Persistent Carriage of Asymptomatic C difficile Common in Health Care Settings

Transient carriage was found to be more common than persistent carriage among patients with asymptomatic carriage of toxigenic Clostridioides difficile, though the burden of carriage was relatively higher among those with persistent carriage. These study findings were published in Clinical Infectious Diseases.

Researchers conducted a prospective study at 3 tertiary care facilities between November 2016 and November 2018 to identify patients with new-onset asymptomatic carriage of toxigenic C difficile and assess the natural history of C difficile infection and (CDI) colonization. Perirectal specimens were collected weekly for culture analyses from patients with no diarrhea at baseline, with those identified as asymptomatic carriers studied further to determine the duration and burden of carriage. Patients with only 1 positive culture were considered transient carriers and those with 2 or more positive cultures, collected at least 7 days apart, were considered persistent carriers. Fisher exact testing was used to compare the percentage of transient vs persistent carriers with a high burden of carriage, and factors associated with asymptomatic carriage were determined via bivariate analyses.

Among 1432 patients with negative cultures at baseline and at least 1 follow-up culture, asymptomatic carriage was noted in 142 (9.9%) and 39 (2.7%) developed CDI without prior carriage detection. Of the 142 asymptomatic carriers, 19 (13.4%) subsequently developed CDI. 

Data captured from 82 patients with asymptomatic carriage showed transient carriage in 50 (61.0%) and persistent carriage in 32 (39%). The estimated median time to clearance of colonization was 77 days. In addition, a high burden of carriage was observed among a significantly greater percentage of persistent vs transient carriers (56.3% vs 10.0%; P <.001).

Significant predictors for asymptomatic carriage of toxigenic C difficile were hospitalization within the past year, antibiotic exposure within the previous 90 days, chronic pulmonary disease, and methicillin-resistant Staphylococcus aureus carriage.

Study limitations include potential misclassification bias, the frequency of perirectal swab collection, and variations in the strategy used for patient enrollment across the 3 tertiary care facilities.

According to the researchers, “[O]ur findings suggest that if screening and isolation of asymptomatic carriers is implemented, recovery of C. difficile from multiple specimens should be required to avoid the potential for isolation of patients with transient, low-level carriage.”

Disclosures: One study author declared affiliations with pharmaceutical, biotech, and/or device companies. Please see the reference for a full list of authors’ disclosures.