Risk of Bacterial Infection in Pediatric Hematopoietic Stem Cell Transplant Patients Receiving Cephalosporin Prophylaxis
Authors: Berger Amanda , Frangoul Haydar , Bruce Katie , Ampah Steve 
Published: October 2019

Abstract
Abstract 4497

Background:
At our institution, all hematopoietic stem cell transplant (HSCT) patients receive a prophylactic cephalosporin starting either at Day -1 of transplant or when the absolute neutrophil count (ANC) is below 500 cells/mm3. Cephalosporin prophylaxis continues until neutrophil engraftment (ANC≥500 cells/mm3 for three consecutive days). We sought to determine the incidence of bacterial infections among pediatric recipients of HSCT during the immediate post-transplant period.

Methods:
This retrospective review examined all HSCT recipients from September 1999 to August 2011. Data collected included gender, age at transplant, diagnosis, type of transplant, graft-versus-host disease and use of radiation. Post-transplant data collected included time to engraftment, antibacterial prophylaxis regimen administered, and number of positive bacterial cultures during post-transplant neutropenia, including organisms isolated and susceptibilities to the prophylactic cephalosporin administered. Patients with primary immune deficiency were excluded from this analysis. To evaluate the effect of prophylaxis we also collected data on all patients with acute myeloid leukemia (AML) at our center during the same time period. AML patients do not receive any prophylactic antibiotics. For AML patients, data collected included gender, age at time of therapy, and number of positive bacterial cultures during post-chemotherapy neutropenia, including organisms isolated and susceptibilities to cephalosporin.

Results:
A total of 287 stem cell transplant patients with a median age 8.6 years (range 0.4–25) were included. There were 165 (57%) males, 236 (82%) had malignant diseases and 123 (43%) received a total body irradiation based regimen. 71 (25%) received an autologous, and 216 (75%) received allogeneic transplant (78 related, 138 unrelated, 37 cord blood). The median time to engraftment was 17 days (range (8–78). A total of 96 AML patients were included with a median age of 6.6 years (range 0.6–22). The median time of neutropenia was 32 days (range 15–115). The HSCT and AML patients were comparable in age and gender. A total of 36 (13%) transplants were complicated by at least one bacterial infection. The infections (n=57) included 49 gram positive, 7 gram negative, 1 atypical. A total of 35 (36%) chemotherapy cycles were complicated by at least one bacterial infection. A total of 44 infections occurred in the AML patients (36 gram positive, 7 gram negative, 1 atypical). When comparing the two groups, the AML patients had significantly more bacterial infections than the HSCT recipients (P<0.001). Among the HSCT group, using multivariate analysis neither age at transplant, gender, related versus unrelated donor, use of TBI, or use of steroids were associated with increased risk of bacterial infection. However, there was increased risk of bacterial infections in patients with malignant disease (P=0.046).

Conclusion:
The use of cephalosporin prophylaxis in pediatric HSCT recipients resulted in a lower number of bacterial infections than has been previously reported. HSCT patients had significantly less infections compared to AML patients who received no bacterial prophylaxis.

Disclosures:
No relevant conflicts of interest to declare.