Risk factors for acquisition of CTX-M genes in pilgrims during Hajj 2013 and 2014

International audienceBackground: Mass gatherings, especially the Hajj pilgrimage, provide favourable conditions for bacterial transmission among participants, which might contribute to the international spread of ESBL-producing Enterobacteriaceae (ESBL-E). Objectives: Weconducted an analysis aimed at investigating risk factors for CTX-M gene (bla(CTX-M)) rectal carriage in 2013 and 2014 Hajj pilgrims. Methods: A total of 218 pilgrims provided paired pre- and post-Hajj rectal samples (2013, 129 pilgrims; 2014, 89 pilgrims). CTX-M genes in rectal samples were identified by PCR and confirmed by sequencing. Pilgrims' characteristics, including possible factors relating to ESBL acquisition, were collected and analysed using XLSTAT version 2016.05.34687 (Addinsoft). For the univariate analysis, the frequencies of nominal data were compared using Pearson's chi(2) test and Fisher's exact test, and the means of quantitative data were compared using Student's t-test. A difference was considered significant when P