506. Urinary Catheters Are Associated with Progression from Bacteriuria to Invasive Infections in Patients with Carbapenem-Resistant Enterobacteriaceae, Metropolitan Atlanta, 2011–2017

BACKGROUND: Patients with carbapenem-resistant Enterobacteriaceae (CRE) bacteriuria have better outcomes than patients with an invasive CRE infection, but patients with bacteriuria may subsequently develop an invasive infection (“progression”). We sought to evaluate risk factors, particularly urinary catheters, for progression from CRE bacteriuria to an invasive CRE infection within one year. METHODS: We used population-based active surveillance data from the Georgia Emerging Infections Program to identify patients in metropolitan Atlanta with CRE in urine, but not in a concomitant or previous sterile site between August 1, 2011 and July 31, 2017. CRE was defined as an isolate resistant to tested third-generation cephalosporins and a minimum inhibitory concentration of ≥4 µg/mL for meropenem, doripenem or imipenem. We then assessed if these patients developed an invasive CRE infection (positive sterile site culture) with the same organism between one day and one year later. Demographics, culture site, comorbidities, and risk factors were obtained by chart review. Univariable analyses and multivariable logistic regression with progression as the outcome were performed in SAS 9.4. RESULTS: We identified 551 patients with CRE bacteriuria in 6 years, with an annual incidence of 1.1 cases/100,000 population. Many patients previously resided in long-term care facilities (48%), had a Charlson comorbidity index (CCI) >3 (38%), a central venous catheter (CVC, 34%) or a decubitus ulcer (27%, Table 1). Twenty-five patients (5%) progressed from CRE bacteriuria to an invasive CRE infection within one year (median 34 days). Predictors of progression in univariable analyses included the presence of a urinary catheter (OR 6.4 [95% CI: 1.9–21.6]), decubitus ulcer, CVC or other indwelling device, Klebsiella pneumoniae, black race, CCI >3, and ICU stay after urine culture was obtained (Table 2). In a multivariable analysis, urinary catheter (OR 4.6 [95% CI: 1.3–16.1]) predicted progression as well as K. pneumoniae, CCI >3 and CVC. CONCLUSION: Progression from CRE bacteriuria to an invasive CRE infection is rare but clinically significant and is associated with urinary catheters. Future interventions should target urinary catheter removal, where possible, in patients with CRE bacteriuria. [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.