
Background: Antibiotic exposure in the intestinal tract is the most important risk factor for Clostridium difficile infection (CDI). Oral administration of beta-lactamase enzymes has been shown to be effective in eliminating the portion of intravenous beta-lactam antibiotics that is excreted into the intestinal tract, thereby preserving the microbiota during therapy. Development of such enzymes requires understanding the patterns of use of beta-lactams and the frequency of healthcare facility-associated (HCFA)-CDI associated with them given alone or in combination with other classes of antibiotics.
Methods: Using nationwide databases, we determined the frequency of prescription of systemic antibiotics for all acute care hospitalizations in the VHA from 2012-2014. The rate of HCFA-CDI (cases per hospitalization) was calculated for any antibiotic treatment and by selected beta-lactam and fluoroquinolone (FLQ) agents.
Results: Of 1,077,559 hospitalizations among >760,000 patients, 544,541 (51%) included treatment with 1 or more systemic antibiotics, including 423,552 (39%) treated with 1 or more of the beta-lactam or FLQ agents studied (Table). HCFA-CDI occurred in 1.2% of all hospitalizations that included treatment with systemic antibiotics versus 0.14% of hospitalizations that did not include antibiotic therapy (P<0.001). The rate of HCFA-CDI was higher when stays included multiple antibiotics, both FLQ and beta-lactams, and ceftriaxone or cefepime versus cefazolin (Table and Figure).
Conclusion: The beta-lactam agents studied were
prescribed in nearly a quarter of analyzed hospitalizations and were frequently
associated with HCFA-CDI. Interventions that prevent disruption of the
intestinal microbiota associated with these agents could have a significant
impact on rates of HCFA-CDI.
Table. Antibiotic prescriptions and HCFA-CDI in the Veterans Affairs Healthcare System from 2012 through 2014
Figure. Frequency of HCFA-CDI associated with different antibiotic exposures, stratified by hospital versus community onset

B. Wilson,
None
E. Saade, None
C. J. Donskey, None