In the early 1970s, clindamycin had only been on the market for a few years when patients taking the antibiotic began to present with diarrhea and associated colitis. Initial attempts to culture a pathologic organism were unsuccessful, so other possible pathophysiologic mechanisms, including medication toxicity, altered bacterial flora, or the emergence of a new bacterial or viral pathogen were considered. Patients were initially given treatments similar to those for ulcerative colitis, with systemic and topical steroids and colectomy. Several years later, Clostridium difficile infection (CDI) was identified as the culprit, and these presentations became increasingly common in U.S. hospitals, and later in community settings.
Incidentally, the organism had been discovered years earlier, in 1935, by a group of scientists studying normal bacterial flora in neonates, but it was not known to be pathogenic in adults. By 2007, CDI had become the most common cause of health care–associated infection in U.S. hospitals. This prompted the Centers for Disease Control and Prevention to begin active population- and laboratory-based surveillance for C. difficile through its Emerging Infections Program (EIP) with the goal of more accurately assessing disease burden, incidence, recurrence, and mortality by capturing data across the spectrum of health care delivery settings. The April 2015 issue of GI & Hepatology News highlighted a report of 2011 CDC data from 10 EIP sites (N Engl J Med. 372;9:825-34), demonstrating that CDI was responsible for nearly half a million infections and 29,000 deaths in that year across sites, with the hypervirulent NAP1 strain found to be more prevalent among health care–associated than community-associated infections.
Treatment of CDI continues to evolve. With increased use of fecal microbiota transplantation, emerging evidence regarding the efficacy of other novel therapies such as the monoclonal antibodies actoxumab and bezlotoxumab (providing passive immunity to toxins A and B, respectively), and development of preventive vaccines (currently in phase 2 trials), there is hope on the horizon of being able to improve patient outcomes and reduce the burden of CDI on the health care system.
Megan A. Adams, MD, JD, MSc, is a clinical lecturer in the division of gastroenterology at the University of Michigan, a gastroenterologist at the Ann Arbor, Mich., VA, and an investigator in the VA Ann Arbor Center for Clinical Management Research. She is an associate editor of GI & Hepatology News.
