Infection-Related Mortality After HSCT
INFECTION-related mortality accounted for most early deaths after hematopoietic stem cell transplantation (HSCT) in a center located in a high antimicrobial resistance setting, highlighting the clinical threat posed by resistant bacterial and fungal infections in this vulnerable population.
The study included 522 patients with hematologic malignancies who underwent HSCT between 2016 and 2024. Investigators assessed bloodstream infections and opportunistic infections occurring within the first 100 days after transplant, defining infection-related mortality as death primarily attributable to infectious complications.
At 30 days, 25 patients had died, representing 5% of the cohort. Of these deaths, 24, or 96%, were attributed to infections. By 100 days, 52 patients had died, equal to 10% of the cohort, with infections accounting for 42 deaths, or 80%.
Resistant Bloodstream Infections Shape Survival
Gram-negative bacteria dominated bloodstream infections, accounting for 73% of cases. Escherichia coli represented 31% and Klebsiella pneumoniae 30%, making them the most frequently identified pathogens.
Carbapenem resistance was especially high in Klebsiella pneumoniae, affecting 67% of isolates. The OXA-48 carbapenemase gene was the most common molecular resistance type, identified in 43% of Klebsiella pneumoniae cases. Carbapenem-resistant Klebsiella pneumoniae bacteremia was linked to significantly reduced 100-day survival and emerged as an important predictor of early mortality.
Pseudomonas aeruginosa bacteremia was also associated with poorer survival, underscoring the need for timely empirical therapy in centers where antimicrobial resistance is common.
Invasive Aspergillosis Adds Fungal Mortality Risk
Invasive aspergillosis significantly impaired survival across the full cohort and was particularly relevant among allogeneic HSCT recipients. In this subgroup of 139 patients, 100-day mortality reached 27%, while invasive aspergillosis occurred in 19% and carbapenem-resistant Klebsiella pneumoniae bacteremia in 17%.
Invasive aspergillosis occurred in 12% of all patients and was strongly associated with prolonged neutropenia and corticosteroid use, reinforcing the importance of fungal surveillance and prevention strategies in patients with sustained immune compromise.
These findings emphasize that infection-related mortality after HSCT remains a major challenge in high resistance settings. Optimized empirical therapy, antimicrobial stewardship, and strengthened infection prevention may be critical to improving early post-transplant survival.
Reference
İrkören P et al. Infection-related mortality after hematopoietic stem cell transplantation in a high antimicrobial resistance setting. Eur J Clin Microbiol Infect Dis. 2026;https://doi.org/10.1007/s10096-026-05481-w.
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