Study: use of high-risk antibiotics leads to increase in C. difficile infections

By Jay Kumar, PSQH 

The increased prevalence of hospital-associated C. difficile infections is thought to be tied to higher hospital-wide use of four classes of antibiotics, according to a new study published this week in Infection Control & Hospital Epidemiology. ICHE is the journal of the Society for Healthcare Epidemiology of America.

For every 100 days of facility-wide antibiotic therapy using one of these high-risk antibiotics, researchers found a 12% increase in hospital-associated C. diff infection. However, further analysis found that only cephalosporins were significantly correlated with hospital-associated C. diff, which can cause life-threatening symptoms including diarrhea and inflammation of the colon, affecting nearly 500,000 patients in the U.S. annually and causing approximately 15,000 deaths per year.

The researchers attributed the lack of significant results for C. diff with some classes of antibiotics to reduced use through stewardship.

“This highlights the importance of ongoing monitoring of antibiotic use in hospitals for patient safety as it relates to the effect of antibiotics on C. difficile infections. In the future, it will also be important to look at the effect of antibiotic use on both C. difficile infection and antibiotic resistance simultaneously, rather than examining each piece as separate endeavors,” said L. Clifford McDonald, MD, medical epidemiologist at the Centers for Disease Control and Prevention and an author on the study, in a release.

“This is possible in our era of electronic medical records because antibiotic usage data has become more available,” McDonald added. “A facility can use the National Healthcare Safety Network Antibiotic Use and Resistance Module and interpret results using the standardized antibiotic administration ratio to have a better understanding of how antibiotics are being used and identify areas for improvement.”

The four classes of antibiotics included in this study have been identified in recent guidelines as high risk, but results of previous research evaluating facility-level use of the antibiotics and rates of C. diff have been inconsistent. This study looked at microbiological and pharmacy data from 171 hospitals included in the BD Insights Research Database to examine the impact of hospital-wide use of these four classes of antibiotics on C. diff.

The four classes of medications were cephalosporins (used for a variety of bacterial infections), fluoroquinolones (used for respiratory and urinary tract infections), carbapenems (broad spectrum antibiotics used for unresponsive infections), and lincosamides (used for staph and strep infections).

The study also found that higher C. diff rates were associated with a larger portion of patients over age 65, higher rates of community-onset C. diff, longer length of stay, and teaching hospitals.