Growing concerns of 'Cdiff' bacteria
By the faculty of Harvard Medical School for The Harvard Medical School Adviser

Q: My mother was recently hospitalized with serious intestinal problems after taking antibiotics. Her doctor said that her severe abdominal pain and diarrhea were caused by a bacterium called C. difficile. I'd never heard of this before. How did she get it -- and can I catch it from her?

A: Most people aren't familiar with Clostridium difficile (also known as or C. difficile or just "C diff "). In fact, these bacteria are common in soil and water. They even live in the colons of 3 percent of healthy adults. Most of the time, C. difficile doesn't cause problems. But under the right circumstances, some strains of the organism can produce toxins that attack the cells lining the colon. In most cases, this occurs when people take antibiotics, which upsets the balance of normal, healthy bacteria in the intestines (see illustration).

The resulting symptoms can range from mild diarrhea to severe inflammation of the colon, a condition known as colitis. In extreme cases, people develop lifethreatening complications, such as a greatly distended colon that may burst. Rarely, surgery to remove the colon may be needed.

Doctors have known about C. difficile-related diarrhea and colitis since the 1970s. Until recently, the problem was uncommon. It usually occurred in people ages 65 and older in hospitals and long-term care facilities. Clinicians have been able to control the problem with infection-control measures, care in choosing antibiotics and proven treatments.

But lately, C. difficilerelated illness has become more common. It has also become harder to treat and seems to be affecting more people outside the usual risk groups. Adding to the concern, scientists have identified a new, more virulent strain of the bacterium.

People are most likely to encounter C. difficile in the hospital, where 20 percent to 40 percent of patients are colonized with the organism. The bacterium is excreted in the feces of infected people. These may include C. difficile carriers who don't have diarrhea but are hospitalized for unrelated reasons. The bacteria form hard-to-kill spores. These spores can survive for months on floors, furniture, sinks, bedpans, toilet seats and stethoscopes. Patients and visitors may pick up the spores on their hands and inadvertently transfer them to their mouths. Spores can also be spread on the hands and clothing of health care workers.

Patients who are older, spend more time in the hospital, and who've been treated with certain powerful antibiotics face the highest risk of developing a C. difficile-associated illness. Abdominal surgery, serious underlying illnesses and immune-system problems can also raise the risk. But cases are now cropping up in people who have never been hospitalized.

About 20 percent of patients get better within a week or two of stopping the antibiotic that sparked the disease. But most people need medical treatment, usually a 10-day course of an antibiotic that can kill C. difficile. Doctors usually prescribe metronidazole (Flagyl) and vancomycin (Vancocin). Unfortunately, some patients relapse after treatment and need more therapy.

Most people exposed to C. difficile will not get sick from it, nor will most people who take antibiotics. But you can help limit the spread of this emerging troublemaker by following some simple precautions to protect yourself and others.

Hand washing with soap and water is one of the best ways to stop the spread of C. difficile. While alcohol-based hand rubs may be better for other critters, soap and water are best for C. diff. If you or a loved one is in the hospital, insist on careful hand hygiene from hospital staff. If you visit a hospital or other health care facility, be sure to wash your hands thoroughly with soap and water for at least 15 to 20 seconds before you eat, visit with another patient, or leave the facility.

Most antibiotic-associated diarrhea isn't caused by C. difficile but rather by the antibiotic's effect on normal digestion. Symptoms usually aren't severe and improve shortly after the drug is stopped. But C. difficile is responsible for most cases of antibiotic-associated colitis. If you develop serious diarrhea, see your clinician promptly, particularly if you have abdominal pain or fever.

C. difficile is yet another reason to avoid taking unnecessary antibiotics. Don't ask your clinician for antibiotics to treat a cold or simple respiratory illness. Antibiotics are of no use in treating most such diseases anyway. When taking an antibiotic, take it exactly as prescribed. Antibiotics are marvelous drugs. But like all medical treatments, they can produce side effects. Still, prudent prescribing and proper precautions can make C. diff less difficult.

Copyright 2007 the President and Fellows of Harvard College. Developed by Harvard Health Publications (www.health.harvard.edu). Distributed by UFS. Submit q u e s t i o n s t o harvard_adviser@hms.harv ard.edu.