Epidemiology of bloodstream infections in patients with chronic lymphocytic leukemia: a longitudinal nation-wide cohort study

Patients with chronic lymphocytic leukemia (CLL) have a high risk of bloodstream infections (BSI). BSI cause significant morbidity and mortality among CLL patients; approximately one-third of fatalities in CLL list infections as cause of death. All CLL patients in Denmark diagnosed between 2008 and 2016 were followed through registries for the event of a BSI. Patient characteristics and bacterial findings were analyzed separately for treatment-naive and treated patients. A total of 3677 and 1020 patients with CLL were followed as treatment-naive and treated patients, respectively. We identified 145 cases of Gram-positive bacteremia. Streptococcus pneumoniae accounted for 32 (22%) cases, while Staphylococcus aureus was found 30 times (21%). Gram-negative microorganisms were found in 166 (46%) cases. Escherichia coli accounted for 77 (46%) cases. Lastly, we identified six episodes of candidemia of which five (83%) were fatal within 30 days of the infection. Based on increased frequency of S. pneumoniae and Pseudomonas aeruginosa and the high mortality of candidemia in CLL, empirical antibiotics with double coverage for S. pneumoniae and P. aeruginosa is recommended; upon suspected or proven candidemia, treatment with broad-spectrum fungicidal agents are recommended.