Study Finds Low Rate of Asymptomatic C Difficile Carriage in Hospitals

A limited population of patients in hospitals were found to be asymptomatic carriers of Clostridioides difficile, according to the results of a study published in Frontiers in Medicine. The study noted that exposure to C. difficile can cause asymptomatic carriage or C. difficile infection (CDI), which has a variety of clinical presentations and outcomes, including mild diarrhea, severe colitis, and death, the study authors noted.

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“Main risk factors for asymptomatic C. difficile carriage included previous antibiotic treatment, use of gastric acid suppression therapy, prior hospitalization and history of CDI,” the study authors wrote. “Risk factors described in the literature vary widely, depending especially on the sampling technique, the C. difficile detection method, the population targeted and the epidemiology situation (outbreak versus endemicity).”

The analysis was based on screenings from 11 health care centers in France. Investigators noted that approximately half of all nosocomial gastrointestinal infections in European hospitals can be traced to C difficile. Further, CDI incidence among hospitalized patients has increased over the past 2 decades, according to the study. CDI is difficult to contain in health care settings because some patients are unknowing carriers of the toxigenic strains of the infection.

“A recent study showed that the environment of asymptomatic C difficile carriers is as contaminated as that of symptomatic CDI patients,” the authors wrote. “A quasi-experimental controlled study revealed that identification and isolation of C difficile carriers was associated with a decreased incidence of CDI.”

Investigators noted that routine screening for asymptomatic carriers is not currently included in recommended infection control guidelines. To address this gap, the authors screened 2389 patients with a median age of 62 years who had been hospitalized for more than 24 hours across 11 hospitals in the Paris area between September 2019 and January 2020.

The findings showed that 185 patients (7.7%) tested positive for CDI, of whom 93 patients were positive for toxigenic strains (3.9% of the total). Most (82.8%) of the patients were found to be asymptomatic, with an overall prevalence of 3.2%. The investigators noted that said these rates were lower than what was previously reported.

“This result may reflect differences in studied populations, or local epidemiology such as hospital outbreaks. It can also be explained by different microbiological techniques used to isolate C difficile,” the study authors wrote. “We used rectal swabbing and direct culture whereas others used stool samples and enriched culture.”

The study also showed a significant difference in groups by age. Children 3 years of age and younger had a C difficile positivity rate of 22.4% and a toxigenic C difficile rate of 7.0%, which were similar rates to findings from previous studies.

Among those older than 3 years of age, prior CDI and co-carriage of multidrug-resistant organisms were linked to an elevated risk of asymptomatic toxigenic carriage of C difficile.

However, patients who consumed raw milk products were less likely to be colonized, which the investigators hypothesized was because milk-associated bacteria produce a barrier effect.

Investigators said the findings cannot necessarily be generalized because only 55.7% of eligible patients were screened and rectal swabbing is less sensitive than stool specimens.

“In conclusion, the prevalence of C. difficile toxigenic carriage was low in patients >3 years old (3.5%), but higher in ≤3 years old (7.0%) and in patients hospitalized >3 days (4.6%). These patients and may therefore represent a potential reservoir for CDIs,” the study authors wrote.

Reference

Jolivet S, et al. Prevalence and risk factors of toxigenic Clostridioides difficile asymptomatic carriage in 11 French hospitals. Frontiers in Medicine. Volume=10. Year=2023. https://www.frontiersin.org/articles/10.3389/fmed.2023.1221363. DOI=10.3389/fmed.2023.1221363. Accessed August 7, 2023.