Clostridium difficile infection in Chilean patients submitted to hematopoietic stem cell transplantation.

Introduction: Patients submitted to hematopoietic stem cell transplantation have an increased risk of Clostridium difficile infection and multiple risk factors have been identified. Published reports have indicated an incidence from 9% to 30% of transplant patients however to date there is no information about infection in these patients in Chile.

Methods: A retrospective analysis was performed of patients who developed C. difficile infection after hematopoietic stem cell transplantations from 2000 to 2013. Statistical analysis used the Statistical Package for the Social Sciences software.

Results: Two hundred and fifty patients were studied (mean age: 39 years; range: 17-69), with 147 (59%) receiving allogeneic transplants and 103 (41%) receiving autologous transplants. One hundred and ninety-two (77%) patients had diarrhea, with 25 (10%) cases of C. difficile infection being confirmed. Twenty infected patients had undergone allogeneic transplants, of which ten had acute lymphoblastic leukemia, three had acute myeloid leukemia and seven had other diseases (myelodysplastic syndrome, chronic myeloid leukemia, severe aplastic anemia). In the autologous transplant group, five patients had C. difficile infection; two had multiple myeloma, one had amyloidosis, one had acute myeloid leukemia and one had germinal carcinoma. The overall incidence of C. difficile infection was 4% within the first week, 6.4% in the first month and 10% in one year, with no difference in overall survival between infected and non-infected groups (72.0% vs. 67.6%, respectively; p-value=0.56). Patients infected after allogeneic transplants had a slower time to neutrophil engraftment compared to non-infected patients (17.5 vs. 14.9 days, respectively; p-value=0.008). In the autologous transplant group there was no significant difference in the neutrophil engraftment time between infected and non-infected patients (12.5 days vs. 11.8 days, respectively; p-value=0.71). In the allogeneic transplant group, the median time to acute graft-versus-host disease was similar between the two groups (p-value=0.08), as was the incidence of grades 1-4 acute graft-versus-host disease (40% vs. 48%; p-value >0.05).

Conclusion: The incidence of C. difficile infection after hematopoietic stem cell transplantation was low, with a significant number of cases occurring shortly after transplantation. Allogeneic transplants had a three-time higher risk of infection compared to autologous transplants, but this was not associated with increased mortality, decreased overall survival or higher risk of acute graft-versus-host disease.