A practical update on the epidemiology and risk factors for the emergence and mortality of bloodstream infections from real-world data of 3014 hematological malignancy patients receiving chemotherapy

Background: Bloodstream infection (BSI) is a common and serious complication after patients with hematologic malignancies (HM) receiving chemotherapy. This study examined real-world data seeking to characterize HM BSI and identify risk factors for BSI emergence and mortality. Methods: We retrospectively analyzed the pathogenic epidemiology, antibiotic resistance, and BSI risk factors in a single-center cohort including 3014 consecutive patients with HM receiving chemotherapy between 2013 and 2016. Results of the pathogenic epidemiology were validated via comparison to available reported data. Results: We found that 725 patients (24.1%) had BSIs. Gram-negative (G-) bacteria represented 64.7% of the 744 isolated pathogenic strains, while Gram-positive (G+) bacteria and fungi accounted for 27.7% and 7.7% of the BSIs, respectively. The most common isolates were Klebsiella pneumoniae (19.2%), and 95.1% of the multidrug-resistant strains (MDR) were extended-spectrum beta-lactamase producing strains. G-bacteria were the main microflora responsible for BSI in our cohort of Chinese HM patients compared to studies in developed countries or in neutropenic children with HM or solid tumors. Multivariate analysis revealed that male sex, age >= 45 and < 65 yr, hospital length of stay >= 9d, neutropenia >= 7d before cultures, >= 2 antibiotics, and infections (gastrointestinal, perirectal, or urinary tract) independently predicted BSI emergence. Furthermore, age >= 65 yr, neutropenia >= 7d before blood cultures, no HM remission, lower white blood cell count, >= 3 antibiotics, respiratory infections, and Acinetobacter baumannii and Stenotrophomonas maltophilia BSI were independent predictors of 30-day mortality. Conclusions: G-bacteria were the predominant microflora during the study period and antibiotic resistance levels of the pathogens detected were high, especially for MDR strains. The mortality of BSI patients was high in this large cohort. Close attention should be paid to the risk factors identified here to facilitate timely and effective clinical management of such patients.

Automated summary

This study focused on bloodstream infections (BSI) in patients with hematologic malignancies (HM) receiving chemotherapy, finding a high BSI rate primarily caused by Gram-negative bacteria, especially multidrug-resistant (MDR) strains. Various factors like gender, age, hospital stays, neutropenia, antibiotic use, and infection sites were found to predict BSI emergence, while factors like age, neutropenia, HM remission status, white blood cell count, antibiotic use, infection sites, and specific bacterial strains predicted 30-day mortality. High attention should be paid to managing these risk factors for effective clinical care.