National prevalence estimates for resistant Enterobacteriaceae and Acinetobacter species in hospitalized patients in the United States

Objectives: To determine antimicrobial nonsusceptibility rates for Enterobacteriaceae and Acinetobacter spp. in US hospitals. Methods: We analyzed antimicrobial susceptibilities of non-duplicate Enterobacteriaceae and Acinetobacter spp. isolates reported in 2017 from 375 US hospitals in the BD Insights Research Database. Logistic and Poisson regression modeling methods were used to estimate proportions of resistant isolates and rates per 1000 hospital admissions. National projections were generated based on raking (weighting) methods. Results: The nationwide proportions of resistant isolates in inpatients were an estimated 12.6%, 6.6%, and 1.2% for Enterobacteriaceae with extended-spectrum beta-lactamase (ESBL), multidrug resistant (MDR), and carbapenem-nonsusceptible (Carb-NS) phenotypes, respectively, and 42.4% and 34.5% for Acinetobacter spp. with MDR and Carb-NS phenotypes. Resistance varied by geographic region and hospital size/type. Estimated nationwide rates per 1000 hospital admissions ranged from a high of 7.1 for ESBL Enterobacteriaceae to a low of 0.3 for Carb-NS Acinetobacter spp. The estimated number of isolates occurring in US inpatients each year was 290,220 ESBL, 173,984 MDR, and 30,194 Carb-NS for Enterobacteriaceae and 12,274 MDR and 9,991 Carb-NS for Acinetobacter spp. Conclusions: National prevalence estimates suggest high levels of antimicrobial resistance and a substantial number of patients with resistant Enterobacteriaceae and Acinetobacter spp. in US hospitals. (C) 2019 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.