Clostridium difficile infection among hematopoietic stem cell transplant recipients: Beyond colitis

PURPOSE OF REVIEW: To review the most recent data regarding the epidemiology, risks factors, and outcomes among hematopoietic stem cell transplant recipients with Clostridium difficile infection (CDI). RECENT FINDINGS: With the emergence of an epidemic strain of C. difficile known as NAP1 in the early 2000s, rates of this infection have escalated globally. Hematopoietic stem cell transplant recipients appear to be one of the most vulnerable populations for the development of CDI. Traditional risk factors for CDI including antimicrobial exposure and older age are likely only a piece of the overall risk profile, with recent study results also emphasizing other factors such as transplant type, conditioning regimen, and graft-versus-host disease (GVHD). The relationship between CDI and subsequent development of GVHD, particularly of the gastrointestinal tract, is of specific interest. A bidirectional relationship of association has been highlighted in a number of recent studies and underscores the need for further prospective studies to address the potential indirect effects of alloreactivity induced by CDI. SUMMARY: CDI has emerged as one of the most common infections in the early transplant period. Recent studies have begun to address the epidemiology of disease, risk factors for, and outcomes after infection in the stem cell transplant. However, more research is needed to unravel the observed relationship between CDI and GVHD.