Background. One-third of the 100 million travelers to the tropics annually acquire extended-spectrum β-lactamase (ESBL)- producing Enterobacteriaceae (ESBL-PE), with undefined clinical consequences. Methods. Symptoms suggesting Enterobacteriaceae infections were recorded prospectively among 430 Finnish travelers, 90 (21%) of whom acquired ESBL-PE abroad. ESBL-PE isolates underwent polymerase chain reaction-based detection of diarrheagenic Escherichia coli (DEC) pathotypes (enteroaggregative E. coli [EAEC], enteropathogenic E. coli [EPEC], enterotoxigenic E. coli [ETEC], enteroinvasive E. coli, and Shiga toxin-producing E. coli), and extraintestinal pathogenic/uropathogenic E. coli (ExPEC/UPEC). Laboratory-confirmed ESBL-PE infections were surveyed 5 years before and after travel. Results. Among the 90 ESBL-PE carriers, manifestations of Enterobacteriaceae infection included travelers' diarrhea (TD) (75/90 subjects) and urinary tract infection (UTI) (3/90). The carriers had 96 ESBL-producing E. coli isolates, 51% exhibiting a molecular pathotype: 13 (14%) were DEC (10 EAEC, 2 EPEC, 1 ETEC) (12 associated with TD) and 39 (41%) ExPEC/UPEC (none associated with UTI). Of ESBL-PE, 3 (3%) were ExPEC/UPEC-EAEC hybrids (2 associated with diarrhea, none with UTI). Potential ESBL-PE infections were detected in 15 of 90 subjects (17%). The 10-year medical record survey identified 4 laboratory-confirmed ESBL-PE infections among the 430 travelers, all in subjects who screened ESBL-PE negative after returning home from their index journeys but had traveled abroad before their infection episodes. Conclusions. Half of all travel-acquired ESBL-producing E. coli strains qualified molecularly as pathogens. Extraintestinal and uropathogenic pathotypes outnumbered enteric pathotypes (41% vs 14%), yet the latter correlated more closely with symptomatic infection (0% vs 92%). Despite more ESBL-PE strains qualifying as ExPEC/UPEC than DEC, travel-acquired ESBL-PE are more often associated with TD than UTI.
Bibliographical noteFunding Information:
Financial support. The work was supported by the Finnish Governmental Subsidy for Health Science Research; the Scandinavion Society for Antimicrobial Chemotherapy Foundation; the Paulo Foundation; the Sigrid Jusélius Foundation; and the Finnish Cultural Foundation. This work also was supported in part by the Office of Research and Development, US Department of Veterans Affairs (grant numbers 1 I01 CX000920-01 and 2I01CX000920-04 to J. R. J.).
Potential conflicts of interest. A. K. has received honoraria for lectures from Valneva and Immuron, and investigator-initiated grants from Pfizer and Valneva. J. R. J. has had research contracts or consultancies with Achaogen, Allergan, Crucell/Janssen, IDGenomics, Merck, Shionogi, Syntiron, Melinta, and Tetraphase, and holds patent applications for tests to detect E. coli strains. J. K. is an employee of Mobidiag, which develops diagnostic tests for infectious diseases, none of which were used in the study. All other authors report no potential conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.
© The Author(s) 2019.
- Extended-spectrum beta-lactamase