The Utility of Repeat Blood Cultures for Bacteremic Urinary Tract Infections and Associated Durations of Therapy

BACKGROUND: Urinary tract infections (UTIs) are common among hospitalized patients with 10–40% of cases complicated by bacteremia. Recent literature suggests limited utility in repeating blood cultures for non-Staphylococcus aureus bacteremia; however, clinicians often repeat blood cultures to document clearance prior to selecting definitive therapy for bacteremias. Additionally, comparative data evaluating treatment duration for bacteremic UTIs are lacking and clinical practice guidelines do not address optimal duration for bacteremic UTIs. We aimed to evaluate local practice patterns and utility of repeat blood cultures and their influence on treatment durations for bacteremic UTIs. METHODS: We identified patients with bacteremia from a urinary source at the Salt Lake City Veterans Affairs (VA) hospital from a previously compiled cohort of inpatients with bacteremia from any source between November 2013 and October 2015. Demographic and clinical information including presence of comorbidities, source of infection, number of repeat blood cultures collected, repeat blood culture positivity, planned duration of antibiotic therapy and recurrent bacteremia with the same organism within 30 days of discharge were collected by manual chart review. RESULTS: Fifty-three bacteremic UTIs were included during the study period. Ninety-four percent of patients were male with a median age of 77. Repeat blood cultures were drawn in 77% (41/53) of cases; however, only 7% (3/41) of repeats were positive, all with Enterococcus faecalis. Median duration of therapy was 14 days (IQR 14, 15), with a longer mean duration in patients with repeat blood cultures as compared with not (15 vs.. 12 days, P = 0.03). Two patients had recurrent bacteremia with the same organism within 30 days; both with negative repeat blood cultures at the time of initial bacteremia and undetected metastatic complications. CONCLUSION: Patients with bacteremic UTIs are at low risk of persistent bacteremia. Repeat blood cultures are of low utility, specifically with Gram-negative organisms, and may lead to prolonged durations of therapy. The impact of reducing repeat blood culture collection on outcomes, length of stay, and antibiotic durations warrants further evaluation. DISCLOSURES: All authors: No reported disclosures.