Article

What is Clostridium difficile (C. difficile)?

By CDC

C. difficile is a spore-forming, gram-positive anaerobic bacillus that produces two exotoxins: toxin A and toxin B. It is a common cause of antibiotic-associated diarrhea (AAD). It accounts for 15-25% of all episodes of AAD.

What are C. difficile-associated diseases?

They are diseases that result from C. difficile infections including:

pseudomembranous colitis (PMC)
toxic megacolon
perforations of the colon
sepsis
death (rarely)

What are the main clinical symptoms of C. difficile-associated disease?

Clinical symptoms include:

watery diarrhea
fever
loss of appetite
nausea
abdominal pain/tenderness

Which patients are at increased risk for C. difficile-associated disease?

The risk for disease increases in patients with:

antibiotic exposure
gastrointestinal surgery/manipulation
long length of stay in healthcare settings
a serious underlying illness
immunocompromising conditions
advanced age

What is the difference between C. difficile colonization and C. difficile-associated disease?

C. difficile colonization

patient exhibits NO clinical symptoms
patient tests positive for C. difficile organism and/or its toxin
more common than C. difficile-associated disease

C. difficile-associated disease

patient exhibits clinical symptoms
patient tests positive for the C. difficile organism and/or its toxin

Which laboratory tests are commonly used to diagnose C. difficile-associated disease?

Stool culture for C. difficile: This is the most sensitive test available, but the one most often associated with false-positive results due to presence of non-toxigenic strains. Stool cultures for C. difficile also are labor intensive and require the appropriate culture environment to grow anaerobic microorganisms. Results are available within 48-96 hours of the test.
Antigen detection for C. difficile: These are rapid tests (<1 hr) that detect the presence of C. difficile antigen by latex agglutination or immunochromatographicassays. They must be combined with toxin testing to verify diagnosis.
Toxin testing for C. difficile*:

          o Enzyme immunoassay detects toxin A, toxin B, or both A and B. It is a same-day assay but less sensitive than the tissue culture cytotoxicity assay.
          o Tissue culture cytotoxicity assay detects toxin B only. This assay requires technical expertise to perform, is costly, and requires 24-48 hr for a final result. It does provide specific and sensitive results for C. difficile-associated disease.
    * C. difficile toxin is very unstable. The toxin degrades at room temperature and may be undetectable within 2 hours after collection of a stool specimen. False-negative results occur when specimens are not promptly tested or kept refrigerated until testing can be done.

How is C. difficile transmitted?

C. difficile is shed in feces. Any surface, device, or material (e.g., commodes, bathing tubs, and electronic rectal thermometers) that becomes contaminated with feces may serve as a reservoir for the C. difficile spores. C. difficile spores are transferred to patients mainly via the hands of healthcare personnel who have touched a contaminated surface or item.

How is C. difficile-associated disease usually treated?

In 23% of patients, C. difficile-associated disease will resolve within 2-3 days of discontinuing the antibiotic to which the patient was previously exposed. The infection can usually be treated with an appropriate course (about 10 days) of antibiotics including metronidazole or vancomycin (administered orally). After treatment, repeat C. difficile testing is not recommended if the patients’ symptoms have resolved, as patients may remain colonized.

How can C. difficile-associated disease be prevented in hospitals and other healthcare settings?

Use antibiotics judiciously
Use Contact Precautions: for patients with known or suspected C. difficile-associated disease:

          o Place these patients in private rooms.If private rooms are not available, these patients can be placed in rooms (cohorted) with other patients with C. difficile-associated disease.
          o Perform Hand Hygiene using either an alcohol-based hand rub or soap and water. Note: If your institution experiences an outbreak, consider using only soap and water for hand hygiene when caring for patients with C. difficile-associated disease; alcohol-based hand rubs may not be as effective against spore-forming bacteria.
          o Use gloves when entering patients’ rooms and during patient care.
          o Use gowns if soiling of clothes is likely.
          o Dedicate equipment whenever possible.
          o Continue these practices until diarrhea ceases.

Implement an environmental cleaning and disinfection strategy:

          o Ensure adequate cleaning and disinfection of environmental surfaces and reusable devices, especially items likely to be contaminated with feces and surfaces that are touched frequently.
          o Use an Environmental Protection Agency (EPA)-registered hypochlorite-based disinfectant for environmental surface disinfection after cleaning in accordance with label instructions; generic sources of hypochlorite (e.g., household chlorine bleach) also may be appropriately diluted and used. (Note: alcohol-based disinfectants are not effective against C. difficile and should not be used to disinfect environmental surfaces.)
          o Follow the manufacturer’s instructions for disinfection of endoscopes and other devices.
          o Infection control practices in long term care and home health settings are similar to those practices taken in traditional health-care settings.

What can I use to clean and disinfect surfaces and devices to help control C. difficile?

Surfaces should be kept clean, and body substance spills should be managed promptly as outlined in CDC’s “Guidelines for Environmental Infection Control in Health-Care Facilities.” Hospital cleaning products can be used for routine cleaning. Hypochlorite-based disinfectants have been used with some success for environmental surface disinfection in those patient-care areas where surveillance and epidemiology indicate ongoing transmission of C. difficile. Consult the aforementioned guidelines for use conditions for generic sources of hypochlorite-based products (e.g., household chlorine bleach) for disinfection of environmental surfaces.

Note: EPA-registered hospital disinfectants are recommended for general use whenever possible in patient-care areas. At present there are no EPA-registered products with specific claims for inactivating C. difficile spores, but there are a number of registered products that contain hypochlorite. If an EPA-registered proprietary hypochlorite product is used, consult the label instructions for proper and safe use conditions.

[KaiScience editorial note: See also, Clostridium difficile - A Dangerous and Formidable Foe.]

Where can I get more information?

The Centers for Disease Control and Prevention also has General Information about C. difficile and more information about Gastrointestinal Infections in Heathcare Settings.

Additional Scientific References:

    * Boone N, Eagan JA, Gillern P, Armstrong D, Sepkowitz KA. Evaluation of an interdisciplinary re-isolation policy for patients with previous Clostridium difficile diarrhea. Am J Infect Control 1998;26:584–7.
    * CDC. Guidelines for environmental infection control in health-care facilities. MMWR 2003;52 (RR10):1–42. Also available at: http://www.cdc.gov/ncidod/hip/enviro/guide.htm.
    * CDC. Guidelines for hand hygiene in health-care settings. MMWR 2002;51 (RR16):1–45.
    * Johnson S, Gerding DN. Clostridium difficile-associated diarrhea. Clin Infect Dis 1998;26:1027–36.
    * Simor AE, Bradley SF, Strausbaugh LJ, Crossley K, Nicolle LE. SHEA Position Paper: Clostridium difficile in long-term-care facilities for the elderly. Infect Control Hosp Epidemiol 2002;23:696–703.
    * Gerding DN, Johnson S, Peterson LR, Mulligan ME, Silva J. SHEA Position Paper:Clostridium difficile-associated diarrhea and colitis. Infect Control Hosp Epidemiol 1995;16:459–77.
    * Poutanen, Simor AD. Clostridium difficile-associated diarrhea in adults. CMAJ 2004;171(1):51-8.

Comments

Only KaiShare partners are allowed to comment. Please sign-in to your KaiShare account to comment.

Comment by Andrew Bales on September 27th, 2008 at 1:46pm

Great information! Recently I spoke with a colleague who was considering implementing a "hypochlorite" based cleaning procedure for all patient rooms post-discharge, regardless of whether the patient was suspected of having C. diff. I am not sure if he was able to implement such protocol as there were some issues regarding hypochlorite based cleaners and people with sensitivity to such cleaning products. I would be interested to know if such a measure is truly necessary?

It is also my understanding (and here I believe the CDC validates such an understanding) that the first and potentially most important step in battling C. difficile spores is good surface cleaning (i.e., removing as many of the spores as possible from the environmental surface.)

I don't think the aforementioned point can be stressed enough. To disinfect using a bleach based products is counterproductive and ineffective if the surface has not first been properly cleaned.

Thanks for posting this summary by the CDC

-Andrew Bales C.E.H.

About CDC

The Centers for Disease Control and Prevention (CDC) is one of the 13 major operating components of the Department of Health and Human Services (HHS), which is the principal agency in the United States government for protecting the health and safety of all Americans and for providing essential human services, especially for those people who are least able to help themselves.

Since it was founded in 1946 to help control malaria, CDC has remained at the forefront of public health efforts to prevent and control infectious and chronic diseases, injuries, workplace hazards, disabilities and environmental health threats.