488. Epidemiology and Outcomes for Stenotrophomonas maltophilia Infections at a Tertiary Care Center in Detroit, MI

Abstract

Background Stenotrophomonas maltophilia is a gram-negative, biofilm-forming bacterium. The increasing use of antibiotics has allowed this bacterium to become a predominant nosocomial pathogen with inherent resistance to several antibiotics. In this study, we describe the epidemiology and outcomes for patients treated for S. maltophilia infections who were admitted to Detroit Medical Center from January 1, 2010 to August 31, 2018.MethodsThis was a retrospective cohort study that included S. maltophilia cultures isolated from sterile body sites from January 1, 2010 to August 31, 2018. Nonsterile body sites and tissue cultures were excluded, as well as cultures that were deemed to be colonization based upon clinical evaluation. Appropriate empiric antibiotic therapy was defined as a regimen administered three days prior to or four days following the S. maltophilia culture date. Appropriate definitive therapy was defined as antibiotic treatment administered five to fourteen days following the culture date. Patient data were extracted from the electronic medical record which included demographic information, length of stay and outcome data. Bivariate analysis was performed using SAS database.Results126 patients with S. maltophilia infections were analyzed: 89 had bacteremia, 22 had lung infections, and 15 had other infections. The median length of stay was 16 days (IQR 6–30 days). Sixty-one patients (48%) admitted to the ICU had a median length of stay of 10 days (Table 2). Among the patients that were followed after discharge, 21 were readmitted within 30 days. Table 1 highlights the bivariate analysis of patients who died within 30 days vs. survived. Patients who received definitive antibiotic therapy had lower 30-day mortality (Table 1; CI 95%, OR=0.37, P = 0.03). In addition, patients who were bacteremic had a lower 30-day mortality (Table 1; CI 95%, OR=0.40, P = 0.04). There was no significant difference in mortality among patients who received appropriate empiric antibiotic therapy (P = 0.67).ConclusionThis study demonstrates that nonbacteremic patients infected with Stenotrophomonas have higher 30-day mortality than those with bacteremia. This necessitates that diseases associated with this bacterium should be taken seriously and treated with definitive appropriate antibiotics. Disclosures All authors: No reported disclosures.