A multicentre cohort study on colonization and infection with ESBL-producing Enterobacteriaceae in high-risk patients with haematological malignancies

Received 20 March 2014; returned 4 June 2014; revised 9 July 2014; accepted 15 July 2014Background: Bloodstream infections (BSIs) caused by enterobacteria remain a leading cause of mortality inpatients with chemotherapy-induced neutropenia. The rate and type of colonization and infection with ESBL-producing Enterobacteriaceae (ESBL-E) and their mode of transmission in German cancer centres is largelyunknown.Methods: We performed a prospective, observational study at five German university-based haematologydepartments. Participating sites screened for intestinal ESBL-E colonization within 72 h of admission, every10+2 days thereafter and before discharge. Three of the five centres performed contact isolation for patientscolonized or infected with ESBL-E. Molecular characterization of resistance mechanisms and epidemiologicaltyping of isolates by repetitive extragenic palindromic PCR (rep-PCR) and PFGE was performed to assess straintransmission between patients.Results: Between October 2011 and December 2012, 719 hospitalizations of 497 haematological high-riskpatients comprising 20143 patient-days were analysed. Mean duration of in-hospital stay was 36.6 days(range: 2–159 days). ESBL-E were identified from screening samples (82.8%Escherichia coliand 14.6%Klebsiella pneumoniae) in 55/497 patients (11.1%; range by centre: 5.8%–23.1%). PFGE and rep-PCR revealedonlyasinglecaseofpotentialcross-transmissionamongtwopatientscolonizedwithK.pneumoniae.Sixepisodesof BSI with ESBL-E were observed. Multivariate analysis revealed previous colonization with ESBL-E as the mostimportant risk factor for BSI with ESBL-E (OR 52.00; 95% CI 5.71–473.89).Conclusions: Even though BSI with ESBL-E is still rare in this high-risk population, colonization rates are substan-tial and vary considerably between centres. In-hospital transmission of ESBL-E as assessed by molecular typingwas the exception.Keywords: febrile neutropenia, bacteraemia, bloodstream infections, intestinal colonization, infection control, contact isolation