To describe national trends in testing and detection of carbapenemasesproduced by carbapenem-resistant Enterobacterales (CRE) and associatetesting with culture and facility characteristics.

Retrospective cohort study.

Department of Veterans’ Affairs medical centers (VAMCs).

Patients seen at VAMCs between 2013 and 2018 with cultures positive for CRE,defined by national VA guidelines.

Microbiology and clinical data were extracted from national VA data sets.Carbapenemase testing was summarized using descriptive statistics.Characteristics associated with carbapenemase testing were assessed withbivariate analyses.

Of 5,778 standard cultures that grew CRE, 1,905 (33.0%) had evidence ofmolecular or phenotypic carbapenemase testing and 1,603 (84.1%) of these hadcarbapenemases detected. Among these cultures confirmed ascarbapenemase-producing CRE, 1,053 (65.7%) had molecular testing for≥1 gene. Almost all testing included KPC (n = 1,047, 99.4%), with KPCdetected in 914 of 1,047 (87.3%) cultures. Testing and detection of otherenzymes was less frequent. Carbapenemase testing increased over the studyperiod from 23.5% of CRE cultures in 2013 to 58.9% in 2018. The South USCensus region (38.6%) and the Northeast (37.2%) region had the highestproportion of CRE cultures with carbapenemase testing. High complexity (vslow) and urban (vs rural) facilities were significantly associated withcarbapenemase testing (P < .0001).

Between 2013 and 2018, carbapenemase testing and detection increased in theVA, largely reflecting increased testing and detection of KPC. Surveillanceof other carbapenemases is important due to global spread and increasingantibiotic resistance. Efforts supporting the expansion of carbapenemasetesting to low-complexity, rural healthcare facilities and standardizationof reporting of carbapenemase testing are needed.