Current Concepts Clostridium difficile — More Difficult Than Ever

In 1935, Hall and O’Toole first isolated a gram-positive, cytotoxin-producing anaerobic bacterium from the stool of healthy neonates.1 They named it Bacillus difficilis to reflect the difficulties they encountered in its isolation and culture. We now face the opposite problem of being unable to contain the growth and spread of the same bacterium, now called Clostridium difficile, which is a frequent cause of infectious colitis, usually occurring as a complication of antibiotic therapy, in elderly hospitalized patients. In this article we review recent changes in the epi-demiology of C. difficile infection, discuss changes in disease severity and response to therapy, and review new approaches to the management of this increasingly problematic infectious diarrhea. Incidence a nd Se v er i t y During the mid- and late 1990s, the reported incidence of C. difficile infection in acute care hospitals in the United States remained stable at 30 to 40 cases per 100,000 population.2 In 2001, this number rose to almost 50, with subsequent in-creases to the point that the number of cases of C. difficile infection that were re-ported in 2005 (84 per 100,000) was nearly three times the 1996 rate (31 per 100,000). Of even greater concern are the increases in severe or fatal infection.3-5 In England, for example, C. difficile infection was listed as the primary cause of death for 49