Microbiologically documented infections following peripheral blood stem cell transplantation: single center...

This study was performed to assess the incidence of infectious complications in patients undergoing autologous and allogeneic hematopoietic stem cell transplantation (HSCT). The characteristics of microbiologically documented infections in 114 consecutive patients undergoing HSCT (84 autologous, 30 allogeneic) were analyzed. Conditioning and the pre-engraftment period until one month was defined as the early period; the post-engraftment period until one year was defined as the late period. All patients received antibiotic prophylaxis and hematopoietic growth factors during neutropenia. Febrile patients received imipenem-cilastatin or cefepime plus amikacin or ceftazidime plus amikacin. A total of 117 episodes with microbiologically documented infections were seen 90 of 114 patients and 79% of the patients experienced at least one febrile episode during their post-transplant course. Of these episodes, 69 (59%) were in the early period and 48 (41%) were in the late period. In the early period, 38.8% of causative organisms were gram-positive, 51.5% were gramnegative and 7.7% were fungi. The most common pathogens were coagulase-negative Staphylococcus (CoNS) and E. coli in the early period. In the late period, 44.6% of causative organisms were gram-positive, 44.6% were gram-negative and 6.8% were fungi. CoNS and E. coli were also the most commonly isolated agents in this period. Resistance to methicillin was detected in 47.4% of S. aureus and 86.5% of CoNS isolates. The isolation rate was in accordance with previous reports; similar percentages of gram-positive and gram-negative isolates were found in patients undergoing HSCT in both periods. However, a remarkably low rate of viridans streptococci and fungi were observed. The spectrum of pathogens detected in these cases serves as the basis for recommendations on the choice of empiric antimicrobial treatment regimens. Therefore, studies reporting local microbiological findings are necessary. We suggest that local microbiologic surveillance should be known before empiric antimicrobial therapy is started in each institution.