Background: Recent reports suggest that infections due to fluoroquinolone-resistant Escherichia coli (FREC) are an increasingly common complication of transrectal biopsy of the prostate (TBP) in the United States. A better understanding of the magnitude and scope these infections is needed to guide prevention efforts. Our objectives are to determine if the incidence of infections due to FREC after TBP has increased nationwide in the Veterans Affairs Healthcare System (VAHS) and to identify risk factors for infection.
Methods: Using national VAHS databases, we retrospectively identified patients undergoing TBP between 1/1/2000 and 12/31/2013 and determined the incidence of Urinary Tract Infections (UTI) and bacteremia with E. coli and of FREC within 30 days after TBP. We also determined the proportion of all E. coli urinary and blood isolates that were resistant to fluoroquinolones during the same time period. A nested case-control study of patients undergoing TBP from 2011 through 2013 was conducted to identify risk factors for infection with FREC.
Results: 245,618 patients undergoing 302,168 TBP procedures from 2000 through 2013 were included in the cohort study, and 59,469 patients undergoing TBP from 2011 through 2013 were included in the nested case-control study. Figure 1 shows the incidence of post-TBP UTI due to E. coli, stratified by fluoroquinolone susceptibility, and the concurrent yearly prevalence of fluoroquinolone resistance in all E. coli urinary isolates. Between 2000 and 2013, there was a five-fold increase in the incidence of E. coli UTI (0.18% to 0.93%) and four-fold increase in the incidence of E. coli bacteremia (0.04% to 0.18%) after TBP that was attributable to an increase in the incidence of FREC UTI (0.03% to 0.75%) and bacteremia (0.01% to 0.14%). This occurred in parallel with increasing rates of fluoroquinolone-resistance in all E. coli isolates. By multivariable logistic regression analysis, independent risk factors for FREC UTI after TBP included diabetes mellitus, fluoroquinolone exposure, prior hospitalization, and prior cultures with fluoroquinolone-resistant gram-negative bacilli.
Conclusion: In the VAHS, the incidence of E. coli infection after TBP has increased significantly since 2000 due to a dramatic rise in infections with FREC.
B. Wilson, None
T. Zabarsky, None
C. J. Donskey, None