Clinical and microbiological characteristics of bloodstream infections among patients with haematological malignancies with and without neutropenia at a medical centre in northern Taiwan, 2008-2013

- Patients with haematological malignancy treated for bloodstream infection (BSI) at NTUH from 2008 to 2013 were reviewed.
- Of the 2090 non-duplicate BSI isolates, 1310 (62.7%) were recovered from patients with neutropenia.
- Of the Gram-negatives (53.7%), Escherichia coli (13.8%) was predominant, followed by Klebsiella pneumoniae (9.5%).
- MDR was identified in 21.8% of Acinetobacter calcoaceticus-baumannii complex and VRE in 46.6% of E. faecium isolates.
- Age ≥60 years, prior allogeneic transplantation, VRE BSI and shock were independent predictors of 14-day mortality (12.9%).

This study aimed to investigate the epidemiology and microbiology of bloodstream infections (BSIs) in patients with haematological malignancies. Clinical characteristics and microbiology of 2083 patients with haematological malignancy who were treated for BSI from 2008 to 2013 at a medical centre in Taiwan were retrospectively reviewed. Lymphoma (38.1%) was the most common, followed by acute myeloid leukaemia (30.9%). Of the 2090 non-duplicate BSI isolates, 1310 (62.7%) were recovered from patients with neutropenia. Of the Gram-negatives (53.7%), Escherichia coli was predominant (13.8%), followed by Klebsiella pneumoniae (9.5%), Acinetobacter calcoaceticus-baumannii (ACB) complex (5.7%) and Pseudomonas aeruginosa (4.0%). Of the Gram-positives (40.2%), coagulase-negative staphylococci were the most common (20.5%), followed by Enterococcus faecium (5.6%). Candida tropicalis (2.0%) was the most commonly encountered yeast (5.0%). Multidrug resistance (MDR) was identified in 21.8% of ACB complex isolates. Among the 57 Staphylococcus aureus isolates, 24 (42.1%) were resistant to oxacillin (MRSA), and among the 118 E. faecium isolates, 55 (46.6%) were resistant to vancomycin (VRE). The overall 14-day mortality rate was 12.9% (n = 269). There was no significant difference in 14-day mortality among patients with (13.4%) and without (11.9%) neutropenia (P = 0.315). Multivariate analysis revealed that age ≥60 years, prior allogeneic transplantation, BSI due to VRE (E. faecium) and shock were independent predictors of 14-day mortality. Gram-negative organisms continued to be the most common cause of BSI in patients with haematological malignancies during the period 2008-2013. There was a significant increase in the prevalence of VRE (E. faecium) and MDR-ACB complex isolates.