Purpose: The length of neutropenia has a significant impact on the incidence of bloodstream infection (BSI) in cancer patients, but limited information is available about the pathogen distribution in late BSI.
Methods: Between 2002 and 2014, BSI episodes in patients with neutropenia receiving chemotherapy for hematologic malignancies were prospectively identified by multicenter, active surveillance in Germany, Switzerland and Austria. The incidence of first BSI episodes, their microbiology and time to BSI onset during the first episode of neutropenia of 15,988 patients are described.
Results: The incidence rate of BSI episodes was 14.7, 8.7, and 4.7 per 1000 patient-days in the first, second, and third week of neutropenia, respectively. BSI developed after a median of 5 days of neutropenia (interquartile range [IQR] 3-10 days). The medium duration of neutropenia to BSI onset was 4 days in Escherichia coli (IQR 3-7 days), Klebsiella spp. (2-8 days), and Staphylococcus aureus (3-6 days). In contrast, BSI due to Enterococcus faecium occurred after a median of 9 days (IQR 6-14 days; p < 0.001 vs. other BSI). Late onset of BSI (occurring after the first week of neutropenia) was also observed for Stenotrophomonas maltophilia (12 days, IQR 7-17 days; p < 0.001), and non-albicans Candida spp. (13 days, IQR 8-19 days; p < 0.001).
Conclusions: Over the course of neutropenia, the proportion of difficult to treat pathogens such as E. faecium, S. maltophilia, and Candida spp. increased. Among other factors, prior duration of neutropenia may help to guide empiric antimicrobial treatment in febrile neutropenia.
Keywords: Bacteremia; Bloodstream infection; Hematologic malignancy; Neutropenia.