Program to rapidly identify and contain cases of CRE is achieving improvements, CDC finds

Rates of carbapenem-resistant Enterobacteriaceae (CRE) declined from 2006 to 2015, but testing in 2017 did identify 221 isolates expressing carbapenemases other than Klebsiella pneumoniae.

Recent efforts to speed containment of cases of multidrug-resistant bacteria appear to have successfully slowed their spread, according to a new CDC study.

Researchers used 2006 to 2015 data from the National Healthcare Safety Network to calculate annual change in pathogens not susceptible to extended-spectrum cephalosporins (ESBL phenotype) and carbapenem-resistant Enterobacteriaceae (CRE). Testing results for CRE and carbapenem-resistant Pseudomonas aeruginosa (CRPA) were also analyzed. Results were published in Morbidity and Mortality Weekly Report on April 3.

Both types of drug resistance decreased over the studied time period, but the percentage of ESBL phenotype Enterobacteriaceae decreased by only 2% per year, while CRE decreased by 15% per year. From January to September 2017, carbapenemase testing was performed for 4,442 CRE isolates (32% positive) and 1,334 CRPA isolates (1.9% positive), leading to 1,489 screening tests to identify asymptomatic carriers (11% positive). Of the carbapenemase-producing isolates, 15.5% expressed carbapenemases other than Klebsiella pneumoniae carbapenemase (KPC).

The greater decrease in CRE than ESBL “might be attributable, at least in part, to more directed response employed to slow the spread of CRE once it was identified,” the study authors said. They noted that testing volume and public health response increased over the first three quarters of 2017. The findings regarding the non-KPC carbapenemases highlight potential future drug-resistance threats and the necessity of preventing the spread of these bacteria, they said.

The authors called on health care facilities to recognize “the importance of an aggressive, early, and coordinated response” to cases of multidrug-resistant bacteria. They noted that research is underway on additional strategies for preventing the spread of multidrug-resistant bacteria, including patient decolonization, microbiome manipulation, and methods to decrease the time from specimen collection to public health response.