Fecal ESBL Escherichia coli carriage as a risk factor for bacteremia in patients with hematological malignancies

The purpose of this study is to evaluate the impact of fecal extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) colonization for bloodstream infection (BSI), clinical outcome, and costs in patients with hematologic malignancies (HM) and severe neutropenia. This is a cohort study, carried out at a cancer-referral hospital. The study population comprises patients with HM, hospitalized prior to administration of the first chemotherapy cycle. A stool culture was taken during the first 48 h; they were grouped as colonized by ESBL-EC or non-ESBL-EC. Patients were followed upon completion of chemotherapy or death. The sum of the days of antibiotics and the length of stay of all hospitalizations in the different cycles of chemotherapy were recorded. We included 126 patients with a recent diagnosis of HM, grouped as 63 patients colonized by ESBL-EC and 63 colonized by non-ESBL-EC, aged 42 +/- 16 years old, 78 males (62 %). BSI by ESBL-EC developed in 14 patients (22.2 %) colonized by the same strain and in 5 (7.9 %) in the group colonized with non-ESBL-EC. BSI by non-ESBL-EC was observed in 3 patients (4.7 %) colonized by ESBL-EC and in 17 (26.9 %) patients colonized by non-ESBL-EC. Colonization with ESBL-EC increased the risk of BSI by the same strain (relative risk (RR) = 3.4, 95 % confidence interval (95 % CI) 1.5-7.8, p = 0.001), shorter time to death (74 +/- 62 vs. 95 +/- 83 days, p < 0.001), longer hospital stay (64 +/- 39 vs. 48 +/- 32 days, p = 0.01), and higher infection-related costs ($6528 +/- $4348 vs. $4722 +/- $3173, p = 0.01). There was no difference in overall mortality between both groups. Fecal colonization by ESBL-EC is associated with increased risk of BSI by this strain, longer hospital stay, and higher related costs.