Shedding of Clostridioides difficile was found to be more effectively reduced with fidaxomicin therapy compared with vancomycin and metronidazole, according to results of a prospective, randomized trial published in Clinical Infectious Diseases.

Hospitalized patients (N=31) diagnosed with C difficile infection between 2014 and 2017 were randomly assigned to receive either oral metronidazole 500 mg every 6 hours (n=10), oral vancomycin 125 mg every 6 hours (n=10), or oral fidaxomicin 200 mg every 12 hours (n=11) for at least 10 days. C difficile shedding was assessed in patient stool and on 5 high-touch surfaces.

The median age of patients was 61 years (interquartile range [IQR], 55-70); 48% were women.

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C difficile was detected on at least 1 surface for most patients (74%). Surfaces found to be contaminated most frequently included the bathroom floor (27.0%) and toilet (17.7%). Contamination varied on the basis of antibiotic therapy; patients on metronidazole had the highest contamination rate (21.4%; 95% CI, 18.0-25.2), followed by fidaxomicin (13.1%; 95% CI, 10.7-15.9; P =.04) and vancomycin (6.3%; 95% CI, 4.7-8.3; P <.01).

Baseline C difficile shedding was associated with environmental contamination (odds ratio [OR], 1.99; 95% CI, 1.35-2.93 per log10 colony forming units [CFU]/g stool; P <.01). Only patients receiving fidaxomicin therapy were found to be associated with reductions in environmental contamination over time (OR, 0.83; 95% CI, 0.70-0.99; P =.04).

In stool, shedding declined more rapidly among patients on fidaxomicin (-0.36; 95% CI, -0.52 to -0.19 per log10 CFU/g stool; P <.01) or vancomycin (-0.17; 95% CI, -0.34 to -0.01 per log10 CFU/g stool; P =.05) compared with metronidazole (-0.01; 95% CI, -0.10 to 0.08 per log10 CFU/g stool).

Most patients were infected with a single ribotype (92.6%), and 88.8% of patients were infected with the ribotype detected in their room.

This study may have been limited by its small sample size and unblinded design.

These data indicate that C difficile shedding and environmental contamination were more greatly reduced with fidaxomicin compared with metronidazole or vancomycin therapies.

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


Turner NA, Warren BG, Gergen-Teague MF, et al. Impact of oral metronidazole, vancomycin, and fidaxomicin on host shedding and environmental contamination with Clostridioides difficile. Clin Infect Dis. Published online May 21, 2021. doi:10.1093/cid/ciab473