title: Antimicrobials increase travelers' risk of colonization by extended-spectrum betalactamase-producing Enterobacteriaceae.
abstract: BACKGROUND
  More than 300 million travelers visit regions with poor hygiene annually. A significant percentage of them become colonized by resistant intestinal bacteria such as extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) and may transmit the strains to others and to medical care settings when they return home. Despite the threats to global healthcare caused by an upsurge in antimicrobial resistance, no effort has been centered on prevention of colonization while traveling.
  
  
  METHODS
  Stool samples were collected from 430 Finns before and after traveling outside Scandinavia. All specimens were analyzed for ESBL- and carbapenemase-producing Enterobacteriaceae (CPE). Questionnaires were used to survey volunteers about use of antimicrobials as well as other potential risk factors. The results were subjected to multivariable analysis.
  
  
  RESULTS
  Twenty-one percent (90/430) of the travelers became colonized by ESBL-PE and none by CPE. Geographic region, occurrence of travelers' diarrhea (TD), age, and use of antimicrobial (AB) for TD were identified as independent risk factors predisposing to contracting ESBL-PE. Eleven percent of those in subgroup TD-AB-, 21% in TD+AB-, and 37% in TD+AB+ acquired ESBL-PE. The risk proved to be highest in South Asia (46%); 23% became colonized in subgroup TD-AB-, 47% in TD+AB-, and 80% in TD+AB+. In Southeast Asia, the rates were 14%, 37%, and 69%, respectively.
  
  
  CONCLUSIONS
  TD and antimicrobials for TD proved to be independent risk factors, with up to 80% of TD+AB+ travelers contracting ESBL-PE. In modern pre-travel counseling for those visiting high-risk regions, travelers should be advised against taking antibiotics for mild or moderate TD.
authors.affiliation: Department of Clinical Medicine, University of Helsinki Division of Infectious Diseases, Department of Medicine, Helsinki University Hospital Department of Bacteriology and Immunology, University of Helsinki Aava Travel Clinic, Medical Centre Aava.
authors.forename: Anu
authors.initials: A
authors.lastname: Kantele
authors.affiliation: Department of Clinical Medicine, University of Helsinki Division of Infectious Diseases, Department of Medicine, Helsinki University Hospital.
authors.forename: Tinja
authors.initials: T
authors.lastname: Lääveri
authors.affiliation: Department of Clinical Microbiology, Helsinki University Hospital, University of Helsinki.
authors.forename: Sointu
authors.initials: S
authors.lastname: Mero
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Helsinki University Hospital Department of Bacteriology and Immunology, University of Helsinki.
authors.forename: Katri
authors.initials: K
authors.lastname: Vilkman
authors.affiliation: Department of Bacteriology and Immunology, University of Helsinki.
authors.forename: Sari H
authors.initials: SH
authors.lastname: Pakkanen
authors.affiliation: National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Ollgren
authors.affiliation: Department of Clinical Microbiology, Helsinki University Hospital, University of Helsinki.
authors.forename: Jenni
authors.initials: J
authors.lastname: Antikainen
authors.affiliation: Department of Clinical Microbiology, Helsinki University Hospital, University of Helsinki.
authors.forename: Juha
authors.initials: J
authors.lastname: Kirveskari
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001208:Asia / Q000453:epidemiology; D001210:Asia, Southeastern / Q000453:epidemiology; D001426:Bacterial Proteins / Q000096:biosynthesis; D015984:Causality; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000188:drug therapy / Q000453:epidemiology; D004755:Enterobacteriaceae / Q000201:enzymology / Q000254:growth & development* / Q000302:isolation & purification*; D004756:Enterobacteriaceae Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D005243:Feces / Q000382:microbiology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014195:Travel; D055815:Young Adult; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases; C063912:carbapenemase
keywords: ESBL; antimicrobials; colonization; travel; travelers’ diarrhea