Diagnosing, Treating, and Preventing C. difficile infections
How is Clostridium difficile diagnosed?
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
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.
- Patients with C. difficile are put into a single room with a sign outside their rooms indicating "Contact Precautions".
- Before healthcare providers enter the room, they are required to put a gown and gloves on (as shown on the right). When leaving the room, the gown and gloves are removed, and the healthcare provider washes his/her hands well.
- Patients are asked to stay in their room as much as possible.
- Reusable equipment from the isolated room must be thoroughly cleaned and appropriately disinfected before re-use—toilet, bed, bedside table, stethoscope, call light, etc.
- Visitors are not required to gown and glove but are asked to thoroughly wash their hands before leaving the patient’s room.
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!!!
1. Wet your hands; then apply soap.
2. Rub the soap lather all over your hands.
3. Wash all surfaces of your hands and
fingernails, vigorously for 15 seconds.
4. Point your hands down as you rinse
all the soap off.
5. Dry your hands with a clean, disposable paper
towel.
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.