Risk Factors for the Acquisition of <i>Enterococcus faecium</i> Infection and Mortality in Patients with Enterococcal Bacteremia: A 5-Year Retrospective Analysis in a Tertiary Care University Hospital

• Main Authors: Atsushi Uda, Katsumi Shigemura, Koichi Kitagawa, Kayo Osawa, Kenichiro Onuma, Yonmin Yan, Tatsuya Nishioka, Masato Fujisawa, Ikuko Yano, Takayuki Miyara
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Antibiotics
• Subjects: enterococcal; bacteremia; epidemiology; risk factors; mortality; antimicrobial stewardship
• Online Access: https://www.mdpi.com/2079-6382/10/1/64

The incidence of bacteremia caused by <i>Enterococcus faecium</i>, which is highly resistant to multiple antibiotics, is increasing in Japan. However, risk factors for the acquisition of <i>E. faecium</i> infection and mortality due to enterococcal bacteremia are not well known. We compared demographic, microbiological, and clinical characteristics using a Cox regression model and univariate analysis. We performed a multivariate analysis to identify risk factors for patients treated between 2014 and 2018. Among 186 patients with enterococcal bacteremia, two groups included in the Kaplan–Meier analysis (<i>E. faecalis</i> (n = 88) and <i>E. faecium</i> (n = 94)) showed poor overall survival in the <i>E. faecium</i> group (HR: 1.92; 95% confidence interval: 1.01–3.66; <i>p</i> = 0.048). The median daily antibiotic cost per patient in the <i>E. faecium</i> group was significantly higher than that in the <i>E. faecalis</i> group ($23 ($13–$34) vs. $34 ($22–$58), <i>p</i> < 0.001). <i>E. faecium</i> strains were more frequently identified with previous use of antipseudomonal penicillins (OR = 4.04, <i>p</i> < 0.001) and carbapenems (OR = 3.33, <i>p</i> = 0.003). Bacteremia from an unknown source (OR = 2.79, <i>p</i> = 0.025) and acute kidney injury (OR = 4.51, <i>p</i> = 0.004) were associated with higher risks of 30-day mortality in patients with enterococcal bacteremia. Therefore, clinicians should provide improved medical management, with support from specialized teams such as those assisting antimicrobial stewardship programs.