Clostridium difficile--a moving target.

Clostridium difficile has been recognized as a pathogen in humans for over 40 years, but in the past decade the incidence has increased and, more importantly, the clinical presentation and consequences have become more serious, with increased morbidity and mortality. The emergence of a new, more pathogenic strain, BI/NAP1/027, has driven these shifts. Treatment of this disease has been with two antibiotics, metronidazole and vancomycin, but increasing recurrence, not uncommon with C. difficile infections, has prompted research into several alternative therapies. These include a new class of antibiotic (fidaxomicin), a monoclonal antibody, a vaccine, and most recently a biotherapeutic (which, in this case, is a nontoxin-producing strain of C. difficile). The future management of C. difficile infection will probably require a combination of these approaches once we have the data from ongoing studies.