Bacteremia after hematopoietic stem cell transplantation:: incidence and predictive value of surveillance cultures

We studied 622 transplants undertaken between 1982 and 2001 to: ( 1) determine the incidence, timing and etiology of bacteremias, and ( 2) examine the ability of routine surveillance cultures to predict bacteremias. A total of 404 episodes ( 0.65 episode per patient) occurred in 248 patients, due to coagulase- negative staphylococci ( n = 171, 42%), Gram- negative bacteria ( n = 129, 32%), streptococci ( n = 48, 12%), other Gram- positive bacteria ( n = 33, 8%), anaerobes ( n = 9, 2%) and fungi ( n = 14, 3%). Bacteremias were more frequent in allogeneic ( 0.96 episode/ patient) compared to autologous ( 0.44) transplants ( P < 0.0001). The overall incidence decreased from 0.92 episode/ patient until 1990 to 0.66 in 1991 - 1996 and 0.55 in 1997 - 2001 ( P < 0.0001), but this was only observed in autologous transplants. Among them, 212 ( 53%) occurred before hospital discharge and 192 ( 47%) thereafter. This proportion was lower for coagulase-negative staphylococci, other Gram- positive bacteria and Gram- negative bacteria compared to other agents ( P = 0.001). In 50% of the cases, the agent responsible for the bacteremic episode was present in routine surveillance cultures previously. In conclusion: ( 1) bacteremias remain a frequent complication, particularly in allogeneic transplantation, even long after hospital discharge; ( 2) routine surveillance cultures can predict bacteremias in 50% of the cases, but the practical impact of this observation is limited in view of the costs.