Digestive Disorders Health Center

C. Diff: New Threat From Old Bug

Vancomycin to the Rescue?

As it happens, Zar had been studying the best way to treat C. diff infection when the current epidemic broke out. In a clinical trial, he's been comparing the currently recommended treatment for C. diff -- the antimicrobial drug Flagyl -- with a powerful antibiotic called vancomycin.

Vancomycin is known to work against C. diff. But doctors have been reluctant to use it -- not only because it costs more, but also because it's the last line of defense against a number of other nasty infections. Once it's in common use, it's only a matter of time before many of these germs become vancomycin resistant.

However, Zar's team reported to the IDSA that vancomycin cures severe C. diff disease 97% of the time -- compared with a 76% cure rate for Flagyl.

"Fortunately, we've seen no vancomycin resistance in C. diff -- yet," Zar says. "But we know that the bug can develop resistance to this antibiotic."

Community Infections Spreading

McDonald isn't yet ready to blame all of C. diff's resurgence on the bad new strain. Nor is the CDC yet sounding the alarm over the community spread of C. diff. But his CDC team has documented a growing problem.

Together with Duke University researchers, McDonald's CDC team analyzed more than 1,200 C. diff cases treated at six North Carolina hospitals.

"The general picture is that about one in five cases of C. diff in North Carolina hospitals were community-associated -- we think community-acquired -- in people not hospitalized for at least three months, most of them not for two years," he says.

That comes out to as many as 30 cases per 100,000 population per year -- as much as a threefold jump over previous rates. Even though doctors don't routinely report C. diff infections, the CDC has documented a sharp rise in cases. The latest statistics show that this increase continues to accelerate.

"This tells us that community-acquired C. diff is a lot more common than we would have thought," McDonald says. "In the past, we felt it was a prerequisite for people to have antibiotic exposure to get C. diff. And these community cases we looked at, over half had no antibiotic exposure. That is making a lot of us scratch our heads."

It may be that C. diff disease will become as big a problem as the current epidemic of drug-resistant staph infection.

"This epidemic is very concerning because it is so dynamic," McDonald says. "We are seeing a very steep curve upward in C. diff cases. Anything moving that quickly we need to address seriously -- and we are."

What to Do

McDonald and Zar stress two points. The first is that taking antibiotics is not without risk -- and one of the risks is C. diff disease.

The other point is that C. diff infection can be prevented -- by hand washing. Unfortunately, alcohol-gel hand sanitizers don't kill C. diff. McDonald and Zar warn anyone who has contact with a diarrheapatient to thoroughly wash their hands with soap and warm water.

Finally, McDonald and Zar warn people to be on the lookout for C. diff symptoms.

"If you get diarrhea that lasts more than three days, or if you get diarrhea accompanied by fever or blood in the stool, seek medical attention," McDonald says.