Bloodstream Infections Affect 31.3% of Transplant Recipients, Carbapenem Resistance Linked to Poor Survival, Suggests Study

Although hematopoietic stem cell transplantation (HSCT) is rapidly expanding across India, post-transplant bacterial infections pose severe clinical hurdles, and while earlier regional reports indicated a 23.9% bacteremia incidence, contemporary Indian data addressing specific risk factors, evolving drug resistance, and survival impacts remained scarce. To address this crucial knowledge gap, Dr. Parikshit S. Prayag and colleagues from the Department of Infectious Diseases at Deenanath Mangeshkar Hospital & Research Center in Pune, Maharashtra, aimed to characterize the epidemiology, microbiological profiles, resistance patterns, risk factors, and overall survival outcomes of bacteremia in the first year following transplant.

Therefore, the retrospective single-center study evaluated 300 consecutive adult HSCT recipients in western India between 2018 and 2023, excluding pediatric patients, those lost to follow-up within one year, and cases with incomplete records. Utilizing automated culture systems, MALDI-TOF mass spectrometry, and multivariable regression, the investigators analyzed bacteremia incidence, microbial resistance profiles, clinical risk predictors, and one-year survival rates.

Key Clinical Findings of the Study Includes:

• High Incidental Burden: The study revealed that 31.3% of recipients (94 of 300) experienced 130 bacteremia episodes within one year post-transplantation, with 85.4% occurring during the initial 100 days at a median onset of 11 days.
• Gram-Negative Pathogen Predominance: The investigation demonstrated that gram-negative bacilli accounted for 79.2% of all episodes—primarily Klebsiella pneumoniae (37 cases) and Escherichia coli (28 cases)—whereas gram-positive pathogens comprised only 20.8%.
• Alarming Carbapenem Resistance: The analysis identified carbapenem resistance in 67.5% of Klebsiella pneumoniae, 87.5% of Acinetobacter baumannii, and 32.0% of Escherichia coli isolates, reflecting severe regional antimicrobial resistance.
• Key Independent Risk Factors: The study established that allogeneic transplant (odds ratio [OR] = 7.095, 95% confidence interval [CI] = 3.750–13.425; p < 0.001) and pre-existing diabetes mellitus (OR = 2.867, 95% CI = 1.246–6.596; p = 0.013) were significant independent risk predictors.
• Significant Survival Penalty: The research documented a significantly lower one-year overall survival rate of 58.5% in bacteremic patients compared to 86.9% in uninfected controls (p < 0.001), conferring an adjusted mortality hazard ratio of 1.939 (p = 0.017).

The results suggest that post-transplant bacteremia in India is predominantly driven by highly resistant Gram-negative pathogens, resulting in a significantly reduced mean survival time of 261.15 days in bacteremic patients compared to 330.73 days in uninfected individuals (p < 0.001). Furthermore, with 14-day and 28-day mortality rates reaching 6.9% and 14.6%, respectively, early bloodstream invasion remains a major contributor to post-transplant mortality.

These findings underscore the crucial need for transplant clinicians to enforce rigorous infection control protocols, practice vigilant central catheter care, and implement tailored antimicrobial stewardship programs based on local resistance patterns.

Although the study is constrained by its single-center retrospective design, exclusion of pediatric patients, and lack of prior antibiotic exposure data, prospective multicenter studies are warranted to further characterize evolving resistance patterns and validate effective management strategies.

Reference

Prayag PS, Patwardhan SA, Melinkeri SR, Dhupad SS, Tyagi SA, Rane T, et al. Bacteremia in the First Year after Hematopoietic Stem Cell Transplantation: A Single-center Experience from a Tertiary Care Center in India. Indian J Crit Care Med 2026;30(9):779–785.