The Import and Spread of Antibiotic-Resistant Enterobacteriaceae by Healthy Travellers

Background International travel contributes to the dissemination of antimicrobial resistance. We examined the acquisition of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) during international travel, with a focus on predictive factors for acquisition, duration of colonisation and probability of onward transmission. The presented data were published before in The Lancet Infectious Diseases. Methods Within the prospective multicenter COMBAT study, 2001 Dutch travellers and 215 non-travelling household members were enrolled. Faecal samples and questionnaires on demographics, illnesses, and behavior were collected before and immediately after travel, and at 1, 3, 6 and 12 months after return. Samples were screened for the presence of ESBL-E. In post-travel samples, ESBL genes were sequenced and PCR with specific primers for plasmid-encoded beta-lactamase enzymes TEM, SHV, and CTX-M group 1, 2, 8, 9, and 25 were used to confirm the presence of ESBL genes in follow-up samples. Multivariable regression analyses and mathematical modelling were used to identify predictors for acquisition and sustained carriage, and to determine household transmission rates. Finding