Isolation for C. difficile Colonization in Hospitalized Patients
Yes, patients colonized with C. difficile should be placed on contact (enteric) precautions in the hospital, as asymptomatic carriers contribute significantly to transmission and environmental contamination. 1
Evidence Supporting Isolation of Colonized Patients
The 2019 World Society of Emergency Surgery guidelines explicitly recommend that C. difficile carriers should be placed in contact (enteric) precautions (Recommendation 1B). 1 This recommendation is based on compelling transmission data:
Transmission Risk from Colonized Patients
Asymptomatic carriers account for 29% of hospital-acquired CDI cases, demonstrating their substantial role as a reservoir for transmission. 1
Environmental contamination occurs in 34% of rooms housing colonized patients compared to 49% in rooms with active CDI patients—a clinically significant difference that still represents substantial contamination. 1
A 2022 prospective study confirmed that colonized patients contaminate 43% of their hospital rooms, particularly bathrooms (41% contamination rate), supporting the need for contact precautions especially when entering bathroom areas. 2
Patients who are roommates or neighbors of CDI patients have a 3.94-fold increased risk (95% CI 1.27-12.24) of acquiring C. difficile, highlighting the importance of preventing transmission from all C. difficile-positive patients. 1
Impact of Isolation on Transmission Rates
The most compelling evidence comes from an intervention study showing that screening for C. difficile colonization at admission combined with contact precautions reduced hospital-acquired CDI rates by 57% (from 6.9 to 3.0 per 10,000 patient-days; p<0.001). 1 The guidelines state this provides "the most convincing evidence to date for the significant effect of isolating asymptomatic carriers." 1
Practical Implementation
Isolation Specifications
Place colonized patients in a private room with en-suite hand washing and toilet facilities. 1
If private rooms are unavailable, cohort patients colonized with C. difficile in the same area, though recognize the theoretical risk of strain transfection. 1
Maintain contact precautions until resolution of any diarrhea (passage of formed stool for at least 48 hours). 1
Hand Hygiene Requirements
Hand hygiene with soap and water is mandatory—alcohol-based sanitizers do not kill C. difficile spores or remove them from hands. 1, 3
Healthcare workers must use soap and water after glove removal when caring for colonized patients. 1
Risk of Progression to Infection
Colonized patients face substantial infection risk:
Colonization increases the risk of subsequent CDI 5.9-fold (95% CI 4.21-8.16), with colonized patients having a 21.8% risk of developing infection versus 3.4% in non-colonized patients. 4
In ICU settings, colonization is an independent predictor of CDI with a relative risk of 8.62 (95% CI 1.48-50.25) for admission colonization and 10.93 for hospital-acquired colonization. 5
Important Caveats
Screening Not Routinely Recommended
While isolation of known carriers is recommended, routine screening for asymptomatic carriers and eradication is not indicated because colonization is not believed to be a direct independent precursor requiring treatment. 1 However, targeted screening in high-risk settings (as demonstrated in the intervention study) may be beneficial for infection control purposes. 1
Distinguishing Colonization from Infection
If a colonized patient develops diarrhea, this should be considered active CDI requiring treatment, not just colonization. 3 The presence of toxin-producing C. difficile in stool with diarrhea confirms CDI diagnosis. 3