SAN DIEGO, CA—Even though probiotics are frequently administered in pediatric intensive care units (ICUs), incidence of probiotic-associated bacteremia appears to be low, authors of a single-institution case-control study reported at IDWeek 2015.

“Despite a large number of administered doses in the ICU, Lactobacillus bacteremia was a rare event,” Kelly B. Flett, MD MMSc, of the Division of Infectious Diseases, Boston Children’s Hospital in Boston, Massachusetts. “Case patients were more likely to be male, but otherwise we did not identify additional risk factors for Lactobacillus bacteremia.”

Dr. Flett called for multi-center studies that can provider larger sample sizes and identify additional risk factors. ICUs increasingly administer probiotics like Lactobacillus rhamnosus GG but little is known about Lactobacillus bacteremia risks among ICU patients who receive these probiotics, Dr. Flett explained.

To find out, Dr. Flett and colleagues performed a case-control study on 644 pediatric ICU patients who had received 15,736 doses of Lactobacillus GG from January 2009 through June 2014. A total of 18 ICU patients had developed Lactobacillus bacteremia, of whom six patients had received probiotics. Each of these cases was matched to up to 3 randomly selected controls who did not have bacteremia but had received Lactobacillus within 90 days of the date of bacteremia in the matched case, and “who had an equal or higher number of ICU days prior to censorship,” Dr. Flett explained. “Cases were censored at day of bacteremia and controls at day of ICU discharge. Potential risk factors were assessed during the 7-day period prior to censorship and summarized using descriptive statistics and 95% confidence intervals.”

No patients in either group had cancer diagnoses or a history of transplantation, Dr. Flett reported. Only 17% of cases had cardiovascular disorders compared with 56% of controls. All six cases were diagnosed in males.

During the 7 days prior to bacteremia, the cases had received 15.2 days of therapy (95% CI: 2.8, 27.6), compared with 8.2 days of therapy (95% CI: 6.0, 10.3) for the controls.

A total of 83% of cases and 81% of controls had a central venous catheter; median number of days in ICU was 56.8 and 66.7, respectively. A numerically higher proportion of cases vs. controls had a urinary catheter (33% vs. 6%), ventilator dependence (50% vs. 25%), and gastrostomy tube (83% vs. 69%), but these differences did not reach statistical significance.