501. Risk of Infection in Persons Colonized with Carbapenemase-Producing Enterobacteriales (CPE) in Ontario, Canada

BACKGROUND: We aimed to assess the risk of subsequent infection among patients colonized by CPE. METHODS: The Toronto Invasive Bacterial Diseases Network (TIBDN) has conducted population-based surveillance for CPE colonization/infection in Toronto and Peel region, Ontario, Canada, since CPE were first identified (2007). All laboratories report all CPE isolates to TIBDN. Clinical data are collected via patient interview and hospital chart review. Initially colonized patients are followed for 5y; subsequent CPE infection is defined as an episode with onset >3 days after initial detection of CPE colonization that meets National Healthcare Safety Network criteria for infection with a clinical isolate of CPE. RESULTS: From 2007 to 2018, 790 persons with CPE colonization/infection were identified. Among 364 cases colonized at identification, 42 (12%) subsequently had at least one clinical isolate, and 23 (6%) had an infection: 8 with bacteremia (primary or secondary), 7 UTI, 5 pneumonia, and 3 other. The median time from identification of colonization to infection was 21 days (IQR 7–38), with a probability of developing an infection of 7% at 3 months, and 18% by 3 years (figure). In 305 cases with data available to date, older persons, those admitted to the ICU, and those with current/recent invasive medical devices were more likely to develop infection (table). Gender, underlying conditions and other procedures were not associated with risk of infection. There was a trend to infections being more likely in patients colonized with K. pneumoniae (52% vs. 35%, P = 0.13). CONCLUSION: The risk of subsequent infection in our cohort was 18%, with highest risk in the first 3 months; most infections occurred in patients requiring intensive care unit admission and invasive medical devices. [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.