Clostridium difficile Testing and Treatment
Colonization and Infection
- Asymptomatic colonization is present when the patient’s stool tests positive for C. difficile and/or its toxins (A and/or B) in the absence of clinical symptoms.
- Asymptomatic colonization with C. difficile is more common than C. difficile infection (CDI) and in most cases, should not be treated.
- CDI is present when a patient tests positive for toxigenic C. difficile bacteria and clinical symptoms of infection are present.
- Only watery or unformed stools should be collected and tested
- Testing asymptomatic patients is not clinically useful, and may lead to the use of unnecessary antibiotics
- Repeat testing during the same episode of diarrhea is not recommended
- “Test of cure” is not recommended
- Retest after completion of treatment only if signs and symptoms of infection continue.
- Avoid routine testing of children <1 year of age
- Testing for children 1-3 years can be considered, but testing for other causes of diarrhea (e.g. viral) is recommended first
- Children >3 years can be tested in the same manner as older children and adults
- For all testing and treatment recommendations in infants and children, refer to the American Academy of Pediatrics Policy Statement.
Storage and handling of specimens
- Specimens should be submitted in a clean, watertight container. Transport media is not necessary.
- Specimens should be transported as soon as possible and stored at 2°C to 8°C until tested.
- C. difficile toxin degrades at room temperature in as short as 2 hours
- False-negative results occur when specimens are not properly handled or stored properly
- Laboratory Tests for Clostridium difficile Infection (PDF 124KB/1 page)
Testing table summary.
- Clostridium difficile Infection (CDI) Testing Recommendations: Recommendations for stool collection and submission (PDF: 110KB/1 page)
Do's and don'ts for Clostridium difficile testing.
- Asymptomatic patients should not be treated with antibiotics
- Symptoms resolve in approximately 20% of patients after discontinuing the inciting antibiotic
- Therapeutic necessity of the inciting antibiotic should be reviewed before stopping
- If symptoms do not resolve within 2-3 days after the discontinuation of the inciting antibiotic, CDI testing should occur and administration of an appropriate course of antibiotics is recommended if the test is positive for C. difficile and its toxins
- Metronidazole (oral and intravenous) or oral vancomycin are most commonly recommended
- New information shows that fidaxomicin performs as well as vancomycin for the treatment of mild to moderately severe CDI; consider consulting an infectious disease practitioner to discuss treatment options
- For treatment recommendations including dosage and duration, refer to the SHEA/IDSA guidelines, link available below
- If possible, avoid the use of antiperistaltic agents as they may obscure symptoms and precipitate toxic megacolon
- Administration of currently available probiotics is not recommended to prevent primary CDI, as there is limited data to support this approach and there is a potential risk of bloodstream infection
- Performing a “test of cure” is NOT recommended; only retest a patient if symptoms persist or return within 10 days of starting treatment
- SHEA Guidelines and White Papers
For treatment recommendations refer to the SHEA guidelines. Attention: Non-MDH link
- Clostridium difficile Infection in Infants and Children: Policy Statement
For CDI testing and treatment recommendations for infants and children refer to the American Academy of Pediatrics policy statement. Attention: Non-MDH link
- MDH staff are available to provide clinical consultation regarding diagnosis and management of C. difficile. Call 651-201-5414 (toll free 1-877-676-5414).