Burden of Carbapenem-Resistant Gram-Negative Infections in US Hospitals

Abstract

Carbapenem-resistant (CR) Gram-negative infections have received much attention because of the lack of effective treatment. This study explored the burden of CR Gram-negative pathogens on hospital stay and intensive care unit (ICU) stay. Hospitalized patients with laboratory-confirmed infections due to Gram-negative pathogens from specified infection sites between 2010 and 2015 were identified from Premier Healthcare Database. Two cohorts were defined using local hospital carbapenem susceptibility test results [CR cohort and carbapenem susceptible (CS) cohort]. However all patients with S. maltophilia were considered CR because of its inherited resistance to carbapenem. The length of total hospital stay and length of ICU stay were compared between two cohorts by pathogen and infection site (blood, respiratory, urinary, and other). From October 2010 to September 2015, 23,426 of 260,280 (9%) patients infected with non-fermenters (A. baumannii, P. Aeruginosa, and S. maltophilia), K. pneumoniae or E. coli had carbapenem-resistant pathogens. About 89% of CR infections had one of the three non-fermenters. The median number of days of hospitalization by pathogen and infection site is shown in the table below. Length of total hospital stay was longer in CR cohort than CS cohort in each instance, except for A. baumannii in respiratory. Compared with patients with CS pathogens, those with CR pathogens were more likely to stay at ICU and had longer days in ICU for each of first four pathogens shown in above table at each infection site, except for patients with A. baumannii respiratory infection where the median ICU stay for CS patients was 4 days longer than CR patients. Patients with S. maltophilia, especially in respiratory, had similar hospital stay and ICU stay to other CR cases. Compared with patients with CS pathogens, those with CR pathogens were more likely to stay at ICU and had longer days in ICU for each of first four pathogens shown in above table at each infection site, except for patients with A. baumannii respiratory infection where the median ICU stay for CS patients was 4 days longer than CR patients. Patients with S. maltophilia, especially in respiratory, had similar hospital stay and ICU stay to other CR cases. In general, patients infected with CR Gram-negative pathogens had longer total hospital stay and ICU stay with the exception of A. baumannii infection in respiratory. These results indicate a heavier disease burden of CR Gram-negative infections, especially from the non-fermenters. B. Cai, Shionogi Inc.: Employee, Salary. R. Echols, Shionogi Inc.: Consultant, Consulting fee. G. Morgan, Shionogi Inc.: Employee, Salary. D. Van Veenhuyzen, Shionogi Inc.: Employee, Salary. M. Ariyasu, Shionogi: Employee, Salary. T. Sawada, Shinogi: Employee, Salary T. D. Nagata, Shionogi: Employee, Salary.