Effect of quinolone prophylaxis discontinuation during pre-engraftment neutropenia on incidence, mortality, and aetiology of bloodstream infections in hematopoietic stem-cell transplant recipients: a systematic review and meta-analysis

Background Bloodstream infections (BSIs) are a major complication during pre-engraftment neutropenia in haematopoietic-stem cell transplant (HSCT) recipients. Quinolone prophylaxis reduces BSIs but increases multidrug-resistance bacterial infections. We aimed to assess the impact of discontinuing quinolone prophylaxis in adult HSCT recipients. Methods We performed a systematic review with meta-analysis. Five databases were searched on May 20, 2025. Studies were eligible for inclusion if they reported clinical characteristics of adult HSCT recipients and outcomes following the discontinuation of prophylaxis. Data extraction and quality assessment were performed independently by two reviewers. Meta-analysis was performed and pooled risk ratios with 95%CI calculated using a random-effects model. Results Ten studies including 2,363 HSCT recipients (1,190 with and 1,173 without prophylaxis) were included. Most were allogeneic-HSCT (53.1%). Prophylaxis was associated with a lower risk of BSIs due to any microorganism (pooled risk ratio: 0.69;95%CI0.54-0.87;p-value=0.002;I2=61%) and due to Gram-negative bacteria (pooled risk ratio: 0.49;95%CI0.33-0.74;p-value=0.0007;I2=71%). In the overall population, there was no significant difference in resistant infections. In patients with Gram-negative BSIs, prophylaxis was associated with a higher risk of quinolone-resistant (pooled risk ratio: 2.35;95%CI1.68-3.29;p-value<0.00001;I2=27%) and carbapenem-resistant microorganisms (pooled risk ratio:5.32;95%CI 1.08-26.16; p-value =0.04;I2=69%). Discontinuation was not associated with a statistically increased infection-related mortality (pooled risk ratio:1.26;95%CI: 0.71-2.23;p-value=0.43;I2=0%). Conclusions Discontinuation of quinolone prophylaxis was associated with an elevated incidence of BSIs, without a concomitant reduction in the overall burden of antimicrobial resistance. Importantly, infection-related mortality did not increase to a statistically significant extent. Furthermore, Gram-negative BSIs occurring after discontinuation were less likely to exhibit resistance to quinolones or carbapenems.