Bacteremia in the First Year after Hematopoietic Stem Cell Transplantation: A Single-center Experience from a Tertiary Care Center in India

Background and aims: Bacteremia remains a major cause of morbidity and mortality following hematopoietic stem cell transplantation (HSCT), particularly in regions with high antimicrobial resistance.Data from India describing the epidemiology and outcomes of bacteremia after HSCT remain limited. Patients and methods:We conducted a retrospective single-center study of 300 adult patients who underwent HSCT between January 2018 and December 2023 at a tertiary care center in western India.Episodes of bacteremia occurring within 1 year after HSCT were analyzed for risk factors, microbiological profile, antimicrobial resistance patterns, clinical characteristics, outcomes, and impact on survival.Multivariable logistic regression was performed to identify independent risk factors associated with bacteremia.Results: Ninety-four patients (31.3%) developed 130 episodes of bacteremia within 1 year after HSCT.In multivariable analysis, diabetes mellitus [odds ratio (OR) = 2.867, 95% confidence interval (CI) = 1.246-6.596;p = 0.013] and allogeneic HSCT (OR = 7.095, 95% CI = 3.750-13.425;p < 0.001) were independently associated with bacteremia.Gram-negative organisms accounted for 79.2% of episodes, with Klebsiella pneumoniae being the most common pathogen.High carbapenem resistance rates were observed among K. pneumoniae (67.5%) and Acinetobacter baumannii (87.5%) isolates.Most episodes (85.4%) occurred within the first 100 days after HSCT.The 14-and 28-day mortality rates were 6.9 and 14.6%, respectively.Patients with bacteremia had significantly lower overall survival compared with those without bacteremia (p < 0.001).Conclusions: Bacteremia following HSCT in India is predominantly caused by multidrug-resistant gram-negative organisms and is associated with significantly reduced survival.These findings highlight the importance of robust antimicrobial stewardship and stringent infection control practices in HSCT settings.