Should a patient with a positive nucleic acid test result for C. difficile (Clostridioides difficile) be put in isolation?

Isolation for C. difficile Positive Nucleic Acid Test

Yes, patients with a positive nucleic acid test for C. difficile should be placed on contact precautions immediately, ideally in a private room, and these precautions should be maintained until hospital discharge if your institution has high CDI rates. 1

Immediate Isolation Requirements

Place the patient on preemptive contact precautions as soon as CDI is suspected, even before test results return. 2 This is critical because:

• Patients suspected of CDI have a 20% positivity rate, yet test results take an average of 2.07 days to return 2
• Skin contamination occurs in patients with CDI, allowing healthcare personnel hands to become contaminated after routine patient contact 2
• Environmental contamination is present in 49% of rooms with active CDI patients 1, 3

Contact Precautions Protocol

Healthcare personnel must implement the following measures when caring for C. difficile-positive patients:

• Use gloves and gowns on entry to the room and throughout patient care (strong recommendation, high-quality evidence) 2
• Perform hand hygiene with soap and water, NOT alcohol-based sanitizers, as alcohol does not eliminate C. difficile spores 1, 3
• Place patient in a private room with dedicated bathroom facilities 2, 3

Duration of Isolation

The duration depends on your institution's CDI rates:

High CDI Rate Institutions

Continue contact precautions until hospital discharge, regardless of symptom resolution 1. This strong recommendation is based on:

• Patients continue shedding C. difficile spores even after diarrhea resolves 1
• 56% of patients still have detectable C. difficile in stool 1-4 weeks post-treatment 2
• Environmental contamination remains high (60% skin, 37% environment) even when diarrhea resolves 2

Standard CDI Rate Institutions

Maintain contact precautions for at least 48 hours after diarrhea has ceased (passage of formed stool) 2. However, the IDSA/SHEA 2018 guidelines emphasize that prolonging precautions until discharge is preferred if CDI rates remain problematic 1.

Room Assignment Priorities

When private rooms are limited, prioritize single-room isolation for patients with: 2

• Fecal or urinary incontinence
• Continuous wound secretions
• Use of invasive devices/equipment

If cohorting is necessary, only cohort patients with CDI together—do not mix with patients who have other multidrug-resistant organisms like MRSA or VRE 2. This prevents cross-transmission of different pathogens.

Environmental Decontamination

• Use sodium hypochlorite (bleach) solutions for environmental cleaning, as standard disinfectants do not eliminate spores 3
• Daily to twice-daily disinfection of high-touch surfaces reduces CDI rates by 45-85% 3
• Ensure terminal cleaning with bleach when isolation is discontinued 1

Special Considerations

Patients with ileus or toxic megacolon require strict contact precautions even without diarrhea, as they remain highly contagious despite the absence of diarrheal symptoms 1.

Asymptomatic Carriers (Colonization Without Symptoms)

If the positive test is from screening rather than symptomatic disease:

• Place colonized patients in contact precautions, as they contribute to 29% of hospital-acquired CDI cases 3
• Environmental contamination occurs in 34% of rooms with colonized patients 3
• Roommates of CDI patients have a 3.94-fold increased risk of acquiring C. difficile 2, 3
• However, routine screening and eradication of asymptomatic carriers is not recommended 2, 3

Common Pitfalls to Avoid

• Do not assume absence of diarrhea means absence of contagiousness—spore shedding continues after symptom resolution 1
• Do not use alcohol-based hand sanitizers as primary hand hygiene—they are ineffective against spores 1, 3
• Do not discontinue precautions prematurely in high-CDI-rate institutions—this increases transmission risk 1

Impact of Proper Isolation

When implemented correctly, contact precautions combined with screening reduce hospital-acquired CDI rates by 57% (from 6.9 to 3.0 per 10,000 patient-days) 3. Non-infected patients who are roommates or neighbors of CDI patients face significantly elevated transmission risk without proper isolation measures 2.