Purpose of review: The aim of this article is to report recent changes in the epidemiology of Clostridium difficile associated disease.
Recent findings: An epidemic of Clostridium difficile associated disease in Quebec was associated with a threefold increase in incidence and a sharp increase in fatalities. Strain typing of C. difficile isolates from the involved hospitals revealed that 82% were of a single strain (NAP1/027). This strain was found to produce greater than 10 times as much toxin A and toxin B as historic isolates and has been identified in many institutions throughout North America and Europe. Frequent nosocomial use of fluoroquinolones may encourage the spread of this strain as it is fluoroquinolone resistant. An increased rate of community-acquired Clostridium difficile-associated disease has also been noted and, in some cases, without prior antibiotic exposure. Although some studies have suggested an increased failure rate of metronidazole in Clostridium difficile associated disease, it remains the recommended first line treatment for uncomplicated cases. Other antibiotics, a toxin binder, probiotic agents and a vaccine are being tested in clinical trials for efficacy in prevention and treatment of Clostridium difficile associated disease.
Summary: The recent increase in the incidence and severity of Clostridium difficile associated disease may be related, at least in part, to the emergence of a highly virulent, fluoroquinolone-resistant, NAP1/027 strain.