Diagnosing, Treating, and Preventing C. difficile infections


How is Clostridium difficile diagnosed?

 Biohazard Specimen bag (Taken by me)

Specimen container (Picture taken by me)If a patient in the hospital begins experiencing symptoms of C. difficile – associated disease (CDAD), his/her doctor will order a stool culture to be tested for C. difficile toxins. As a Certified Nursing Assistant at St. Joseph’s Hospital in Marshfield, WI (learn more on my About the Author page), I am responsible for obtaining at least 2 mL of a patient’s stool and putting it into a specimen container (shown on left). This container is labeled with pertinent patient information including medical history number, room number, and test to be performed. This labeled specimen container is placed into a biohazard bag (shown on right) and sent to a lab who performs one of many available C. difficile tests. Each test varies in terms of sensitivity, specificity, cost, turnaround time, and availability.



One of the most common C. difficile tests (and the one performed at St. Joseph’s Hospital in Marshfield, WI) is a two-step rapid immunochromatography method. The first step detects the presence of C. difficile bacteria. Since not all C. difficile bacteria are toxigenic, the second step involves detecting toxigenic strains of C. difficile. This is a rapid test with a turnaround time of less than one day and offers high sensitivity and specificity. The table below depicts the two-step algorithm; the entries in quotations indicate test results.


Two-Step Algorithm of Immunochromatography Method (Used with permission from Steven J. Thayer, 2009) 

                                         Used with permission from: Novicki, T.J. and T. R. Fritsche. 2009. The Changing Nature of

                                                                                        Clostridium difficile Disease and Laboratory Diagnosis.

                                                                                         Laboratory News 32: 1-4.



Other tests include enzyme immunoassays (EIA) and tissue cytotoxic assays. Enzyme immunoassays are fast, easy to use, and are commercially available. These tests detect the presence of antibodies to specific pathogenic C. difficile antigens.  Enzyme immunoassays offer lower sensitivity than other tests, and often times, if a tests appears negative for the toxins, a re-test is usually ordered. Tissue cytotoxic assays offer high sensitivity and specificity and are used as the gold standard of C. difficile testing; however, these tests have a 2 day turnaround time. The test works by detecting the presence of cytotoxic activity in the stool and confirming the presence of C. difficile toxins by using specific antitoxins.


A colonoscopy can also be performed to confirm pseudomembranous colitis. Doctors use a small camera, put in through the anus, to inspect the colon. Check out this video of a colonoscopy of a colon with pseudomembranous colitis and note the yellow patches (“pseudomembranes”) covering the colon. (Learn more about pseudomembranous colitis develops in the Pathology section.)


How is someone with toxigenic Clostridium difficile treated?


Usually, the first step in treatment a C. difficile infection is to stop the antibiotic that helped to cause the infection; however, sometimes this cannot be done depending on what the initial antibiotic was treating. Sometimes mild cases of CDAD do not require any further treatments. Though typically, antibiotics are used to treat CDAD. Oral metronidazole is used to treat mild CDAD, and vancomycin is used to treat severe CDAD. Antibiotics are usually given for about ten days. These antibiotics can also be given intravenously. Since oral vancomycin can lead to vancomycin resistance, metronidazole is usually tried first for all CDAD infections. Usually plenty fluids (oral or intravenous) are given to the patient to help re-hydrate the patient from the fluids lost from the diarrhea.


Symptoms usually ease within 2-3 days after stopping the first antibiotic and beginning a metronidazole or vancomycin regimen.


In patients with severe cases of pseudomembranous colitis, surgery may be performed to remove the infected portion of the colon.


How are Clostridium difficile infections prevented and the spread of infections prevented?


Once a patient has been diagnosed with toxigenic C. difficile, the patient is put under “Contact Precautions” to prevent the spread of C. difficile to other patients.

Picture of me in a gown & gloves. (Taken by co-worker)

Once the infected patient has been free from diarrhea for at least two days, the patient will be removed from "Contact Precautions" and put back on "Standard Precautions" (handwashing before entering/ leaving room).


HANDWASHING IS THE SINGLE MOST IMPORTANT WAY TO PREVENT INFECTION AND THE SPREAD OF INFECTION—it removes C. difficile spores (to find out how the spores form, check out the general characteristics page) from the hands. Using alcohol-based rubs will not remove the spores, so wash your hands!!!

 How to thoroughly wash your hands:


                                                         1. Wet your hands; then apply soap.

Wash between fingers. (Picture of my hands, Taken by my friend) 2. Rub the soap lather all over your hands.

Don't forget to wash fingernails, as well.  (Picture of my hands, Taken by my friend) 3. Wash all surfaces of your hands and fingernails, vigorously for 15 seconds.

Remember to point hands down when rinsing.  (Picture of my hands, Taken by my friend)4. Point your hands down as you rinse all the soap off.

Dry hands with a clean paper towel.  (Picture of my hands, Taken by my friend)5. Dry your hands with a clean, disposable paper towel.

Remember to turn off faucet with a paper towel. (Picture of my hands, taken by friend)6. Turn off the faucet with a paper towel to avoid re-contaminating your hands.



In addition to handwashing, thorough cleaning of the patent’s room after discharge is vital to preventing the spread of C. difficile infections to the next patient who stays in that room. Since C. difficile spores can survive routine environmental cleaning, rooms of C. difficile patients must be cleaned with a 10% sodium hypochlorite solution (NaClO, more commonly known as bleach).





Now that you know how C. difficile is diagnosed, treated, and prevented, you should see where all this information came from.