Duration of colonization with extended-spectrum beta-lactamase-producing Escherichia coli in patients with travellers' diarrhoea.

Background: Resistant Enterobacteriaceae have become a worldwide epidemic during the last decade and are a great threat to health care worldwide. International travel is a major risk factor for becoming colonized with extended-spectrum beta-lactamase (ESBL)-producing bacteria. Data on the persistence of colonization with ESBL-producing bacteria in the faecal flora are limited.Methods: A prospective cohort study was performed between October 2007 and October 2010. Fifty-eight patients with faecal carriage of ESBL-producing Escherichia coli from a previous study of patients with travellers' diarrhoea were included.Results: Forty-one of the patients had a complete follow-up. Ten of these patients (24%) carried ESBL-producing E. coli at the first follow-up point (3-8 months), of whom 4 had a new ESBL strain. At the 3-y follow-up, 4 patients carried ESBL (10%), of whom 1 had 2 new ESBL strains.Conclusions: The long duration of ESBL carriage is worrisome. These carriers may be an important source of the spread of ESBLs in the population and this has implications for the clinical management of patients.