background: Carbapenem-resistant Enterobacteriaceae (CRE) present treatment and infection control challenges. CRE can be transmitted in healthcare settings, and invasive infections can cause high mortality.

Methods: Active, laboratory- and population-based surveillance was conducted in Bernalillo County, NM. We defined CRE as Escherichia coli, Enterobacter spp, or Klebsiella spp nonsusceptible to ≥1 carbapenem (excluding ertapenem) and resistant to all 3rd generation cephalosporins tested, and CRAB as A. baumannii nonsusceptible to ≥1 carbapenem (excluding ertapenem) isolated from normally sterile sites or urine. Medical record reviews were conducted on incident cases, and a convenience sample of isolates underwent PCR for common carbapenemases at CDC.

Results: From January 1, 2014 – December 31, 2015, 85 cases were identified; half were collected in outpatient settings. Three were isolated from blood and 82 from urine. Half of the patients were aged 62 or older, and nearly three-quarters were female. Eleven percent were American Indian/Alaska Native (AIAN), twice that of the Bernalillo County population.

Two-thirds had risk factors related to healthcare exposures, indwelling devices, or travel; nearly half had been hospitalized in the prior year. A third were hospitalized at the time of, or within 30 days after culture; among those, 40% were discharged to a long-term care facility (LTCF).

Four Klebsiella pneumoniae carbapenemase (KPC)-producing organisms were identified among 48 isolates tested (8.3%): one E. aerogenes, one E. cloacae, and two K. pneumoniae. Two KPC+ specimens were collected in outpatient settings, one from a long-term acute care hospital (LTACH), and one from a LTCF. All four patients had been hospitalized in the year prior, three had been in a LTCF, and one in both a LTCF and LTACH.

Conclusion: Although the majority of isolates were collected from outpatient settings, most patients had extensive healthcare exposures in the prior year. Females and AIAN were overrepresented. Four of 48 (8.3%) of isolates submitted were carbapenemase producers; those individuals all had extensive healthcare exposures. Inter-facility communication among both inpatient and ambulatory settings is vital to limit CRE transmission.