Epidemiology and outcomes of Clostridium difficile infections in hematopoietic stem cell transplant recipients.

Background. Clostridium difficile is the leading cause of infectious diarrhea among hospitalized patients and is a major concern for patients undergoing hematopoietic stem cell transplantation (HSCT). Risk factors and the natural history of C. difficile infection (CDI) are poorly understood in this population. Methods. We performed a retrospective nested case-control study to describe the epidemiology, timing, and risk factors for CDI among adult patients who received HSCTs at our center from January 2003 through December 2008. Results. The overall 1-year incidence of CDI was 9.2% among HSCTs performed (n = 999). The median time to diagnosis of CDI was short among both autologous and allogeneic HSCT recipients (6.5 days and 33 days, respectively). Risk factors for CDI in allogeneic HSCT recipients included receipt of chemotherapy prior to conditioning for HSCT, broad-spectrum antimicrobial use, and acute graft-versus-host disease (GVHD; adjusted odds ratio [AOR], 4.45; 95% confidence interval [CI], 1.54-12.84; P = .006). There was a strong relationship between early CDI and subsequent development of gastrointestinal tract GVHD in the year following allogeneic HSCT (P < .001). Gastrointestinal GVHD was also strongly associated with an increased risk for recurrent CDI (AOR, 4.23 [95% CI, 1.20-14.86]; P = .02). Conclusions. These results highlight the high incidence and early timing of CDI after HSCT. Early timing, coupled with the noted risk of pretransplant chemotherapy, suggests that the natural history of disease in some patients may involve colonization prior to HSCT. A potentially important interplay between CDI and GVHD involving the gastrointestinal tract was observed.