Carbapenem-resistant Enterobacteriaceae (CRE) is a reportable condition in Tennessee. Cases are captured in the NEDSS Base System (NBS), the electronic reportable disease surveillance system. The 2015 state reporting guidelines required all cases of CRE to be reported to public health, and for all isolates to be submitted to the state public health laboratory (SPHL) for further characterization.
METHODS:
TDH initiated an evaluation of the current surveillance system for CRE to identify lapses in reporting and the submission of isolates to the SPHL. Data sources included NBS and SPHL line lists of laboratory results for the first two quarters of 2015. For this analysis, each patient was counted only once as a case of CRE for the time period.
RESULTS:
A total of 266 individual patients were reported to NBS as cases of CRE, and isolates for 89 of these cases, or 33%, were submitted to the state public health laboratory (SPHL) for carbapenemase and resistance mechanism testing. The SPHL received isolates for 430 individual patients for CRE testing. Only 85 of the 353 isolates from Tennessee residents, or 24%, were reported as cases to NBS.
CONCLUSIONS:
This preliminary analysis suggests many more isolates were submitted to the SPHL for further characterization than were reported to public health as cases. One possible explanation may be related to the implementation of contrasting Emerging Infections Program (EIP) and reportable disease case definitions for CRE. To ensure capture of all isolates meeting either definition, all nonsusceptible isolates across the state were required for submission to the SPHL. Consequently, the 353 isolates submitted from Tennessee residents may not have met the reportable disease case definition, which required submission only of resistant isolates. Additionally, when healthcare facilities or laboratories submit an isolate to the SPHL, the documentation does not always identify the organism or provide antimicrobial susceptibility results. Therefore, some of the isolates may have been for nonreportable organisms or isolates that were only intermediate to carbapenems. Given concerns about lapses in reporting and the submission of isolates, TDH and the SPHL collaborated to implement improved communication procedures beginning in the fall of 2015. We expect these interventions to increase the proportion of the total isolates submitted to SPHL that are subsequently reported to NBS. A more comprehensive analysis will be completed when the 2015 data are finalized to evaluate the impact of these interventions.