Clostridium difficile-associated disease in human stem cell transplant recipients: coming epidemic or false alarm?

Clostridium difficile is the most common cause of nosocomial diarrhea in the United States and Europe, and is a cause of significant morbidity and mortality among hospitalized patients. A newly identified epidemic strain has been associated with many hospital outbreaks of C. difficile-associated disease (CDAD), raising the concern of an escalating burden of CDAD among at-risk patients. Hematopoietic SCT (HSCT) recipients are known to be at increased risk for a wide variety of infectious complications, including CDAD as a result of prolonged hospitalizations, exposure to broad-spectrum antibiotics, altered integrity of the intestinal mucosa and GVHD. The incidence of CDAD in the HSCT population has been reported as high as 20% in some large series. The frequency and seriousness of CDAD in this defined group as compared with the general hospital population, however, are not clearly delineated. We discuss the epidemiology and diagnosis of CDAD and review recent studies examining the risk factors and characteristics of CDAD in HSCT recipients. Finally, we provide a management algorithm for the diagnosis and treatment of CDAD at our institution.