Clostridium 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) and accounts for 15 percent to 25 percent of all episodes of AAD.
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.
C. difficile causes diarrhea and more serious intestinal conditions such as pseudomembranous colitis (PMC), toxic megacolon, perforations of the colon, sepsis and in some cases, death. The symptoms of C. difficile disease include watery diarrhea, fever, loss of appetite, nausea and abdominal pain/ tenderness.
An individual is considered to be colonized with C. difficile if the patient exhibits no clinical symptoms; tests positive for C. difficile organism and/or its toxin more common than C. difficile-associated disease; and has C. difficileassociated disease. An individual is considered to be infected with C. difficile if he or she exhibits clinical symptoms the patient tests positive for the C. difficile organism and/or its toxin.
There are several laboratory tests used to diagnose C. difficile-associated disease. Stool culture for C. difficile 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 to 96 hours of the test. Antigen detection for C. difficile involves rapid tests (less than an hour) that detect the presence of C. difficile antigen by latex agglutination or immunochromatographic assays. They must be combined with toxin testing to verify diagnosis. 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. Tissue culture cytotoxicity assay detects toxin B only. This assay requires technical expertise to perform, is costly, and requires 24 to 48 hours 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 two 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.
In approximately one-quarter of patients, C. difficile-associated disease will resolve within two to three 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.
C. difficile-associated disease can be prevented in healthcare settings by taking the following actions:
Use antibiotics judiciously Use Contact Precautions:
For patients with known or suspected C. difficile-associated disease: