Etiology, clinical course and outcome of healthcare-associated bloodstream infections in patients with hematological malignancies: a retrospective study of 350 patients in a Finnish tertiary care hospital.

This retrospectively collected laboratory-based surveillance data includes 575 healthcare-associated bloodstream infections (BSIs) in 350 patients with hematological malignancy in Tampere University Hospital, Finland, during 1999-2001 and 2005-2010. The most common underlying diseases were acute myelogenous leukemia (n=283, 49%), followed by myeloma (n=87, 15%) and acute lymphocytic leukemia (n=76, 13%). The overall rate was 9.1 BSIs per 1000 patient-days. Gram-positive BSIs predominated and the most common pathogens were coagulase-negative staphylococci (23%), viridans streptococci (11%), enterococci (9%) and Escherichia coli (9%). Fungi caused 2% of BSIs. The 7-day and 28-day case fatalities were 5% and 10% and were highest in BSIs caused by P. aeruginosa (19% and 34%, respectively). The median age of patients with BSI has increased; it was 55.0 years during 1999-2001, compared to 59.0 years in 2005-2007 and 59.0 years in 2008-2010 (p<0.0001). Gram-positive bacteria predominated in this material. Case fatalities were low as compared to previous reports although the median age of patients increased.