551. Burden of Illness in Carbapenem-Resistant Acinetobacter baumannii Infections in US Hospitals (2014 to 2018)

Background Infections caused by Acinetobacter baumannii present a challenge for treating physicians due to the high level of antimicrobial resistance. The current analysis compared the burden of illness in patients infected with carbapenem-resistant (CR) vs. -susceptible (CS) strains of A. baumannii. Methods Hospitalized adult patients with microbiologically confirmed A. baumannii infections (defined as a positive culture and receipt of antibiotics between 2 days prior to 3 days after the culture) included in the Premier Healthcare Database were retrospectively evaluated. Patient characteristics including demographics, comorbidities, time of infection onset and site of infection were assessed. Comparative outcomes between CR and CS patients assessed included in-hospital mortality, length of hospital stay (LOS), ICU LOS, and discharge status. Outcomes were also stratified by site of infection. Results A total of 3,471 patients admitted between January 1, 2014 and June 30, 2018 were included. Patients with CR strains of A. baumannii were older (62 vs. 59 years), more likely to have Charlson Comorbidity Index ≥3 (63.4% vs. 56.1%), more likely admitted from a healthcare origin (30.3% vs. 11.4%) and less likely to have the onset of infection within first 48 hours of hospitalization (58% vs. 69%) than those with CS strains. CR patients had increased inpatient mortality compared with CS patients (16.3% vs. 11.0%), driven primarily by patients with bloodstream infections (42.6% vs. 12.4%, respectively, P < 0.001). CR patients had a non-significantly increased median overall LOS from the onset of infection (9 vs. 8 days, P = 0.068), were more likely to be admitted to the ICU, and were significantly less likely to be discharged home (16% vs. 47%, P < 0.001). Hospitalization charges were considerably higher for CR patients (table). Readmission rates were high among CR patients and were similar to patients with CS infections. Conclusion Patients with CR strains of A. baumannii face a greater burden of illness compared with CS patients, experiencing increased mortality, ICU admission and LOS, and incur higher hospitalization charges. Furthermore, CR patients were less likely to be discharged home after admission. Disclosures All authors: No reported disclosures.