SAN DIEGO, CA—Administering a three-Lactobacillus spp. probiotic to patients undergoing antibiotic therapy might reduce the frequency of nosocomial Clostridium difficile infections (CDI), suggest findings from a single-institution study reported at IDWeek 2015.

“Probiotic administration targeted to antibiotic recipients was associated with a trend toward a reduced CDI incidence,” reported lead study author William Trick, MD, Cook County Health & Hospitals System, Chicago, Illinois, and coauthors. “The decline was evident six months post-implementation, possibly reflecting delayed impact due to combination of antibiotic and environmental risk factors.”

During the final six months of the intervention, CDI rates among patients who received probiotic were significantly lower than patients who were administered antibiotics without probiotic (risk ratio [RR] 0.6; 95% CI: 0.4–0.9; P=0.01).

Previously, research and meta-analyses indicated that probiotics can help to reduce nosocomial CDIs as a primary prevention measure. The coauthors evaluated CDI rates at a large teaching hospital before and after administering a probiotic preparation containing three Lactobacillus species (L. casei, L. acidophilus, and L. rhamnosus) to adult antibiotic recipients. The preparation has been evaluated in three prior randomized controlled trials, Dr. Trick noted.

The study excluded patients in the oncology unit, those administered preoperative antibiotics, those with pancreatitis, leukopenia, and post-transplant patients.

“We evaluated 12-month baseline (October 1, 2012 to September 30, 2013) and intervention (Nov ember 1, 2013 to October 31, 2014) periods,” Dr. Trick said. “October 2013 was a 1-month run-in. Our protocol was to administer probiotic <12 hours after initial antibiotic receipt, to continue daily for five days post final dose.”

Before the study began, the hospital had adopted PCR testing, antibiotic controls, enhanced cleaning, and hand hygiene campaigns, Dr. Trick noted. But no new such interventions were initiated during the study.

The authors noted several study limitations. Only 67% of patients who developed CDIs had been eligible for probiotic administration, and 28% of patients assigned to the probiotic study arm, missed doses or started their probiotic intervention late, Dr. Trick noted.

“A large percentage of cases were ineligible for probiotic receipt or received the doses late or missed doses, potentially minimizing the impact on ecologic rates,” Dr. Trick cautioned. There was also incomplete data on community-onset CDIs, and importantly, comparisons of the study arms’ outcomes may have been affected by differences in each arm’s patient population, he acknowledged.