Epidemiology and risk factors for bloodstream infections after allogeneic hematopoietic stem cell transplantion

A total of 315 patients who underwent allogeneic Hematopoietic Stem Cell Transplantation (HSCT) during a 4-year period were analysed with the aim of collecting information on bloodstream infections (BSI). Eighty-four patients (27%) developed 112 BSI, with a cumulative risk of 20.6% at 30 days and 27.7% at 180 days. Overall, 127 pathogens were isolated, 95 (75%) gram-positive cocci, 27 (21%) gram-negative rods and 5 (4%) fungi. Enterococcus sp. accounted for 46 of 127 (36%) isolates. In a multivariable analysis only including baseline factors, the type of transplant was the only factor significantly associated with the risk of BSI and the risk was higher for patients receiving transplant from mismatched or unrelated donors. In a case-control study aimed at evaluating the predictive role of additional factors during transplant, the risk appeared to be higher in patients with a positive CMV antigenemia (p = 0.03; OR of 4.82; 95% CI, 1.21-19.17), long duration of severe granulocytopenia (p = 0.015; OR 7.53; 95% CI, 1.92 - 29.58) and lower platelet count (p < 0.001; OR 0.14; 95% CI, 0.05 - 0.40). By day 180 post-transplant, 87 (28%) out of 314 patients had died. The cumulative risk of death was significantly higher among patients with BSI than among other patients.