2410. Clinical Outcomes Associated With Various Treatment Options for Infections Caused by Carbapenem-Resistant Enterobacteriaceae

Abstract

BackgroundInfections caused by carbapenem-resistant Enterobacteriaceae (CRE) have been designated an urgent level threat to public health. With the advent of novel β lactam/β-lactamase inhibitor combinations, the armamentarium against CRE is expanding. Our study aims to evaluate clinical outcomes in patients with CRE infections.MethodsA retrospective study was conducted to compare clinical outcomes in adult patients with documented CRE infections between January 2009 and December 2017 and received either ceftazidime–avibactam (CAZ-AVI) or best available therapy (BAT). Best available therapy was defined as antimicrobials with susceptibility to the causative pathogen according to CLSI breakpoints. The following clinical outcomes were assessed: clinical cure, total length of stay (LOS), 30-day mortality, and infection-related mortality.ResultsOne hundred and fifty patients met criteria for inclusion; 25 in the CAZ-AVI group and 125 in the BAT group. The median Charlson Comorbidity Index (CCI) was 6 in both cohorts, indicating a low baseline probability for survival. The most common primary sites of infection for the CAZ-AVI and BAT cohorts, respectively, were the following: blood (24% vs. 18%, P = 0.580), urine (36% vs. 23%, P = 0.209), intraabdominal (16% vs. 14%, P = 0.754), and lung (12% vs. 27%, P = 0.132). Combination therapy was utilized in 8% of patients in the CAZ-AVI group compared with 42% in the BAT group. Combinations in the BAT group consisted of colistin-based (68%), tigecycline-based (13%), and aminoglycoside-based (13%) regimens. Although clinical cure rates were similar between both groups (80% vs. 72%, P = 0.469), there was a statistically significant difference in both all-cause mortality (24% vs. 73%, P = 0.006) and infection related mortality (4% vs. 26%, P = 0.017) in the CAZ-AVI and BAT groups, respectively. There was a trend toward a lower overall length of stay favoring the CAZ-AVI cohort as opposed to the BAT cohort (16 days vs. 30 days, P = 0.082).ConclusionCAZ-AVI therapy was associated with lower mortality rates for CRE infections and have a high attributable mortality, especially with concomitant bacteremia. Future studies are warranted to confirm these results.Disclosures All authors: No reported disclosures.