Division of Gastroenterology
A new “superbug?”
A report by the U.S. Centers for Disease Control and Prevention (CDC) has sparked stories about a new “superbug” that’s on the loose. The bug in question is the bacterial infection Clostridium difficile, which is more commonly referred to as “c-diff.”
But “superbug” may not be an entirely accurate term. In popular usage, the “superbug” is usually taken to mean germs that have become resistant to the drugs that had previously been able to control them. C-diff is a serious infection, but it is still one that, for the most part, can be controlled through existing therapies.
C-diff appears to be growing more common and more virulent, however. The CDC reported that, from 2000 to 2005, the incidence of hospitalizations due to c-diff doubled, from 5.5 cases per 100,000 people to 11.2 cases per 100,000 people. At the same time, fatalities due to c-diff rose from 1.2 percent to 2.2 percent. These are ominous trends, but it’s unclear if the increase in fatalities is related to the growing number of cases or to an increased virulence of the organism or to the potency of our newer antibiotics.
You may be surprised to learn that c-diff bacteria are not a new health threat. They exist naturally along with millions of others that live in, on or near your body. Some of these bacteria are “good” bacteria that enormously aid with body processes like digestion and with keeping in check those “bad” bacteria, like c-diff, that can cause illness.
Researchers used to think that everyone carried c-diff around in the compressed stool that exists in the colon and that c-diff was kept under control by “good” bacteria. The theory was that a c-diff infection occurs when an individual took antibiotics that killed off enough of their “good” bacteria to allow the c-diff bugs to take over. Newer evidence suggests that, even though more than half of everyone has had it at one time or another, perhaps only a small percentage of the population carries the c-diff bacteria at any one time.
C-diff is spread by spores in the feces. Unlike the bacteria itself, these spores appear able to survive for an extended time on dry surfaces outside the body. Because c-diff infections routinely occurred in hospitals or nursing homes, many health professionals assumed the transmission of the bacteria was linked to those environments. But, recent research has uncovered cases where transmission happened without any apparent connection to hospitals or nursing homes. In fact, there are some troubling indications that it is at least possible to transmit c-diff from food-producing animals to humans. CDC studies to verify or disprove this are underway.
The symptoms of a c-diff infection can include repeated watery diarrhea, fever, loss of appetite, nausea, abdominal pain abdominal distension and a peculiar elevation of the white blood cells may occur. Dehydration from c-diff is common. C-diff can also lead to a serious infection that causes conditions like colitis. Rarely, even perforations may complicate toxic megacolon and result in death.
Physicians usually prescribe specific types of antibiotics to treat cdiff. Despite c-diff’s “superbug” reputation, these antibiotics are generally effective, although one strain of the bacteria appears to have acquired some level of resistance, making treatment more difficult. Most patients will begin to recover within a few days of treatment. Nearly 20 percent of patients; however, will have another c-diff infection, often because of residual bacteria in the colon or because of re-infection from bacteria in the individual’s environment.