Clostridium difficile infection in the hematopoietic unit: a meta-analysis of published studies.

Hematopoietic stem cell transplant (HSCT) recipients are at high risk of contracting Clostridium difficile infection (CDI). We systematically searched the PubMed and EMBASE databases through March 2014 and performed a random-effects meta-analysis to estimate the prevalence and trends of CDI over time. Among 48 eligible articles that included 12,025 patients at risk, we estimated that 7.9% (95% confidence interval [CI], 6.5% to 9.5%) of HSCT patients are diagnosed with CDI during the peri-transplantation and late post-transplantation periods, an estimation that is relatively consistent across studies (τ(2) = .032). Prevalence of CDI is significantly higher among the 5120 allogeneic patients (9.3% [95% CI, 7.0% to 11.9%]), compared with the 4665 autologous patients (5.2% [95% CI, 3.8% to 6.9%]) (P = .02), and as many as 1 of 10 allogeneic transplant recipients are expected to be diagnosed with CDI compared with 1 of 20 autologous transplantation patients. However, this difference did not reach statistical significance when stratified data from the same centers were examined (P = .11). Importantly, we found an increasing trend of CDI diagnosis both worldwide (P = .02) and across studies conducted in North America (P = .03) over the last 34 years. Notably, studies with a follow-up period that extended through the late post-transplantation period (after day +100) had a similar prevalence of CDI as those that followed patients only during the peri-transplantation period (up to day +100) (P = .94). In summary, CDI is common in the hematopoietic transplantation setting and the majority of infections occur in the peri-transplantation period. The prevalence is almost 9-times higher than that reported among all hospital stays, with an increasing trend over time.