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.

We sought to describe the epidemiology of Clostridium difficile infection (CDI) among adult recipients of autologous hematopoietic stem cell transplantation (auto-HSCT) within the first year after HSCT in centers with variable epidemiology of hypertoxigenic strains. A multicenter, retrospective nested case-control study was conducted among 873 auto-HSCT recipients at Johns Hopkins Hospital (JHH) and Hôpital Maisonneuve-Rosemont (HMR) between January 2003 and December 2008. Despite center differences in the prevalence of NAP-1 strains during the study period (21% to 43% at JHH versus 80% to 84% in HMR), the 1-year incidence of CDI was similar in the 2 hospitals (6.2% at JHH versus 5.7% at HMR). The median time to infection was 11 days (interquartile range, 1 to 27 days). In case-control analyses, grade ≥2 mucositis (odds ratio [OR], 3.00; P = .02) and receipt of a fourth-generation cephalosporin (OR, 2.76; P = .04) were identified as predictors for CDI. Mucositis was the strongest predictor of risk for CDI in multivariate analysis (adjusted OR, 2.77; P = .03). CDI is a common and early complication of auto-HSCT. Treatment-related gastrointestinal mucosal damage, along with the potentially modifiable risk of antimicrobial exposure, influence the risk for CDI early after auto-HSCT.

Clostridium difficile infection (CDI) is a leading nosocomial disease estimated to cause nearly half a million cases in the United States annually. Recurrent CDI (rCDI) affects ~25% of patients after completion of standard of care therapy and is associated with substantial health care costs and a negative impact on patient’s overall markers of quality of life. Bezlotoxumab is the first of its kind monoclonal antibody directed against C. difficile toxin B and indicated for prevention of rCDI in at-risk patients. For the present review, we assessed English-language studies evaluating the clinical efficacy, safety, and pharmacokinetics of bezlotoxumab in humans. Relevant studies were obtained through PubMed, Embase, Cochrane database library, Web of Science, and clinicaltrials.gov. Overall, bezlotoxumab demonstrated a 40% relative reduction rate (absolute rate reduction of ~10%) and a number needed to treat of 10 patients with a favorable safety profile. Special populations, including the elderly, immunocompromised, and patients with end-stage renal disease were evaluated in post hoc analyses with a similarly favorable reduction in rCDI. This review presents and interprets the most recent safety data and the clinical application of bezlotoxumab, highlighting specific high-risk patient populations.