Healthcare-associated blood stream infections in hematological patients in Finland during the years 2006-2016.

OBJECTIVES The aim was to identify the clinical characteristics, outcome and antimicrobial susceptibility of healthcare-associated bloodstream infections (BSIs) in hematological patients. METHODS This retrospectively collected laboratory-based surveillance data includes 3404 healthcare-associated BSIs in 2296 patients with a hematological malignancy in hospitals participating in the Finnish Hospital Infection Program from January 1, 2006 to December 31, 2016. RESULTS The most common underlying diseases were acute myelogenous leukemia (35%) and non-Hodgkin lymphoma (22%). Gram-positive organisms accounted for 60-46% and gram-negative organisms for 24-36% of BSIs in 2006-2016. The most common causative organism was coagulase negative staphylococci (CoNS) (n=731). The 7 and 28-day case fatality rates were 5.2% and 11.4%, respectively, and was highest in BSIs caused by Candida species (10.8% and 30.8%). The median age of patients increased from 59 years in 2006-2008 to 62 years in 2015-2016 (p<0.01). Five percent of S. aureus isolates were resistant to methicillin and five percent of Pseudomonas aeruginosa isolates were multidrug-resistant. Four percent of Klebsiella and seven percent of E. coli isolates were resistant to ceftatzidime. CONCLUSIONS The proportion of gram-positive bacteria decreased and gram-negative bacteria increased over time. The case fatality rate was low and the median age of patients increased during the study.