Intestinal Superbug: A Serious Health Care Threat

In recent years, healthcare-associated infections—illnesses you acquire during a stay in a hospital or long-term care facility—have reached epidemic proportions. One of the most widespread and potentially serious of these illnesses is caused by the bacterium Clostridium difficile, often simply called C. diff, which is responsible for tens of thousands of cases of diarrhea and at least 5,000 deaths in the United States each year. And the problem is getting worse. According to a new study, the number of people hospitalized with this intestinal superbug has been growing by more than 10,000 cases a year. Dr. L. Clifford McDonald, a CDC expert said, "The nature of this infection is changing; it's more severe."

These bacteria are everywhere; in soil, water, air, human and animal feces, and on most surfaces. Although difficult to kill with most conventional household cleaners and antibacterial soaps, they don't create problems until they grow in abnormally large numbers in the intestinal tract of people taking antibiotics or other antimicrobial drugs. This most often occurs in healthcare settings such as hospitals and nursing homes where germs spread easily and people are especially vulnerable to infection. However, C. diff isn't confined exclusively to hospitals and nursing homes, and is increasingly showing up in otherwise healthy people who haven't been in the hospital or taken antibiotics. It is not clear how these low-risk people become infected.

Some people who are infected with C. diff never become sick, but can still spread the infection. Others have bouts of watery diarrhea, often with nausea and abdominal pain and cramping. And an increasing number of people develop colitis or pseudomembranous colitis; severe inflammations of the colon. Symptoms of these potentially fatal illnesses include:

• Fever, often greater than 101 F
• Profuse, watery diarrhea; 10 or more bowel movements a day
• Abdominal pain, which may be severe
• Blood or pus in the stool
• Nausea
• Dehydration
• Weight loss

Although the infection can usually be controlled with antibiotics, aggressive strains of C. diff are now emerging that not only resist treatment with common medications but work against other colon bacteria and produce far more deadly toxins than ordinary strains do. The result: Patients take those antibiotics + competing bacteria die off = C. diff explodes.

The study found C. diff played a role in close to 300,000 U. S. hospitalizations in 2005, more than double the number in 2000, before which this resistant strain of C. diff was rarely seen. The study also concluded that 2.3 percent of the cases in 2004 were fatal, approximately 5,500 deaths, nearly double the percentage of death related cases in 2000. Dr. Marya Zilberberg, a University of Massachusetts researcher and lead author of the study, says there are other factors playing into the rise of C. diff cases, including a larger number of patients who are older and sicker and "some overuse and inappropriate use of antibiotics." She added that many of the people who died also had other health problems. In Canada, C. diff has become an acute health concern, recently being blamed for 260 deaths at seven Ontario hospitals as well as 2,000 deaths in Quebec since 2002.

The Association for Professionals in Infection Control and Epidemiology are currently collaborating with U.S. hospitals to study the risk factors for C. diff-associated disease for this and other strains, as well as environmental disinfection strategies. Kathy Warye, the associations' chief executive said, "This is not a time for alarm, but more a time for educating health professionals to understand this particular pathogen."

The Zilberberg study was based on a sample of more than 36 million annual discharges from non-governmental U.S. hospitals and is being published in the June issue of Emerging Infectious Diseases, a CDC publication.