BACKGROUND: Carbapenem-resistant Enterobacteriaceae (CRE) are responsible for 9,000 infections and 600 deaths annually in the United States. To assess the public health importance of these infections in Connecticut, the Department of Public Health (DPH) required laboratory reporting of CRE effective January 1, 2014.
METHODS: CRE was identified as clinical isolates from the family Enterobacteriaceae obtained from any sterile site, sputum, or urine. Cases were classified as confirmed if they met the genus, clinical source, and antibiogram components of the case definition, and as suspect if they had insufficient antibiogram data. Chart review was performed for suspect and confirmed cases reported from January 1, 2014–December 31, 2015. Reports were assessed with the 2014 and the simplified 2016 case definitions to quantify any variance of case classification. Data were stored in an Access database and analyzed using SAS 9.4.
RESULTS: DPH received 296 CRE reports among 239 patients; 77% have been reviewed. Reports of non-hospitalized patients (85, 37.3%) were excluded. Of the remaining 143 (62.7%), 138 (96.5%) were classified as confirmed (112) or suspect (26). Among 126 unique patients, the median age was 72 years (range, 1–98), 64 (50.8%) were females, and 87 (69%) were White. Most CRE cases (124, 90%) were Klebsiella pneumoniae (50), Enterobacter cloacae (47), or Escherichia coli (20). Urine (63.8%) was the most common culture source followed by the respiratory tract (23.2%). Most cultures were collected in the emergency department (ED) (63, 45.7%) or in the intensive care unit (ICU) (41, 29.7%); 56 (41%) were hospitalized ≥3 days prior to culture. Most (108, 78%) had antibiotic therapy in the 60 days prior to culture; 95 (69%) had a history of ≥1 additional multidrug-resistant organisms (MDROs), and nearly 106 (77%) had ≥1 invasive devices at the time of culture. The 2014 and 2016 case definitions were applied to 144 reports with antibiogram information. The number of CRE reports classified as cases was not statistically significantly different when comparing the two case definitions.
CONCLUSIONS: Most hospitalized cases had at least one known risk factor for CRE including ≥1 additional MDROs or ≥1 invasive devices. Most cultures were collected in the ED or ICU highlighting the significance of proper communication of CRE status within and between facilities upon patient transfer. There was no difference in the case classification between the two definitions, allowing for consistent characterization of cases over time. Data in 2017 will include genetic characterization of isolates.