News release: New study shows toll of Clostridium difficile infections, role of antibiotic overuse

News Release
February 25, 2015

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New study shows toll of Clostridium difficile infections, role of antibiotic overuse

MDH collaborated with others on national study published in Thursday's New England Journal of Medicine

The Minnesota Department of Health (MDH) has collaborated on a national study that sheds new light on the massive toll of Clostridium difficile - a bacterium that can cause severe, hard-to-treat diarrhea. The study, to be published in Thursday's edition of the New England Journal of Medicine, finds that Clostridium difficile caused an estimated 453,000 infections in the United States in 2011, and was associated with 29,000 deaths - many among vulnerable populations such as nursing home residents.

MDH was among 10 state health departments and universities contributing to the study, which reports that the burden of C. difficile infections (CDI) is greater than previously reported because earlier studies did not always include infections among patients in other health care settings such as outpatient clinics and nursing homes. More than 345,000 cases became ill outside of hospitals, highlighting the importance of prevention measures across the entire spectrum of health care, including nursing homes and outpatient facilities.

The study also found that the risk of CDI increases with age. One third of infections and more than 80 percent of deaths occurred in patients 65 years or older. More than 100,000 nursing home residents develop CDI each year.

Many of the infections could have been prevented with more appropriate prescribing of antibiotics, health officials said. Taking antibiotics is the most important risk factor for developing CDI. Antibiotics can alter beneficial bacteria normally present in the human intestine for several weeks to months. Altering intestinal bacteria puts patients at risk for CDI. More than half of all hospitalized patients will get an antibiotic at some point during their hospital stay, but studies have shown that 30-50 percent of antibiotics prescribed are unnecessary or incorrect. Unnecessary antibiotic use at one facility may lead to patients developing CDI and potentially spreading it to another facility when patients transfer, such as from a hospital to a nursing home.

The national estimates reported in this study are based on surveillance data collected from across diverse U.S. geographic locations, amounting to the largest such study to date. In Minnesota, the study involved four mostly rural counties in central Minnesota: Stearns, Benton, Todd and Morrison. In that region, the rate of community- associated infections, those patients who did not have an overnight stay in a hospital or nursing home, was significantly higher than in the other sites.

Dr. Stacy Holzbauer, epidemiologist and co-author of this research, said the reasons for Minnesota's higher rate of community-associated infections include:

  • More than 90 percent of Minnesota patients were tested using a more sensitive method, compared to 50 percent of patient tests in others states. This resulted in Minnesota detecting more cases, especially in outpatient settings.
  • Minnesota's study population was more rural than the other sites. Previous studies outside the U.S. have also shown higher rates of community-associated infections in rural areas.

In Minnesota, 80 percent of the community-associated cases had inpatient or outpatient health care exposures and 60 percent had taken antibiotics prior to illness onset. Minnesota researchers found that the most common reasons for antibiotics being prescribed in these patients were for upper-respiratory infections, dental procedures, and skin and urinary tract infections. Antibiotic use for these illnesses is a major driver for over prescribing.

The heavy burden of CDI, as demonstrated by this study, leads to an excess in health care costs that need to be brought under control, say health officials. Previous studies have estimated excess health care costs related to CDI to be up to $4.8 billion each year for hospitals alone.

"There is clearly a consequence to overprescribing of antibiotics," Holzbauer said. "C. difficile infections can be prevented through improved antibiotic stewardship, following recommended infection control practices and good communication between health care facilities." To prevent more cases of C. difficile, she and CDC say several things need to happen:

  • Health care providers need to prescribe and use antibiotics carefully, isolate patients with CDI immediately, and when a patient is transferred, notify the new facility if the patient has CDI.
  • Patients should take antibiotics only as prescribed by your health care provider and complete the prescribed course of treatment. Tell your health care provider if you develop diarrhea after taking antibiotics. Wash your hands before eating and after using the bathroom.
  • Health care facilities should support better testing, tracking and reporting of CDI and support prevention efforts.

MDH, in partnership with health care providers and facilities, has been at the forefront of efforts to promote antibiotic stewardship, particularly in acute care health care settings. Prevention programs developed have included:

  • Partnerships with the Minnesota Hospital Association, StratisHealth (the state's quality improvement organization), Association for Professionals in Infection Control and Epidemiology, and others interested in reducing health care associated infections, including CDI.
  • Infection prevention and control resources for hospitals and long-term care facilities.
  • CDI information for patients and families.
  • An antimicrobial stewardship toolkit for long-term care facilities.
  • A guide for antimicrobial stewardship in hospitals.
  • An annual antimicrobial stewardship conference for health care providers.

More information on Clostridium difficile and the study can be found at:


Media inquiries:

Doug Schultz
MDH Communications