C. diff: Facts for Clinicians

Key points

  • Clostridioides difficile (C. diff) is a common cause of antibiotic-associated diarrhea (AAD). It accounts for 15 to 25% of all events of AAD.
  • Prevent C. diff infections (CDI) by appropriately using antibiotics and implementing infection control recommendations to prevent transmission.
  • Use EPA-registered disinfectants (List K) in patient-care areas, as appropriate.


C. diff is a spore-forming, Gram-positive anaerobic bacillus that produces two exotoxins: toxin A and toxin B.

Risk factors

  • Antibiotic exposure (especially fluoroquinolones, third or fourth generation cephalosporins, clindamycin, carbapenems).
  • Gastrointestinal surgery or manipulation.
  • Long length of stay in healthcare settings.
  • A serious underlying illness.
  • Immunocompromising conditions.
  • Advanced age.

How it spreads

C. diff sheds in feces. Any surface, device or material that becomes contaminated with feces could serve as a reservoir for the C. diff spores. Examples include:

  • Commodes
  • Bathtubs
  • Electronic rectal thermometers

C. diff spores can transfer to patients by the hands of healthcare personnel who have touched a contaminated surface or item.

Clinical features

  • Watery diarrhea
  • Fever
  • Loss of appetite
  • Nausea
  • Abdominal pain or tenderness


Patients with CDI exhibit clinical symptoms and test positive for the C. diff organism or its toxin.

Colonization vs infection

Colonization with C. diff is more common than infection. Colonized patients do not have disease caused by C. diff and often exhibit NO clinical symptoms (asymptomatic) like diarrhea. Colonized patients do test positive for the C. diff organism or its toxin.

Treatment and recovery

If a patient has had three or more stools in 24 hours:

  • Isolate patients with possible C. diff immediately, even if you only suspect CDI.
  • Order a C. diff test if other etiologies of diarrhea such as stool softener or laxative were not used.
  • Wear gloves and a gown when treating patients with potential infectious diarrhea, including C. diff, even during short visits. Gloves are important because hand sanitizer doesn't kill C. diff. In addition, handwashing alone may not be sufficient to eliminate all C. diff spores.
  • Reassess appropriateness of antibiotics in C. diff patients.

If CDI is confirmed:

  • Continue isolation and contact precautions.
  • Use antibiotics appropriately.
  • Clean room surfaces daily with an EPA-approved spore-killing disinfectant while treating a C. diff patient or upon their discharge or transfer.
  • When a patient transfers, notify the new facility if the patient has or had a C. diff infection. (Interfacility Infection Control Transfer Form)

In about 20% of patients, CDI will resolve within two to three days of discontinuing the antibiotic to which the patient was previously exposed. However, CDI should usually be treated with an appropriate course (about 10 days) of treatment, including oral vancomycin or fidaxomicin. After treatment, repeat C. diff testing is not recommended if the patient's symptoms have resolved, as patients often remain colonized.


  • Pseudomembranous colitis (PMC)
  • Toxic megacolon
  • Perforations of the colon
  • Sepsis
  • Death (rarely)

How to clean and disinfect potentially contaminated surfaces and devices

Surfaces should be clean and body substance spills should be managed promptly, per CDC's Guidelines for Environmental Infection Control in Health-Care Facilities. Routine cleaning should be performed before disinfection. EPA-registered disinfectants with a sporicidal claim have been successful in environmental surface disinfection of patient-care areas where surveillance and epidemiology indicate ongoing transmission of C. diff.

Note: EPA-registered disinfectants (List K) are recommended for patient-care areas. When choosing a disinfectant, check product labels for inactivation claims, indications for use and instructions.

What CDC is doing

CDC works with federal and public health partners to reduce C. diff infections. CDC also discovers, implements and evaluates innovative ways to improve healthcare quality and patient safety.

Keep Reading: C. diff Initiatives


Improving Diagnosis and Management: Clinical Practice Guidelines for Clostridium difficile Infection in Adults and Children: 2017

Federal Initiatives to Reduce C. diff: