Infections caused by Gram-negative pathogens resistant to carbapenems have limited treatment options and are associated with increased morbidity and mortality. We evaluated the rates, infection sources, and pathogen types associated with carbapenem non-susceptible (Carb-NS) Gram-negative isolates in intensive care unit (ICU) and non-ICU settings in a large US hospital database.
We conducted a retrospective cross-sectional analysis of carbapenem susceptibility of all non-duplicate isolates of Gram-negative pathogens collected from January 1, 2017 to December 31, 2017 at 358 US hospitals in the BD Insights Research Database. Carb-NS isolates included all pathogens reported at the institutional level as intermediate or resistant.
Of 312,075 non-duplicate Gram-negative isolates, 10,698 (3.4%) were Carb-NS. Respiratory samples were the most frequent source of Carb-NS isolates (35.2%); skin/wound accounted for 23.6%. Pseudomonas aeruginosa was the most common Carb-NS pathogen (58.5% of isolates) and about 30% were Enterobacteriaceae. The highest rates of Carb-NS were found in Acinetobacter spp. (35.6%) and P. aeruginosa (14.6%). The rate of Carb-NS was significantly higher in ICU (5.4%) versus non-ICU settings (2.7%; P< 0.0001 in univariate analysis). This difference remained significant in multivariable analysis after adjusting for infection and hospital characteristics (odds ratio=1.35; 95% confidence interval 1.17–1.56; P < 0.0001).
Infections caused by Carb-NS isolates pose a significant clinical problem across different sources of infection, species of pathogen, and hospital setting. Widespread infection prevention and antimicrobial stewardship initiatives, in combination with new treatment options, may be required to reduce the burden of carbapenem resistance in healthcare settings.