Increasing risk of infectious complications after transrectal ultrasound-guided prostate biopsies: time to reassess antimicrobial prophylaxis?

Abstract

Background: An increasing risk of infectious complications following transrectal ultrasound-guided prostate needle biopsy (PNB) has been observed recently in some centers.

Objective: To delineate the risk factors associated with post-PNB bacteremia and/or urinary tract infection (UTI) and determine why this risk has risen over time.

Design, setting, and participants: A case-control study in a Canadian tertiary-care center. Cases were all patients who developed bacteremia and/or UTIs after PNB between 2002 and 2011; controls were randomly selected among patients who underwent a PNB without such complications.

Outcome measurements and statistical analysis: Crude and adjusted odds ratios and their 95% confidence intervals were calculated using logistic regression.

Results and limitations: A total of 5798 PNBs were performed during the study period, following which there were 48 cases of urinary sepsis (42% with bacteremia). The incidence increased from 0.52 infections per 100 biopsies in 2002-2009 to 2.15 infections per 100 biopsies in 2010-2011 (p<0.001). Escherichia coli was the predominant pathogen (75% of cases). Among 42 patients whose post-PNB infection was caused by aerobic or facultative Gram-negative rods, 22 patients (52%) were infected by pathogens resistant to ciprofloxacin. Independent risk factors for post-PNB infection were diabetes, hospitalization during the preceding month, chronic obstructive pulmonary disease, and performance of the biopsy in 2010-2011. In 2010-2011, the minimal inhibitory concentrations for ciprofloxacin increased compared with 2002-2009 (p<0.03). The major limitation of the study was its retrospective hospital-based nature, which hampered data collection on outpatient antibiotic prescriptions.

Conclusions: In the past 2 yr, ciprofloxacin resistance contributed to the increasing incidence of post-PNB infections in our center. Novel antibacterial prophylaxis approaches need to be evaluated.