Antimicrobial use and risk for recurrent clostridium difficile infection

Background: Although antimicrobial use during and immediately after Clostridium difficile infection (CDI) is discouraged, the frequency and consequences of such use are poorly defined. We sought to determine the frequency of non-CDI antimicrobial therapy during and after treatment for CDI, and the association of such therapy with recurrent disease. Methods: Retrospective review of all CDI cases at a Veterans Affairs medical center from 2004-2006. Outcomes were non-CDI antimicrobial use during and within 30 days after completing CDI treatment, and recurrent CDI. Results: From 2004 to 2006, new-onset CDI occurred in 249 unique patients. No follow-up information was available for 3 patients, leaving 246 as study subjects. Of these, 141 (57%) received non-CDI antimicrobials, including 61 (25%) who received non-CDI antimicrobials during CDI treatment, and 80 (33%) who received non-CDI antimicrobial therapy after CDI treatment. With adjustment for age, disease severity, duration of CDI treatment, and recent hospital or intensive-care unit stay, receipt of non-CDI antimicrobials after CDI treatment was significantly associated with recurrent CDI (odds ratio [OR] 3.02; 95% confidence interval [CI], 1.66-5.52), compared with no antimicrobial use. Antimicrobial use during CDI treatment was not associated with recurrent CDI (OR 0.79; 95% CI, 0.40-1.52). Neither number of antimicrobial courses nor antimicrobial days was associated with recurrence. Conclusions: Non-CDI antimicrobial therapy after an episode of CDI is common and is associated with a 3-fold increase in the odds of recurrent disease. The added risk associated with antimicrobial exposure (regardless of duration) should be considered if such therapy is contemplated.