Reverse Engineering the Prevention of Clostridium difficile

Silvia Munoz-Price, MD, PhD from the Medical College of Wisconsin

Silvia Munoz-Price, MD, PhD

Understanding the risk factors and sources of Clostridium difficile (C. difficile) can assist in preventing or even reversing C. difficile colonization and transmission, according to a new paper.

“This is a review/commentary article that provides a high level overview of the literature dealing with C. difficile colonization and the microbiome changes associated with C. difficile colonization,” author Silvia Munoz-Price, MD, PhD from the Medical College of Wisconsin in Milwaukee told MD Magazine.

In terms of potential for C. difficile colonization, after reviewing the literature, the authors posited that the exposures to and transmissions of C. difficile does occur outside of hospitals. Additionally, it seemed like the majority of patients became symptomatic during their hospital stay, compared to acquiring C. difficile while hospitalized.

For example, the investigators cited one study from Canada in 2006—2007 where more than 4000 patients were screened for C. difficile colonization upon hospitalization, during their stay (on a weekly basis) and at discharge. Four percent of the patients were colonized upon hospitalization and 3% quired C. difficile during their stay in the hospital.

Community-acquired C. difficile appeared to be on the rise. The authors discussed a decade-long Minnesota study where community acquired C. difficile infection rates rose from 2.8 to 14.9 per 100,000 person years within the 10-year span. The patients in that study more likely to acquire C. difficile were younger, female, and healthier than patients with hospitalization acquired C. difficile. The reviewers also said that rates of community acquired C. difficile have also been rising in Finland, Australia and England, according to published studies.

Most of the common risk factors for community acquired C. difficile infections still applied, the researchers found, including antibiotic exposure, household contact and animals. A 2013 study showed that two-thirds of community acquired C. difficile patients were exposed to antibiotics in the preceding 12 weeks of their infection, and about a third had been exposed to proton pump inhibitors.

While studies examining transmissibility within households are difficult to come by, the study authors found one from Quebec. In a review of 2222 cases of C. difficile diagnosed between 1998 and 2009, 8 cases were designated to be transmitted by household contacts. However, the researchers noted, confirmation using strain typing was not performed in that study.

Looking at farm livestock, a 2013 Dutch study showed that people with daily contact with pigs showed rates of C. difficile positivity of 25% and 14% in those with weekly contact. In the same study, C. difficile was found in the manure from all the farms in 10% to 80% of the samples per farm. The reviewers also said that C. difficile has been found in the stool of farm chickens, calves and retail ground meat. Dogs and cats are also known to culture positive for C. difficile, and the researchers wrote that the bacteria can also be present in vegetables and water (tap water, swimming pools, and rivers, lakes and seas). They hypothesized that the presence of C. difficile in vegetables may come from the use of organic fertilizer.

“We envision that in the future we should be able to take advantage of our increasing knowledge about microbiome changes so that we will be able to: identify patients at risk for de novo C. difficile colonization during their hospitalization, and manipulate our patients' microbiome to prevent or reverse C. difficile colonization,” Munoz-Price continued. “Different from what we do now, the latter would be accomplished not by withholding or changing antibiotics but by correcting the deficient flora of a patient in an individualized fashion. This new approach would revolutionize the field of Infection Control and Antibiotic Stewardship.”

The paper, titled “Clostridium difficile Exposures, Colonization, and the Microbiome: Implications for Prevention,” was published in the journal Infection Control & Hospital Epidemiology.