Mayo Clinic researchers have found that a sometimes deadly stomach bug, Clostridium difficile, is on the rise in outpatient settings. Clostridium difficile is a serious bacterium that can cause symptoms ranging from diarrhea to life-threatening inflammation of the colon. These findings were presented today at the 2009 American College of Gastroenterology (ACG) Annual Meeting in San Diego.
“Recent reports have shown increasing incidence and severity of C. difficile infection — especially in the older population,” says Darrell Pardi, M.D., Mayo Clinic gastroenterologist and senior author on the study. “Our study examines why the cases are on the rise and who is getting the infection.”
In this population-based study, researchers reviewed 385 cases of C. difficile bacterial infection from 1991 to 2005 to determine how many cases were hospital-acquired versus community-acquired infections. Of the cases, 192 were hospital-acquired, and 35 occurred in residents of nursing homes. Of these hospital-acquired cases, the median age of infection was 72 years; in contrast, 158 cases were community-acquired and the median age was 50 years. Thirty-five percent of the hospital infections resulted in a severe illness, compared to 22 percent of community infections that caused severe illness.
The patients with community-acquired infection were also less likely than the hospital-acquired group to have been exposed to antibiotics before their infection. Thus, many of the community-acquired infections lacked the traditional risk factors for infection, namely recent hospitalization and exposure to antibiotics.
According to the Centers for Disease Control and Prevention, each year in the United States, C. difficile is responsible for tens of thousands of diarrhea cases and at least 5,000 deaths.
Below is a link to an edited youtube video with Dr. Pardi discussing this study.


